TITTLE:
DEVELOPMENT OF BIOPLASTICS FILM USING CASSAVA/TAPIOCA FLOUR AS THE SOURCE OF STARCH AND TO STUDY THE EFFECT OF GLYCEROL AS THE PLASTICIZER. BY: ADAM RASHID BIN NOOR RASHID (AN120091) CHANG WEN QI (AN120195) KHAIRUL ANWAR BIN ROSLI (AN120228) MUHAMMAD AZHIM BIN ABDUL HALIM (AN120019) NOR HAZLIZA BINTI MAT SIRIP (AN120015) SYAHIRA SYAELLA BINTI SALLEH (AN120014) TAN KIAN MENG (AN120214)
CHEMICAL PROCESS AND SUSTAINABILITY (BNQ20603)
DEPARTMENT OF CHEMICAL ENGINEERING TECHNOLOGY FACULTY OF ENGINNERING TECHNOLOGY UNIVERSITI TUN HUSSEIN ONN MALAYSIA
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First of all, with consent from Allah, we were given a good health to handle a project about bioplastic. A special appreciation was expressed to our lecturers which is Dr Mazatusziha Binti Ahmad for willing to spend her time and energy to listen to our problems and gives advice to us. Her advice and knowledge has helped us to finish this project efficiently. Furthermore, we would also like to express our gratitude towards laboratory assistants at MTKK laboratory leads by Madam Aziah who gave us permission to use the laboratory and assist us in using the equipment’s in the laboratory. A special thanks goes to the staff involved who gave a lot of useful information to us about our project. Last but not least, we would like to thank our classmates, family and friends for their support. Without their support, the project will not be finished within the limited time frame.
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TABLE OF CONTENTS
CHAPTER
1
TITLE
PAGE
TITTLE
i
ACKNOWLEDGEMENT
ii
ABSTRACT
iii
LIST OF TABLES
iv
LIST OF GRAPH
iv
LIST OF FIGURES
iv
INTRODUCTION
1.1 Current and Future Development
1-2
1.2 Problem Statements
3
1.3 Objective of the Study
4
1.4 Significance of the Study
4
1.5 Scopes of the Study
5
2
LITERATURE REVIEW
3
METHODOLOGY
6-8
3.1 Materials
9
3.2 Apparatus
9
3.3 Making Process
9
3.3.1 Procedure making the plastic film
9-10
3.4 Testing Technique 3.4.1 Water Absorption ASTM D570
11
3.4.2 Comparison of Bio-Plastics and
12
Petrochemical Plastics
4
RESULT AND DISCUSSION
4.2 Result of Testing 4.2.1 Result Water Absorption ASTM D570 4.2.2 Comparison of Bio-Plastics and Petrochemical
13-15 16
Plastics 4.2.2.1 How Bio-Plastic Different from
16-17
Petroleum Based Plastic?
5
CONCLUSION
5.1 Conclusions
18-19
5.2 Recommendations
20
5.3 Limitations and Solutions
21
REFERENCES
22
APPENDICES
23-26
CHAPTER 1 INTRODUCTION The introductory chapter comprises of detailed impetus that initiate the study on the development of new BIO-plastic materials based on water soluble bio-based polymer by means of direct mixing of the bio-polymers with a plasticizer and eventually, a thermal and moulding process which shapes the materials and gives them suitable mechanical properties to be used as substitutive materials of synthetic polymers in certain applications biodegradable plastics (bio-plastics) as green and sustainable alternative to conventional plastics. Detailed description and justification of various aspects of manufacturing of bio-plastics are presented alongside with some possible implications study. Subsequently, this research reveals our aim and specific objectives of the study, followed by a brief account its limitations before our concluding remarks.
1.1 Current and Future Development Currently, research on redesign of plastics and developments in biodegradable plastics are initiative taken to overcome the waste problem resulted from the usage of conventional petro-plastics. The implications of redesign and increase use of biodegradable plastics are able to maximise benefits and minimise risks. The redesign of plastic products can occur at a chemical level and a product level. Bio-based (or bio-sourced) plastics use polymers produced from renewable sources. Since traditional plastics use petroleum, substitution by bio-based plastics can potentially reduce fossil fuel use. There are four main categories of bio-based plastics:
a) Starch-based bio-plastics Manufacture from either raw or modified starch (e.g.thermoplastic starch or TPS) or from the fermentation of starch-derived sugars (e.g.polylactic acid or PLA). Common starch sources include maize, wheat, potatoes and cassava. 1
b) Cellulose-based bio-plastics Typical chemically-modified plant cellulose materials such as cellulose acetate (CA). Common cellulose sources include wood pulp, hemp and cotton.
c) Lignin-based bio-plastics Contain wood (or lignocellulosic plant material) produced as a byproduct of the paper milling industry.
d) Plant proteins Maize ‘zein’ can also be used to manufacture bio-plastics. Redesign can also occur at the level of the product. This can be with the purpose of using less plastic material or to improve a product’s capacity for recycling and re-use.
In future, bio-plastics may be more widely used for general food packaging and may also form major components in electronics housings and vehicles. Bio-plastics could also be used in more sophisticated applications such as medicine delivery systems and chemical microencapsulation. They may also replace petrochemical- based adhesives and polymer coatings. However, the plastics market is complex, highly refined and manufacturers are very selective with regard to the specific functionality and cost of plastic resins. For bio-plastics to make market grounds they will need to be more cost competitive and provide functional properties that manufacturers require.
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1.2 Problem Statement/ Issues “Utilization of conventional petro-plastics leads to a lot of environmental problems” “Bio-plastics are less familiar and popular among the consumer” “The technology to produce bio-plastics on a large scale and have similar properties as petro-plastics is still in its infancy”
The above are some common statements made by researchers concerning bio-plastic, which is the one of the green and sustainable alternative reducing the dependence and consumption of petrochemical feedstock and diminishing environmental pollution. As it is reported, in year 2009, around 230 million tonnes of plastic were produced; around 25 per cent of these plastics were used in the EU (Mudgalet al., 2010). About 50 per cent of plastic is used for single-use disposable applications, such as packaging, agricultural films and disposable consumer items (Hopewell et al., 2009). Plastics consume approximately 8 per cent of world oil production: 4 per cent as raw material for plastics and 3-4 per cent as energy for manufacture (Hopewell et al., 2009).
Bio-plastics make up only 0.1 to 0.2 per cent of total EU plastics (Mudgalet al., 2010). Majority of the consumers are not aware and understanding the significant of using bio-plastics to environment issues. Although significant research and product development has been done with biodegradable plastics, there is debate as to whether they actually degrade in natural habitats rather than under experimental conditions, particularly if they are present in large amounts (Song et al., 2009; Cho et al., 2011). There is also doubt as to whether they will degrade in the marine environment where heat and pressure conditions are significantly different (Thompson &O‟Brine, 2010). Little is known about the effect of location, soil conditions and microorganisms on biodegradation. Lacking of clear certification and label confused the public’s understanding toward biodegradable plastics.
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Current research and development (R&D) bio-plastics industries focus on redesigning of plastic products and the petrochemical-based is substituted by bio-based plastics to reduce fossil fuel use. However there are limitations in term of plastic properties such strength and durability compared to conventional plastics. Development of bioplastics limits to industries manufacturing, green and sustainable alternatives could be enhanced if the public could start making their own bio-plastic at home by the means of mixing water soluble bio-based polymer with a plasticizer, glycerol and active agent, and, eventually, a thermal and moulding process which shapes the materials and gives them suitable mechanical properties to be used as substitutive materials of synthetic polymers in certain applications.
1.3 Objective of the Study This study is designed to develop a homemade bio-plastic which is a new and simple way of bio-plastic based materials production without undergoes complicated industrial processes for households’ usage. It is also attempt to work out the formula or recipe for homemade gelatine or starch bio-plastic products. The objective can be further divided as follow: i. To come out with a bio-plastic from starch ii. To study the formulation for bio-plastics production, iii. To examine the effect of plasticizer and how it affect the quality iv. To determine the factor that affects the degradation of bio-plastics products.
1.4 Significance of the Study Development of bio-plastics is very crucial in recent years as to find out the alternative for petrochemical plastics that are non-biodegradable and give harm to environment. From this research, the production of bio-plastics perhaps can be the alternative material that can be used to replace the conventional one, with the quality 4
that can be easily degradable, environmental friendly, low cost and low energy requirement in the production. To have the potential to be commercialized, the bioplastics have to meet the certain quality that require the plastics to have such properties as biodegradable, good strength and durability, water and heat resistance and other requirement that meet commercial needs.
1.5 Scope of Study This case study is focusing on the formulation to make homemade starch bio-plastic products. Few numbers of experiments will be conducted to work out the formula for the best bio-plastics that have the best quality. The ingredients are formulized based on the required properties such as elastomeric, flexibility, strength and durability. All the works and experiments are conducted in the Chemical Engineering Technology Laboratory (MTKK) of Faculty of Engineering Technology (FTK) located at the first floor of the Faculty of Civil Engineering and Environment (FKAAS) building in University Tun Hussein Onn (UTHM).
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CHAPTER 2 LITERATURE REVIEW A plastic is widely used in the world. They are usually synthetic, most commonly derived from petrochemicals, but many are partially natural. Plastic have been known to cause a lot of environmental damage. A single plastic can take up to 1000 years to decay completely. This makes the plastic stay in environments longer, in turn leading to great build-up on the natural landscape In other words, the more plastic use, the greater the chances of environmental damage. One of the main disadvantages of plastic is that they are not renewable. The reason behind this is that they are made of petrochemicals, a non-renewable source of energy. They can be recycled, but not as easily as paper bags. Nowadays, scientist tries to create a plastic from biodegradable materials. This plastic is known as bioplastic. Bioplastics are defined as biodegradable plastics whose components are derived entirely or almost entirely from renewable raw materials. Biodegradable polymers are a form of plastic derived from renewable biomass sources such as starch rather than fossil fuel plastics which are derived from petroleum. The main component of bioplastic is starch. Starches are important constituents of paper and cardboard, binding to cellulose fibres to strengthen the final product. They are also used for their binding properties in textiles. Surprisingly, starches are also used in numerous construction products for their binding and thickening properties, such as plasterboard, glues, joint compounds, paints, foams, and ceiling coatings. Starches are important components of bioplastics. One example already in commercial production is starch-based packing foam, which replaces petroleum-based Styrofoam packing peanuts. Starches have binding and stabilizing properties that make them useful in numerous chemical products. For example, they are used in pharmaceuticals, agrochemicals, and other products as binders, coaters, flocculants, coagulants, 6
finishing agents and stabilizers. Starches are also used as fermentation substrates for the production of various chemicals. Products include pharmaceuticals, glucose, biopolymers, and “platform chemicals” like lactic acid which are used as building blocks in the chemicals industry. Scientists are hard at work developing bio–based, compostable plastics which are made from renewable feedstock and can break back down into organic matter. What’s missing is an emphasis on perennial, non-destructively harvested feedstock, especially non-food crops. Bioplastics can be made from cellulose, starch, oils, resins, and other plant and animal–based materials. Interestingly bioplastics are not necessarily biodegradable, nor is their production necessarily non-toxic. Scientists are working to emphasize non-toxic production and full compo stability and have developed many products that meet those needs. Some compostable bioplastics are already in the marketplace. Some are simple and based on starch are corn starch and tapioca starch. Some longer–lived bioplastics can be created by fermenting starches and other biomaterials. These include polyhydroxyvalerate (PHBV), a rather promising new material. Several other bioplastics are getting more attention including some based on polymerized resins like polylactic acid-based (PLA) plastics. Bioplastics are not just one single substance, they comprise of a whole family of materials with differing properties and applications. According to European Bioplastics are plastic material is defined as bioplastic if it is either bio-based, biodegradable, or feature both properties. Bio-based mean the material or product is derived from the biomass (plant). Biomass used for plastics stem from e.g. corn, sugarcane, or cellulose. The biodegradation is a chemical process during which microorganisms that are available in the environment convert materials into natural substances such as water, carbon dioxide and compost. The properties of biodegradation does not depend on the resource basis of a material, but is rather linked to its chemical structure. In other word, 100 percent fossil based plastics may be non-biodegradable and 100 percent fossil based plastics can biodegrade. The family of bioplastics is roughly divided into three main groups:
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1.
Bio-based or partly bio-based non-biodegradable plastic such as bio-based PE,
PP, or PET and bio-based technical performance polymer such as PTT or TPC-ET 2.
Plastics that is both bio-based and biodegradable such as PLA and PHA or
PBS 3.
Plastics that are based on fossil resources and are biodegradable such as
PBAT. Bioplastics is a relatively new area of research into substances that look and act like traditional plastics, but are made from plant materials. There are some examples of bioplastics: 1.
Polylactic acid (PLA) plastic: PLA is the most common type of bioplastic
currently available. It's made from starch and is typically found in disposable cups and biodegradable food-service trays. 2.
Polyhydroxyalkanoate (PHA) plastic: PHAs also use starch -- usually from
corn, beet root or sugarcane. But instead of disposable food trays, it's typically used for things like cosmetics bottles. 3.
Cellulose-based plastic: This type of plastic is made from cellulose, the
primary component in plant tissue.
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CHAPTER 3 METHODOLOGY Our study comprises mainly two parts. The first part is to convert soluble biopolymers to bioplastics usingsuitable green plasticizers like glycerol and sorbitol. The second part is the testing techniques included both physical and mechanical tests. 3.1 Materials Tapioca starch flour, glycerine (glycerol), Sodium hydroxide NaOH, distilled water, shellac, cooking oil and edible agar. 3.2 Apparatus Hot plate, electronic balance, 50ml, 20ml beakers, spatula, moulding plates, oven and 100ml, 50ml, 10ml measuring cylinder, spatula, stirrer. 3.3Making Process Bioplastics are biodegradable plastics whose components are derived from renewable raw materials. Ingeneral, they can be prepared by the following equation:
Biopolymer(s) + plasticizer(s) + other additive(s) = BIOPLASTIC
Making bioplastics from soluble biopolymers:
Various types of bioplastics can be made using polysaccharides – starch, agar or protein – gelatin. Glycerol and sorbitol are used as plasticizers. It is possible to vary the recipe in order to produce bioplastics with slightly different properties.
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First, a standard solution of 1% glycerol solution was made. Next, a suitable amount of biopolymer(s)and plasticizer(s) was added according to the amount specified in the recipe.
Then, the mixture was heated until just below boiling (95℃) with continuous stirring. Heating was stopped when froth appeared and the froth was removed. Afterwards, the mixture was allowed to cool down and transferred to a measuring cylinder. About 4050 ml mixture was poured on a white tile covered with plastic wrap by means of a glass rod. The plastics was set and dried in air. It was then totally dried by an oven before the film was taken out.
3.3.1 Procedure making the plastic film 1.
Using 20ml beaker, measure 6.25g of tapioca starch flour.
2.
Measure 50ml distilled water.
3.
Measure 1ml glycerol.
4.
Measure 10ml NaOH
5.
Mix the starch, distilled water, glycerol and NaOH in 50ml beaker. Stir all the
mixture until dissolved. 6.
Set up the hot plate and set the temperature to 100oC
7.
Place the beaker onto the hot plate and stir continuously until the mixture
become sticky, viscous and transparent. 8.
Remove the beaker from heat and pour the mixture on the moulding plate.
9.
Leave the sample in the room temperature to dry.
10.
Repeat the step 1 to 9 with different amount of glycerol. The ratio for the
formulation as shown in table below. Table 1: Ratio for Bioplastics formulation
Sample
Amount of the material Starch (g)
Glycerol (ml)
Distilled water (ml)
NaOH (ml)
A
6.25
1.0
50
10
B
6.25
1.5
50
10 10
C
6.25
2.0
50
10
D
6.25
2.5
50
10
E
6.25
2.5
50
0
3.4
Testing Techniques
3.4.1 Water Absorption ASTM D570 (Water Absorption 1 Hour/Equilibrium ASTM D570) Scope: Water absorption is used to determine the amount of water absorbed under specified conditions. Factors affecting water absorption include: type of plastic, additives used, temperature and length of exposure. Test Procedure: For the water absorption test, the specimens are dried in the room temperature for a specified time and temperature and then cool. Immediately upon cooling the specimens are weighed. The material is then emerged in water at agreed upon conditions, often 24°C room temperature for 1 hour or until equilibrium. Specimens are removed, patted dry with a lint free cloth, and weighed. Specimen size: 4 specimen strip with average dimension of 120mm X 15mm X 1mm (Long X Width X Thickness) with average weight of 0.748g Data: Water absorption is expressed as increase in weight percent. Percent Water Absorption = [(Wet weight - Dry weight)/ Dry weight] x 100 Wet weight is the maximum weight of water absorption. Equipment and Material Used: 11
Mettler Balance, Steel Tray, Tap Water
3.4.2 Comparison of Bio-Plastics and Petrochemical Plastics (Ash Content and Soot)
Scope: An Ash test is used to determine if a material is filled. The test will identify the total filler content. It cannot identify individual percentages in multi-filled materials without additional test procedures being performed. An ash test cannot be used to determine the percent carbon fiber or percent carbon black since carbon burns off during the Ash test. Also to differentiate the burning properties of bio-plastic and petrochemical plastics.
Procedure: An Ash test involves taking a known amount of sample, burning away the polymer in an air atmosphere and observes the soot and the product after burning. Ash residue is considered filler unless the residue is less than 1%. Residues of less than 1% are typically the result of additives that did not burn off.
Data: During the burning of the plastics, observe and recorded the differences of soot, colour of flame, odour and any quality that result from the process. The shape and residue of the sample after the process also need to be taken in consideration.
Specimen size: A known sample of plastics which is from petrochemical plastics and the starch-based plastics is used.
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CHAPTER 4 RESULT AND DISCUSSION 4.2 Result of Testing 4.2.1 Result Water Absorption ASTM D570 Table 2: Result of Water Absorption
Time (min) Sample (g) Strip A Strip B Strip C Strip D
Strip A B C D
0
10
20
30
40
50
60
0.762 0.771 0.749 0.758
1.164 1.115 1.140 1.132
1.209 1.284 1.23 1.25
1.268 1.296 1.281 1.297
1.268 1.296 1.279 1.295
1.163 1.105 1.183 1.184
1.141 1.025 1.069 1.129
Starch (g) 6.25 6.25 6.25 6.25
Amount of the material Distilled water Glycerol (ml) (ml) 1.0 50 1.5 50 2.0 50 2.5 50
NaOH (ml) 10 10 10 10
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Graph of Weight versus Time 1.4
1.3
Weight (g)
1.2
1.1
Strip A Strip B
1
Strip C Strip D
0.9
0.8
0.7 0
10
20
30
40
50
60
Time (min) Graph 1: Graph of Weight of water absorb vs time
Calculation Percent Water Absorption =
Wet weight−Dry weight Dry weight
x 100
Wet weight is the weight of the plastics at the constant reading (maximum water absorption) .From the result, the constant reading at the time of 30 and 40 minutes.
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Strip A 𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑊𝑎𝑡𝑒𝑟 𝐴𝑏𝑠𝑜𝑟𝑝𝑡𝑖𝑜𝑛 =
1.268 − 0.762 𝑥 100 = 66.4% 0.762
Strip C
𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑊𝑎𝑡𝑒𝑟 𝐴𝑏𝑠𝑜𝑟𝑝𝑡𝑖𝑜𝑛 =
1.296 − 0.771 𝑥 100 = 68.09% 0.771
Strip D
𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑊𝑎𝑡𝑒𝑟 𝐴𝑏𝑠𝑜𝑟𝑝𝑡𝑖𝑜𝑛 =
1.281 − 0.749 𝑥 100 = 71.03% 0.749
𝑃𝑒𝑟𝑐𝑒𝑛𝑡 𝑊𝑎𝑡𝑒𝑟 𝐴𝑏𝑠𝑜𝑟𝑝𝑡𝑖𝑜𝑛 =
1.297 − 0.758 𝑥 100 = 71.11% 0.758
Strip B
100
Graph of Water Absorption (%)
90 80
Water Absorption (%)
70
66.4
68.09
71.03
60
71.11
Strip A
50
Strip B Strip C
40
Strip D
30 20 10 0
Type of Strip
Graph 2: Graph of water absorption rate (%) for each plastics strip
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4.2.2 Comparison of Bio-Plastics and Petrochemical Plastics (Ash Content and Soot)
Table 3: The differences of Bioplastics and Petrochemical Plastics
Aspects
Bio-Plastic
Conventional Plastic
Soot Colour
White
Black
Smell
Smell like burning of wood
Pungent , Petroleum like smell
End Product of Combustion
Ashes
Harden black plate object
Combustion efficiency
Difficult to burn
Easy to catch fire
4.2.2.1 How Bio-Plastic Different from Petroleum Based Plastic? Recent years, there are many so called “biodegradable” plastic used by most of the supermarket, hypermarket and etc. As a consumer, we have to alert that no all the “biodegradable” plastics are bio-plastic. Based on the research done by Naturework, these types of plastics are known as oxo-biodegradable plastic. Oxo-biodegradable plastic is conventional polyolefin plastic (petrochemical) to which has been added small amounts of non-toxic metal salts. At the end of the useful life of the product these salts catalyse the natural degradation process in the presence of oxygen to speed up the molecular breakdown of the polyolefins. The chemical change results in a material with a completely different molecular structure. The process continues until it is no longer a plastic, eventually becoming available for biodegradation by microorganisms. Finally the material assimilates into the environment as carbon dioxide, water and biomass. Throughout the research and experiments done, our team have better understanding on bio-plastic and would like to suggest an easier way to differentiate both plastics. In the experiment, combustion of both types of plastic gives a significant difference. From what can be observed, combustion of conventional/ petrochemical plastics resulted in black soot, dark liquid like gel (high viscosity). The combustion last long and continue to burn even the plastic has changed its structure. This can be explained that the petrochemical contain in the plastic sustain the combustion. During the combustion, a strong pungent smell released which is a smell 16
of petroleum. The end product of the combustion is the dark liquid becomes harden and forms a ‘black plate like object’. (Please Refer to Appendix Picture 1 and 3) Whereas, the combustion of bio-plastic made by our team resulted in white soot and does not give out any strong pungent smell. It is just smell like a burning of wood or dried leaves. From what can be observed, the combustion of the bio-plastic does not last long. For complete combustion of this plastic, it requires a continuous supply of heat or fire. In another words, this bio-plastic resists combustion. The end product of the combustion of this plastic is black ashes powder. (Please Refer to Appendix Picture 13 and 14)
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CHAPTER 5 CONCLUSION
5.1 Conclusion Bioplastics materials find various applications in the industrial sector due the degree of various industrial products that can be derived from these materials. Bioplastics products derived from starch materials finds more application than any other renewable resources. This is because of its various properties suits the current market, economy and environment impacts. They have a biodegradation ratio close to cellulose, with their mechanical characteristics related to traditional plastics. The study has also found out that food packaging sector does not employ bioplastics materials extensively because of the following reasons. The high prices involved may reduce the market base for such products. Bioplastics may have non ideal water characteristics, meaning that they may allow infinitesimal amounts of water to permeate through. Research works have not been done extensively to indicate the level of food contamination while packaged in these packages. Some food products have chemicals that could react or interact with elements in the packaging containers leading to contamination or formation of toxic products.It is however important to note that bioplastics products are used in food packaging in such areas as food service ware items. Fundamental research on the extent of interaction between bioplastics products and food products could enhance their application in the food packaging sector. However the previous bioplasticability wasapplied on food packaging is limited on production thus this project are carried out to perform various production as discussed above. In addition, this bioplasticshas accomplished several Principles of Green Chemistry for instant, bioplastics is safer compared to petroleum based plastics because bioplastics have been evaluated and found to reduce 30-80% of Green House Gas Emission that one would obtain from normal plastics. They facilitate the reduction of emission of carbon dioxide (CO 2 ). Over the years the prices of oil has been rising. This has been triggering plastic prices. Due to the increased concern on the fuel shortages, products that consume less fuel in their production and use have increasingly become of great importance in the industrial sector. Bio plastics are 18
cheaper to produce hence the need of the world to employ more resources in utilizing these technologies. When compared to ordinary plastics, the production process of bioplastics uses minimal fossil fuel; meaning that they are less dependent on petroleum fuel. Bio products at the same time reduces the quantity of toxic run-off that is generated by oil based products. Furthermore, their biodegradable characteristic facilitates decomposition process and hence reduces on the quantity of wastes from the society today. This means they are environmental friendly reducing environmental pollution. This characteristic helps to make the management of waste less time consuming and economical. They have thus been incorporated in the production of packaging materials used in supermarkets among other sectors in the food industry. The use of bioplastics products in industries helps to reduce exposure of harmful elements such as trace metals. They also have a high processbility. Bioplastics products are derived from renewable resources unlike the oil based plastics. They also have better mechanical processes as compared to oil based plastics. Moreover, materials used to make bioplastics are less hazardous. The crystalline nature of starch allows it to be destroyed by heat; this means that it can be destructurized and thus can undergo modification to help it attain properties used to make various bioplastics products. This facilitates the production of materials that are of high heat resistant properties, and hence used in industrial processing and compression processes. When starch have undergone destructurization process, they attain thermoplastic properties and are treated, if need be, as traditional plastics. Thus, undeniable that bioplastic are very convenient to be used nowadays for various productions.
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5.2 Recommendations Recommendation was made based on the inaccuracy of results obtained from the test conducted. From the test, the plastic produced possessed several weaknesses. Some of the weaknesses are formation of bubble, brittle plastic and faster rate of water absorption. Recommendation was made to improve the properties of plastic produced. 1.
In order to avoid bubbles in the plastic, one must stir the mixture gently
throughout the process until clear solution was obtained. Avoid using magnetic stirrer as it will mix the solution vigorously and formed more bubble. 2.
The plastic formed takes a longer time to dry. The thickness of plastic will
affect the time taken for the sample to dry. Therefore, to avoid this problem, the recipe needs to be looked especially the amount of plasticizer used. The recipe required using glycerine solution that is 1% glycerin (in other words: 1 part glycerin mixed with 99 parts water). If the glycerin solution too strong (too concentrated), then the bio plastic may end up being overly flexible, or may even stay "gooey" without ever drying completely. So it might be worth reviewing the recipe used, or even trying again with a lower amount of plasticizer (such as glycerin). 3.
To improve the strength of bioplastic, plasticizer was added. Though glycerol
was added to increase the strength, the plastic still brittle and easily break. The degree of stretching is low compared to fuel-based plastic. Water is known as the most excellent plasticizers for starch but additional plasticizers were recommended to be added so that the plastic become less brittle and more flexible. 4.
During moulding process, it was difficult to spread the mixture onto the
surface of the plate. What happened is that, the mixture was placed between 2 layers of plastic cardboard and was dried for overnight. However, it turns out that the mixture still not dried. We recommend to spread the mixture single layer on the cardboard. Thin layer of plastic will be produced and shorter time was needed to dry the plastic.
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5.3 Limitations and Solutions Bio plastics are an increasingly well-known alternative to petroleum-based plastics. In making of the bio plastics, there are some limitations that bring disadvantages in the product. The bio plastic that we created is from the mixture of starch, glycerol, distilled water and sodium hydroxide (NaOH) where we fixed the amount of starch, glycerol and NaOH. By changing the composition of glycerol, we found out that the least amount of it gives the lowest percentage of water absorbance. We know that a plastic that is created must have waterproof properties so that it can be utilized to its fullest. From the water absorbance test, our bio plastic can only withstand a certain amount of water before it disintegrates. This is one of our limitation and we try to overcome it by coating it with a waterproof layer such as shellac.Furthermore, in spreading the mixture of the bio plastic, we have a hard time trying to spread it with equal pressure to produce a perfect layer of the biodegradable plastic. In order to achieve it, we try to apply an equal pressure by putting a load on top of the layer. Moreover, this same problem also applies in moulding of the bio plastic. This particular limitation is something that we cannot overcome as we do not have the access towards the suitable equipment. Other than that, we do not manage to know the suitable temperature in drying the mixture of the bio plastic in order for it to become completely solid. When the bio plastic is dried, cautious measures need to be taken in peeling off the solid bio plastic in order to avoid it from rupturing. In terms of tensile strength, the bio plastic that we made from the mixture is quite weak and this is due to the layer that we made which is very thin. If the layer is much thicker, then the tensile strength of the bio plastic would be greater. Even though the plastic is weak in strength, it is flexible which shows that it is easy to be mould in the way we want it. Besides that, the bio plastic cannot withstand temperature that is very high such as 140 ºF as it would melt. This shows that the bio plastic can only be made for the usage and application that does not exposed the plastic to a high temperature. Hence, most of our limitations of bio plastic can be overcome and this proves that it can be just as good as the petroleum-based plastic. 21
REFERENCES 1. Chen, G. , & Patel, M. (2012). Plastics derived from biological sources: Present and future: P technical and environmental review. Chemical Reviews, 112(4), 2082-2099. 2. Dr-Ing Michael Thielen. 2012. Bioplastics – Basics Applications Markets. Polymedia Publisher GmbH, First edition. 3. Reddy R.L et.al. Study of Bio-plastics As Green & Sustainable Alternative to Plastics. International Journal of Emerging Technology and Advanced Engineering. Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 3, Issue 5, May 2013) 4. Abou-Zeid, D. M., Muller, R. J. and Deckwer, W. D., Journal of Biotechnology, 86, 113 (2001). 5. Oakley P. Reducing the water absorption of thermoplastic starch processed by extrusion. Master of Applied Science thesis. Department of Chemical Engineering and Applied Chemistry University of Toronto. 2010 6. Farayde M.F et.al Development of flexible bioplastics from cassava starch and glycerol using thermoplastics extrusion. University of Londrina, Brazil. 7. W Affo, N.Y Samuel et.al. Development of Cassava Bioplastics for Consumer Packaging. African Journal. 2012 8. Testlopedia
-
The
Plastics
Testing
Encyclopedia
(retrieved
from http://www.intertek.com/polymers/testlopedia/ on 20 May 2014) 9. Water
Absorption
ASTM
D570
(retrieved
from http://www.intertek.com/polymers/testlopedia/water-absorption-astm-d570/ on 20 May 2014) 10. Ash
Content
ASTM
D2584,
D5630,
ISO
3451
(retrieved
from http://www.intertek.com/polymers/testlopedia/ash-content-analysis/ on 20 May 2014) 11. Bioplastics (retrieved from http://en.wikipedia.org/wiki/Bioplastic on 19 April 2014)
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APPENDIX MATERIAL, APPARATUS AND PROCEDURE OF BIOPLASTICS PRODUCTION
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Figure 1: The cassava flours us as the source of starch.
Figure 2: Glycerol use as the plasticizer
Figure 3: The apparatus used, beaker, measuring cylinder, hot plate, etc.
Figure 4: The flour was weight using electronic balance.
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Figure 5: Starch, glycerol, distilled water, NaOH was added and stir to mix well.
Figure 6: Put the mixture on the hot plate at 100oC and continuously stir until the mixture become sticky and transparent
Figure 7: After the mixture turn stick and transparent, transfer the mixture into mould
Figure 8: The mixture was left to cool for days.
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Figure 9: The BioPlastics
Figure 10: The plastics sample cut into strips and soaked in distilled water.
Figure 11: After 10 minutes, each strip is wipe and weighed.
Figure 12: The bioPlastics rupture after too long in water.
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Figure 13: Combustion of Conventional Plastics
Figure 14: Combustion of BioPlastics
Figure 15: End Product of combustion
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