Poly(lactide) is a biodegradable, biocompatible material coming from renewable resources. Such properties, added to a more and more competitive cost makes it a very interesting material for current industries. Coupled with other materials, properties can be fine tuned for different fields, ranging from construction materials to biomedical applications.
Poly(lactide) was grown on the surface of various oxide particles through ring-opening polymerization of lactide, using lactic acid as surface modifier. The aim was to determine what materials were compatible with this method to make cost-efficient materials with new properties. To this end, a simple, one-pot reaction under very mild conditions was developed and tested with various materials.
Particles containing about 40% polymer were successfully obtained from silica gel particles. Poly(lactide) growth was confirmed through Fourier-transform infrared and solid state 13C nuclear magnetic resonance analysis. Scanning electron microscopy showed a polymer growth on the particles, although it was shown part of the growth comes from the surface initiator polymerizing on its own. It was also shown that polymer did not smoothly coat the particles but rather grew in random pattern.
White quartz, basic alumina, titanium oxide and montmorillonite clay all successfully grew poly(lactide), while iron oxide, cobalt oxide, barium titanate and starch did not within the chosen reaction conditions. It is also possible to vary the monomer being used or the surface modifier, as was shown by growing poly(caprolactone) or by using glycolic acid on silica gel particles.