Scientists from the Newcastle University International Singapore (NUIS) have devised a way to more effectively produce bioplastics, a sustainable and potentially more cost-effective alternative to traditional plastics.
Protein-based plastics derived from natural resources have attracted increasing global interest, but the production and performance of these plastics has been fraught with challenges. Most bioplastics to date have high sensitivity to water, insufficient mechanical properties (low tensile/ultimate strength) and hence a narrow window of processing conditions (inconsistent molding conditions). NUIS scientists have moved to resolve this issue through a series of proprietary steps in the preparation of protein-based plastics and the addition of lignin – an organic polymer usually found in wood – to improve the performance of bioplastics.
Bioplastics are not only be used for sustainable disposable products such as packaging, bags, bottles and containers. They are also for non-disposable products such as carpets, casings and electro-active material, where the goal of using bioplastics is not to be biodegradable but to create items from sustainable resources such as plant and protein material. The potential positive impact of adopting bioplastics in everyday use would be significant in Singapore, in terms of both consumer goods and industrial applications. A 2013 study conducted by the Singapore Environment Council shows that Singapore uses three billion plastic bags a year.
“As an alternative to traditional plastics, bioplastics have numerous potential applications in our daily lives and in industries. For bioplastics to make market ground, they will need to be more cost-competitive and provide similar or better properties as petro-based plastics. This is a breakthrough in technology as it turns the pervasive plastic to be environmentally-friendly, and realistically helps reduce our environmental impact,” said Dr. Nasir Al-Lagtah, researcher, Newcastle University International Singapore, who leads the study.
At the moment bioplastics are mainly used in the plastic packaging market which has rigorous specifications including moisture and gas permeability. Addition of kraft lignin increases the tensile strength of protein-based plastics, which shortens molding cycle time and decreases energy consumption. Increasing tensile strength of bioplastics enhances their extrusion capabilities and now can meet the plastic packaging specifications. Moreover, the addition of Kraft lignin, which is hydrophobic, significantly reduces bioplastics water-sensitivity and therefore, improves their stiffness and rigidity. Environmentally sustainable products – from common items such as bottles, film, waste collection bags, packaging and food service-ware, to automotive parts, electronics and adhesives – can be produced.