Super-tough PVC/CPE composites: an efficient CPE network by an MGA copolymer prepared through a vibro-milling process
Abstract
Vibro-milling, a solid-phase mechanochemistry method, was used to prepare an amphiphilic composite particle, which is referred to as MGA. The Molau test, Fourier-transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) results indicated that the core–shell structure of the acrylic impact modifier, acrylate core–shell rubber (ACR), was destroyed after vibro-milling. The ACR core was exposed and reacted with polyvinyl chloride (PVC) chains. Using 1.75 parts per hundred rubber (phr) MGA instead of 1.25 phr MC and 0.5 phr ACR, a significant enhancement effect was achieved. The notched impact strength of the PVC composites increased from 4.24 kJ m−2 for neat PVC and 23.79 kJ m−2 for C7A0.5MC1.25 to 65.5 kJ m−2 for C7M1.75. Additionally, the tensile strength and elongation at break of the PVC composites were enhanced. Studies using a variety of characterization techniques show that the addition of MGA can promote the formation of an intermingled and riveted structure, and thus increase interfacial interactions and the effects of stress transfer, releasing the planar strain. The introduction of MGA can also induce the chlorinated polyethylene (CPE) phase to form a network structure at a lower CPE content, which contributes to networking and crazing and is the main toughening mechanism.