Medical fibres from lactic acid
Technical fibers make the ropes of children's swings safe or are indispensable in medical operations. The raw materials for these fibers are often petroleum-based polymers. In view of the limited availability of fossil raw materials and the plastics problem, Boris Marx of the Faserinstitut Bremen researched alternatives using biopolymers. In the process, he said, he has produced a PLA blend that enables the development of such yarns with higher strength and stiffness and the substitution of conventional plastics.
Biopolymers such as polylactide (PLA) are made from bio-based, renewable raw materials and are biodegradable, unlike conventional polymers made from petroleum. PLA is produced by chemical synthesis based on lactic acid. Commercially available PLA is processed into yarns that can currently be used for home textiles, for example.
As part of the project, Marx says he has now succeeded for the first time in producing a PLA blend with a stereocomplex crystal structure on a pilot plant scale. "In the process, two PLA starting materials were mixed in the compounding process. The special feature here is the process control at temperature. The result is a PLA blend in powder form with a stereocomplex crystal structure," explains Marx.
The simple transfer to industrial scale allows sufficient material availability. This has created the potential to develop technically industrial PLA yarns with increased strengths. This means that the areas of application for these biotechnological fibers can be significantly expanded, conventional plastics can be further replaced, and resources and the environment can be conserved accordingly.
Broad application from medical technology to aerospace
"For medical technology and especially for us as a developer and producer of innovative textile implants, the research results achieved in the project are of great importance," says Sven Orberhoffner of ITVP Denkendorf, describing the medium-sized interests of the project result. Up to now, he says, there have been no PLA-based products on the market in stereocomplex form. The blend that is now available makes it possible to develop new and innovative products such as improved osteosynthesis plates for treating fractures, he said.
According to Axel S. Herrmann, the director of the Faserinstitut Bremen, the result of the project is an innovative, highly sustainable material intended for high-tech industries such as aerospace, medical technology and automotive. "Since the material has been developed on an industry-related pilot plant, the parameters that have been researched are very easily transferable to industry. This is currently being done with the project support committee together with small and medium-sized enterprises and the WNR research association," Herrmann said.