Enhanced Ductility Through Tuning Crystallinity of Chemically Recyclable Polyolefins

Recent work has established a new class of butadiene-derived chemically recyclable polyolefins based on polydivinyloligocyclobutane, or pDVOCB. Previous studies have shown that pDVOCB is highly crystalline and features high melting temperatures but suffers from brittle mechanical behavior. This work examines a family of related cyclobutane polymers which incorporate flexible spacers to achieve tunable properties, ranging from soft and elastomeric siloxane copolymers to ductile and tough methylene-modified polymers. We examine the effect of methylene spacers on the crystal-to-rotator transition experienced by cyclobutane polymers, as well as the interplay between this phase transition and polymer thermomechanical properties. Through investigation of the effects of structural modifications on the crystalline structure, phase transitions, and relaxation processes, this work provides insight into the mechanisms underlying the tunable properties in this new family of chemically recyclable polymers.