Topological Manipulation of Fully Biobased Poly(epoxy imine): From Thermoplastic Elastomers to Covalent Adaptable Networks and Permanently Cross-Linked Networks

Fully biobased poly(epoxy imine) withtunable propertieswas achieved by manipulating the topology through reaction temperature. Tunable properties arising from variable topologies makepolymersversatile and irreplaceable in modern society. However, manipulatingthe topology of a specific polymer with a determined composition remainsa big challenge. This study aimed to propose a facile approach tomanipulate the topology of fully biobased poly(epoxy imine)s (PEIs),which were synthesized from the reaction between epoxy-derived trialdehydeprecursors (ETPs) and decamethylene diamine (DDA). PEIs with topologiesvarying from branched structures to covalent adaptable networks (CANs)and permanently cross-linked networks (PCNs) were easily obtainedby simply adjusting the reaction temperature. At a low temperature(T = 120 degrees C), partial aldehyde-amine condensationbetween ETP and DDA gave rise to a branched thermoplastic; at mediumtemperature (120 degrees C < T <= 160 degrees C),enhanced extent of aldehyde-amine condensation led to a CAN cross-linkedby imine bonds; at a high temperature (T > 160 degrees C),self-cross-linking of imine bonds occurred to result in a PCN. Withdifferent topologies, fully biobased PEIs showed different mechanical,physical, and chemical properties and thus great potential as alternativesto fossil-derived polymers in various applications.