Biomedical applications copolymer composites

By introducing DXO units into the backbone of PLA, the Tg of the lactides may be lowered to or below body temperature, and the crystallinity may be lowered. Thus, more flexible materials are obtained where the properties and degradation rate can be varied over a broad range by means of the composition. This is interesting for biomedical applications. Blends of PLA and PDXO provide additional opportunities to vary the properties. There is a large difference in reactivity ratio of LA and DXO [154]. As a result, a more block-like copolymer structure than expected for a totally random copolymer is obtained, even though the structure is somewhat randomized by transesterification reactions. In contrast, DXO and e-CL form a truly random copolymer [156]. Tri-block copolymers of LA and DXO have recently been described [303]. 

Filament wound flat strip composites of PE fibie-rrinforced ethylene-butane copolymer have been used for diff oit biomedical applications. Composites of three difierent matrix compositions and two winding angles were reported. The matrix composition varied with the copolymer ratio raidering the composite material softening and it is more compliant and suitable for different biomedical application [75]. 

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