We report a systematic study of melt memory in semicrystalline polar polymers using model series of poly(ε-caprolactone) and poly(ethylene oxide). By combining polymer synthesis, DSC self-nucleation, SAXS, and rheology over a broad molecular-weight range, we disentangle the respective roles of chain length, intermolecular interactions, and entanglements. Our results demonstrate that melt memory can emerge below the entanglement molecular weight when intermolecular interactions are sufficiently strong, while entanglements further amplify the effect. The study establishes a unified framework linking molecular architecture to melt memory in polar polymers.

We demonstrate that aqueous phase-transfer catalysis enables selective iodination of PVC under mild and sustainable conditions. Subsequent reaction with a DBU-based CO₂-binding amine (CO₂BAM) achieves efficient S_N2 substitution at CH-X centers, improving CO₂ incorporation fourfold relative to previous CO₂BAL strategies, reaching a 10 mol% yiled. The polymer remains fully soluble, demonstrating a greener, safer, and effective approach to PVC structural modification.

https://doi.org/10.1039/D6RA00749J

This work investigates how chain stereoconfiguration and molecular weight affect the crystallization of poly(propylene oxide) (PPO). Although enantiopure PPO-R and PPO-S crystallize into the same crystal structure, clear and reproducible differences in crystallization kinetics are observed, with an unexpected inversion as molecular weight increases. Racemic PPO-R:S blends show slower crystallization without stereocomplex formation, highlighting subtle chirality-driven effects in the melt and offering new strategies to tune crystallization in PPO-based materials.

Here, we report a three-step strategy enabling efficient cyclization of high-M_n PLLA at 0.5 M. Key to success is a persistent tripartite complex driven by hydrogen bonding and ion pairing. Selective intramolecular transesterification at a benzylic ester triggers ring closure, affording cyclic PLLA (M_n ≈ 26,000 g/mol) under synthetically practical conditions. SPM imaging reveals nanorings with diameters consistent with the expected contour length of cyclic PLLA chains.

Here we show that highly transesterified poly(L-lactide-co-caprolactone) (P(LLA-co-CL)) copolymers undergo low-temperature depolymerization with exceptional selectivity for L-lactide (LLA). Upon vacuum distillation at 230 °C, distillates are recovered that are highly enriched in LLA (up to 96-99 mol%), while the polymer residues reorganize into higher-molar-mass polycaprolactone (PCL) chains sporadically decorated with lactoyl units. The recycling process combines the selective regeneration of virgin-quality LLA with the generation of unprecedented “upcycled PCL” architectures, distinct from conventional PCL and offering new opportunities for property design.