Issues related with plastic bags
(Williamson,2003) has stated that since the introduction of plastic in 1977, it has been widely used by people in the industrialized country. Countless numbers of bags filling landfills and spilling over every surface of the Earth (Chauhan, 2003; Thiel et al., 2003). This is because the plastics are used only once and get disposed after that. Although petroleum based plastic is not biodegradable, it will break down to smaller pieces and releases toxic chemicals into the soil and the ocean, resulting in health dangers such as neurological problems and cancer.Plastic bags are often mistaken for food by animals, leading to suffocation or blockage of digestive tract, and eventually death. South Africa, Kenya, Somaliland, and India are four nations that report high levels of these problems, with as many as 100 cows dying per day in India (World Watch, 2004; Edwards, 2000). Plastic bags are found almost everywhere, from rural areas to urban areas. Plastics can accumulate in the drain pipes, contributing to flooding. Beside that, It also creates stagnant water, this creates the ideal habitat for mosquitoes and other parasites to reproduce, this increases the risk of contracting a disease.
What to do with biodegradable plastics when they become waste
Both biodegradable plastics and compostable plastics will break down naturally, but it need a long time for that to happen. Before that happen, they are no different from the other pollutant, it is a threat to all the living things and pollute the environment. It requires high temperature for it to decompose, therefore it takes much longer time to decay naturally. Under the conditions of industrial process, the biodegradable plastics will decompose much faster, this is why we shouldn’t simply dispose the plastics.
Advantages of degradable plastics and starch-based plastics
Degradable plastics
Bioplastics
They are light and have strong physical properties
They do not cause pollution to the environment
Can act as an insulator in many appliances
They are made from renewable resources, so precious resources are not used.
They are malleable and can be hammered to different shape
It requires lesser energy to be produced
Disadvantages of degradable plastics and starch-based plastics
Degradable plastics
Bioplastics
They are made from non-renewable resources thus making them not environmental friendly
They don’t last long and will decay very quickly
They release toxic chemicals when they are burned which will affect our health
They show weaker physical properties compared to degradable plastics
They are often mistaken for food by animals. The plastics does not decompose and get trapped in the animal’s stomach
Starch-based plastics are made from plants, with already increasing demand of food supply, plastics production from plant can creates competition for food sources
Methodology
Extraction of starch from potato tubers
Some important steps have to be followed before the extraction of the starch from the potato tubers.
1. Weighing
2. Washing
3. Weighing v2
4. Peeling
5. Dicing
6. Blending
7. Filtration
8. Drying
Weighing
Select a potato with an appropriate mass. Weigh it to obtain an initial mass of the tuber. Potato tubers with a total weight of approximately one kilogram were used in the extraction in order to get the best result. Note that the ratio of the impurities on the potato affects the weight too.The ratio of the impurities to the potato was then determined by the difference in the weighing before and after washing.
Washing
Wash the selected potato with water to remove the contaminants which could otherwise affect the final output of the tuber. Rubbing is an important step since this step will determine the purity factor of the potato. Proper washing need to be done to fully avoid any contamination.
Weighing v2
The potato is then weighed again in order to compare with the weight obtained initially, making sure that the ratio of impurities does not affect the final result.
Peeling
Peel the potato with care by using a knife in order to prevent the peeling of additional potato cells. This would cause loss of starch granule from the potato resulting in starch loss. Damaged starch granules could lead to alteration in the physiochemical properties of the starch , resulting in an undesired result.
Dicing
The peeled potato was then diced to small regular cubes of similar size .Again, care was taken to avoid damage of the starch granule in the sweet potato.
Blending
Blend the diced potato in a blender with water
Filtration
Filter the solution with a cloth (cheesecloth would be the best choice).This is to separate the starch granules extract from the residue of the potato. Your end result would be a starch solution. Redo this step to obtain more starch.
Drying
Dry the starch solution to obtain solid starch.
Production of starch based bioplastic
Procedure
1. Add 25cm^3 water into the beaker and add 2.5g potato starch, along with 3cm^3 of 0.1M hydrochloric acid and 2cm^3 of glycerol and stir it with a glass rod.
2. Place the beaker on the tripod and heat it using the Bunsen burner and boil it gently for 15 minutes.
3. Turn the Bunsen burner off after 15 minutes and leave it to cool.
4. Dip the glass rod into the mixture and apply it onto the universal indicator to measure the
pH. Add sodium hydroxide to neutralise the mixture and test it with universal indicator again.
5. Pour the mixture from the beaker into the petri dish and spread the mixture evenly.
6. Leave the petri dish for it to dry.
