Biodegradable and crosslinkable poly(propylene fumarate) liquid crystal polymers

In recent years, liquid crystal polymers (LCPs) have attracted extensive attention due to their widespread application in artificial muscles, engineering plastics, high-modulus fibers, etc. However, the design and fabrication of LCP materials with excellent biocompatibility, biodegradability and mechanical properties are still challenging. Here, we synthesized two poly(propylene fumarate)-backbone LCPs (PPF-LCPs) by ring opening polymerization (ROP) between two cholesterol-based epoxy monomers and maleic anhydride, and a successive isomerization process. The resulting PPF-LCPs bearing biocompatible cholesterol units exhibit good thermal stability and a highly ordered Smectic A phase. Moreover, a UV-initiated chemical crosslinking of the unsaturated PPF main chain dramatically strengthens the mechanical performance of the corresponding PPF-LCP materials. Furthermore, the in vitro degradation experiments indicate the good biodegradability of crosslinked PPF-LCP films. These novel PPF-LCPs are of potential utility as biological tissue engineering materials.