Chemical composition and molecular structure of fibers from transgenic flax producing polyhydroxybutyrate, and mechanical properties and platelet aggregation of composite materials containing these fibers

In order to improve the properties of flax fibers so that they interact better with the matrix material in composites, several lines of transgenic flax were produced over-expressing the bacterial polyhydroxybutyrate (PHB) synthesis genes. Infra-red spectrophotometry revealed that the cellulose in fibers from the transgenic plants was more highly structured than in fibers from the control plants and PHB was strongly bound to the cellulose of the fibers by covalent ester and hydrogen bonds. The composite containing fibers from transgenic plants was significantly stronger and stiffer than the composites containing fibers from the control plants. Scanning electron microscopy of the fracture surface of composite sheets indicated that fibers from transgenic plants adhered to the polypropylene matrix significantly better. The composite containing fibers from transgenic plants induced almost no platelet aggregation and so may therefore be useful in the construction of biomedical devices that come in contact with blood.