Castor oil smoothes polymer development

Fujitsu has developed a flexible biopolymer using castor oil, which could be used for small components of notebook PCs and mobile phones, such as connector covers.



In 2002 Fujitsu started using bio-based polymers based on polylactic acid, made from materials including corn, in the chassis of the FMV-BIBLO notebook PC. However, in order for plant-based materials to be used more widely in Fujitsu products, the company needed to develop a new bio-based polymer with a higher bio-content and superior flexibility which is suitable for mass-production.



To address this need, Fujitsu worked with French chemical company Arkema, and succeeded in developing a new bio-based polymer plastic that has as its principal component polyamide-11 (PA-11), which is derived from castor oil.



By weakening the interaction of the chain molecule in PA-11 and relaxing the stereo-regularity of their organisation, the resulting new material has increased flexibility. This means it can withstand repeated bending without causing the whitening that often occurs when such materials are strained.



Fujitsu has also succeeded in developing prototype notebook PC cover components with a high bio-content of 60-80 per cent. Even after adding high-density fillers to increase strength, the polymer maintains good impact-resistance, meaning the material could eventually be used in PC chassis and other larger components.



Fujitsu plans to continue research of bio-based polymers derived from castor oil and consider using such polymers in small components for notebook PCs and mobile phones by 2008. It will also look for ways to apply them to larger components as a way to further reduce environmental impact.