Abstract

The correlations between the comonomer ratio of vinyl polymer tanning agents and their application properties were studied by the two-power regression orthogonal design. Eight monomers (AN-acrylonitrile, AM-acrylamide, MAA-methyl acrylic acid, MMA-methyl methacrylate, VAc-vinyl acetate, MA-methyl acrylate, EA-ethyl acrylate, BA-butyl acrylate) were separately chosen to copolymerize with acrylic acid (AA) to form the corresponding copolymers.We measured ten proper indexes of the application properties for each copolymer used in retanning such as thickness increment ratio, shrinking temperature increment, phy-mech properties, compressibility factor etc. The effects of the eight comonomers (AN, AM, MAA, MMA, VAc, MA, EA, BA) on the property indexes of the leather samples were also discussed.

It has been found that the comonomers with polar groups can increase the tensile strength and the shrinking temperature of the leather samples, but they may affect the softness of the leather samples and the pliability of the collagen fibrils.

The comonomer of AM makes an outstanding contribution to the fullness of leather samples. The acrylate comonomers, such as MA, EA, BA, can improve the pliability of collagen fibrils of retanned leather samples and the improvement extent is related to the carbon chain length of the ester groups. The comonomers with methyl groups (such as MAA, MMA) can decrease the pliability of the leather samples.