Synthesis of Vinyl Chloride-Vinyl Terminated Polydimethylsiloxane Cross-Linked Microspheres and Their Influence on the Mechanical and Surface Properties of Rigid Polyvinyl Chloride Composites

Abstract

Introducing siloxane components into polymer molecular chains can impart materials with unique properties such as low surface energy, antifouling, and wear resistance. In this work, we synthesized cross-linked polymeric microspheres via a self-stabilized precipitation polymerization (2SP) strategy involving vinyl chloride (VC), vinyl polydimethylsiloxane (VPDMS), and diallyl maleate (DAM), followed by an investigation of their (CL-P[(VC)-co-(VPDMS)]) effects within the PVC matrix. Fourier infrared spectroscopy (FTIR), solid-state 13C nuclear magnetic resonance (SS 13C NMR), proton nuclear magnetic resonance (1H NMR), and X-ray photoelectron spectroscopy (XPS) confirmed the successful synthesis of cross-linked copolymers. By adjusting the feed ratio of DAM, the copolymer microspheres with controllable gel content (GC, 20–95%), tunable number-average diameter (Dn, 400–1400 nm), and uniform particle size distribution (PSD, ∼1.02) could be obtained. By employing CL-P[(VC)-co-(PDMS)] as a polymeric filler in a rigid PVC system, it exhibited polymeric lubricant features during the processing, where the plasticizing time increased and the melt temperature has a slight decrease with the filler content. Simultaneously, CL-P[(VC)-co-(VPDMS)] also demonstrates good wear resistance. For instance, by adding 3 phr CL5-P[(VC)80-co-(VPDMS)20] in PVC matrix, the specific wear rate of the composite was reduced to 5.1 × 10–5 mm3/Nm, about one-quarter of that of rigid PVC. Uniaxial tensile tests and impact tests showed that the addition of cross-linked microspheres had little effect on the mechanical properties of PVC.