Large size, sensitive response thermally expandable microspheres for the manufacture of suede-like leather

A large size, sensitive response thermally expandable microspheres (TEMs) for suede-like leather manufacture was prepared by suspension polymerization using acrylonitrile (AN), methyl methacrylate (MMA) and vinyl acetate (VAC) as the shell monomers and iso-pentane as the foaming component. The effect of the interfacial tension and viscosity of polymerization system on the particle size of TEMs, and in turn, the effect of the particle size of TEMs on the expansion temperature, expansion ratio and thermal response performance were investigated in detail. The results showed that increasing the interface tension and viscosity of the polymerization system was beneficial for preparing large size TEMs. Under the optimized conditions of 300 rpm, 25 wt% iso-pentane dosage, and 9:3:1 mass ratio of AN/MAA/VAC, the TEMs shown above 100 mu m particle size and 4 times expansion ratio at 150?. Moreover, TEMs with 18% encapsulation ratio (E-r) of the foaming component can complete foaming in the narrow temperature range (delta T <= 10?), showing a sensitive thermal response. The mixture of waterborne polyurethane and quantitative TEMs was coated on the surface of synthetic leather base, and a new type of suede-like leather was obtained after foaming, which can substitute genuine suede leather.

Automated summary

This study investigated the effect of interfacial tension and viscosity of the polymerization system on the particle size of thermally expandable microspheres (TEMs), and the impact of TEMs particle size on expansion temperature, expansion ratio, and thermal response performance. The results showed that under optimized conditions, TEMs exhibited large particle size and high expansion ratio at 150? and demonstrated sensitive thermal response. Coating a mixture of waterborne polyurethane and TEMs on a synthetic leather base resulted in a new type of suede-like leather that can replace genuine suede leather.