Making transparent, super-ductile and heat-resistant semi-crystalline polymers*

Based on our recent molecular picture [1], chain networking is a key factor that affords ductility for polymer glasses during tensile deformation. Therefore, it is essential, when considering the mechanics of semicrystalline polymers, that crystallization does not disrupt the chain network, which is typically not the case for semicrystalline polymers that crystallize slowly. We explore a molecular strategy to avoid depletion by crystallization of the polymer entanglement associated with the interchain uncrossability. The present study will characterize the conditions for producing such a new crystalline state and examine its mechanical behavior using class B semicrystalline polymers such as PLA and PET whose Tg is above room temperature.

[1] Wang, S.-Q.; Cheng, S.; Lin, P.; Li, X. A phenomenological molecular model for yielding and brittle-ductile transition of polymer glasses. The Journal of chemical physics 2014, 141, (9), 094905