Barbier polymerization towards synthesizing polar polyolefin analogues for polyolefin modification

Abstract

The non-polar characteristics of polyolefins limit their applications. Introducing polar functional groups to polyolefins can greatly improve their properties and further expand their application range. Here, a Barbier polymerization method is demonstrated to be a versatile strategy to synthesize polar polyolefin analogues (PPAs), which are further utilized as modifiers to improve the properties of non-polar polyolefins by physically introducing polar functional groups. Through this Barbier polymerization method, a series of novel hydroxyl group-containing PPAs are synthesized. The successful preparations of PPAs are characterized by nuclear magnetic resonance, gel permeation chromatography and Fourier transform infrared spectroscopy. PPAs are further applied as modifiers of linear low-density polyethylene (LLDPE). Characterization studies including scanning electron microscopy, differential scanning calorimetry, contact angle measurements, rheological testing, and tensile testing reveal that the addition of PPA successfully improves the processability, hydrophilicity, tensile performance, crystallization and elasticity of LLDPE. This work therefore not only expands the structural and functional libraries of monomers and polymers but also presents a novel method for the physical modification of LLDPE and thus might inspire advancements in the fields of polymerization, processing and modification of polyolefins.