Melt-away plastics

Date : June 2 2009
Source : The Star
Title : Melt-away plastics

By WONG LI ZA

Here’s something to look forward to – plastic bags that dissolve in water. IF YOU have been feeling guilty using all those plastic bags for your groceries, a green solution is at hand. A team of seven researchers from Universiti Teknologi Petronas (UTP) has invented an award-winning material called Greenphylic Water-Soluble Degradable Plastic, a polymer similar to plastic that dilutes in water.

Led by electrical and electronic engineering lecturer Prof Dr Ramiah Jegatheesan, the team comprised Hossam Mahmoud Gamal Eldin, Mohammad Faizal Che Daud, Nor Hidayah Usop, Noordiana Khalil, Mohd Anuar Sulaiman and Ahmad Ridhwan Hassan.

The project was awarded the Gold Medal at the 19th International Invention, Innovation and Technology Exhibition last May. It also received three special awards – Best Invention for Universities/Research Institutes, World Intellectual Property Organisation Best Invention Award and KASS International (a Malaysian intellectual property firm) Best Invention Award.
In November, the project garnered international glory by winning the Gold Medal at the Belgian and International Trade Fair for Technological Innovation in Brussels.

The project was exhibited under the name Eco Plast, short for “eco-friendly plastic-like material”. Winning the latest award has heightened the material’s potential for commercialisation, according to Ramiah, 68.

Plastic bags are harmful as they take a long time to degrade. And once broken into molecular materials, they can contaminate the soil and water tables. Ramiah said when burnt, plastics produce hazardous gases which can cause serious health problems. In addition, discarded plastics can clog water and sewerage pipes.

“Bearing these in mind, usage of plastic bags is banned in several countries,” he said. Eco Plast consists of a synthetic polymer material made from polyvinyl alcohol (PVA). According to Encyclopaedia Britannica, polyvinyl alcohol is a colourless, water-soluble, flammable resin belonging to the family of organic polymers. It is derived from a vinyl polymer.

The resin is used in sizing agents that confer resistance to oils and greases upon paper and textiles, to make films resistant to attack by solvents or oxygen, as a component of adhesives and emulsifiers, and as a starting material for the preparation of other resins.

“Polyvinyl alcohol is a water-soluble synthetic polymer which has excellent film forming, emulsifying and adhesive properties. It is odourless and non-toxic, has high tensile strength and flexibility as well as high oxygen and aroma barrier. However, these properties are dependent on humidity. With higher humidity, more water is absorbed. The water, which acts as a plasticiser, will then reduce its tensile strength, but increase its elongation and tear strength,” explained Ramiah.

Eco Plast can dissolve in water at normal room temperatures of between 25°C and 35°C. If the water is heated, the dissolving time reduces considerably.

In normal thickness, Eco Plast dissolves in water in 60 minutes when the water temperature is around 25°C. It will dissolve in 15 minutes if the water temperature is 40°C. If the water temperature is increased to 50°C, the dissolving time will be around five minutes.

According to Ramiah, water that is used to dissolve Eco Plast will not contain any toxic eleme

nts and thus no harmful effect to living beings or the environment will occur. This water can be disposed of via the kitchen sink as normal waste water.

He added that Eco Plast can be used to manufacture carrier bags that are useful for grocery items, to pack medical pills, produce gloves and for packaging of other substances.

At present, Eco Plast is two to three times costlier to produce compared to plastic.

“Once it is commercialised and manufactured on a large scale, the cost will reduce substantially. Furthermore, (it must be highlighted that) no cost is involved in disposing of this material. We have filed for patent and are currently in the process of commerciali­sing the product,” he said.