Synthesis of Bio-based Polymer Composites: Fabrication, Fillers, Properties, and Challenges

The bio-based polymer composite industry is growing dramatically following economic and environmental concerns over constant use and dependence on non-renewable feedstock, such as crude oil. It is notorious that there has been a continuous increase in the research activity related to the development of novel bio-based materials over the past couple of decades. The focus has slowly shifted from simpler systems, consisting primarily of traditional thermoplastics reinforced with natural fibers, to more advanced composites with carefully engineered bio-based matrices, or fully bio-based materials in which both matrix and reinforcement are of bio-based origins. In the realm of bio-based biomedical applications, the efforts are vastly dominated by investigation of PLA and PLA-based composites. The existing challenges for the fabrication and the use of bio-based composites are mainly associated with the lack of consistency in materials’ characterization among the various proposed systems, which makes a direct comparison of different materials exceedingly hard. This manuscript contemplates the fabrication of bio-based composites through a processing perspective, and by also covering the literature of the many resin/reinforcement systems investigated to date, before concluding with brief remarks on the desired properties and challenges related to the use of bio-based composites in biomedical applications.