Evaluation of the bio-based materials utilization in shape memory polymer composites production

Shape memory polymers (SMPs) are part of the smart materials family. They have the ability to recover their permanent shape, from a temporary shape, upon application of a stimulus, such as heat, PH, etc. They are utilized in various multifunctional engineering design applications, including biomedical, aerospace, and military fields; and therefore, they are becoming increasingly popular. Some of these applications require high mechanical and shape memory properties that cannot be offered with SMP. Therefore, the use of shape memory polymer com-posites (SMPCs) has become a common practice. However, most SMPs and SMPCs are of fossil origin, and their extensive use raises environmental concerns. Consequently, in recent years, scientists and engineers started to heavily investigate bio-based shape memory polymer composites (bio-SMPCs). A comprehensive critical review investigating the bio-SMPCs is missing in the literature. Hence, in this review, we categorize bio-SMPCs under two main sections: (1) either the matrix or the reinforcement is a bio-based material, (2) both matrix and the reinforcement are bio-based materials. The critical review includes the general properties bio-SMPCs, production methods, applied tests and application areas. Finally, this review aims to guide future research by including the opportunities and challenges concerning bio-SMPCs.