New Biomass-derived PC Composite to Replace BPA-based Polycarbonates

Researchers from Korea Research Institute of Chemical Technology have made a new, tough, transparent Polycarbonate composite reinforced with two biomass derived alternatives isosorbide and cellulose nanocrystals replacing both BPA and glass fibers.

These Polycarbonate sheets have outperformed traditional BPA-reinforced polycarbonate plastic in strength tests and can replace BPA-based polycarbonates in a variety of common applications.

The research team was led by Sung Hwang, Dongyeop Oh and Jeyoung Park from the Korea Research Institute of Chemical Technology.

Safer Alternatives for BPA

Polycarbonate is a popular shatter-resistant alternative to glass in windows, display screens, bottles and optical fibers. However, polycarbonate plastics are frequently made using bisphenol A (BPA) and glass fibers.

BPA is an endocrine disruptor increasingly associated with regulations – Canada, the EU and the US Food and Drug Administration have banned BPA in baby bottles with the EU also banning BPA in food packaging – as well as health risks. And in the event of a fire, glass fibers generate fine particulates that can cause respiratory problems.

Scientists are therefore searching for safe alternative components that improve the transparency, and mechanical and thermal properties of polycarbonates like BPA and glass fibers do.

Properties of New Composite

Isosorbide already features in pharmaceuticals and cosmetics, and has a high thermal stability.

The research team first dispersed the cellulose in isosorbide and used an insitu polymerization to produce their composite. Cellulose disperses evenly throughout the material and only 0.3wt% is needed. The final material is stronger than BPA-based controls, with a tensile strength of 93MPa. The new composite was also highly transparent – transmitting 93% of light at 500nm.

‘The excellently dispersed cellulose nanocrystals minimally interfere with visible light and the synergetic interaction between the polymer and the filler reduces the microbubbles in the matrix, which can induce light scattering,’ commented Park.

Park and his colleagues attribute the synergistic interactions and high miscibility between the isosorbide and cellulose moieties to ‘the principle of like-dissolves-like’ as they are both derived from glucose and have ether linkages.

Applications of New Biomass-derived PC Composite

This Glucose derived polycarbonate plastic could be used in:

• optical fibers
• safer glazing plastics
• baby bottles

Stephen Miller, Sustainable Plastic Expert from University of Florida, said ‘the majority of bio-based polymers are interesting primarily because they are bio-based; it is the exception that they possess properties that surpass those of fossil fuel-based materials. That one polymer nanocomposite can accomplish all this is quite noteworthy.’

Source: Chemistry World