Morphology and mechanical properties of urethane link polydimethylsiloxane-perlite microsphere composites

초록

Hollow spheres are used as lightweight filler in composite to fill polymer resin for specific characteristics such as low density, dimension stability, impact strength, thermal insulation, and cost saving. In this study we have investigated the silane treatment effects of perlite expanded hollow sphere (PEHS) on the properties of urethane link polydimethylsiloxane (UPDMS) composites prepared by in-situ polymerization method. The aim was to enhance interactions at the matrix/filler interface and to improve the distribution of the filler in the UPDMS matrix. A series of UPDMS/PEHS composites were prepared by in-situ polymerization which were based on polyoxytetramethylene glycol (PTMG), 1,4-phenylene diisocyanate (PDI), and diisocyanate terminated PDMS (IT-PDMS). The PTMG was first melted by heating at 100 °C for 1 h. The required amount of PEHS was dispersed in the PTMG at 50 °C by mechanical premixing and bath sonication for 2 h. Composites of 1–10 wt% PEHS were obtained, depending on the PEHS and monomer ratio. The yield of the UPDMS (> 98 %) was unaffected by the addition of PEHS. The synthesized composites were fully characterized by FTIR, SEM, TGA, and by measurements of mechanical properties and hydrolysis resistance. Increased tensile strength and elongation at break were obtained for UPDMS/PEHS composites with silane-treated PEHS. This can be explained as the consequence of better stress transfer through the composite due to an improved adhesion between matrix polymer and silane-treated filler.