In‐situ compatibilization of thermoplastic polyurethane and polydimethyl siloxane rubber by using ethylene methyl acrylate copolymer as a reactive polymeric compatibilizer

The effect of Ethylene Methyl Acrylate (EMA) copolymer as a reactive polymeric compatibilizer in a blend of 50:50 Thermoplastic Polyurethane (TPU)-Polydimethylsiloxane (PDMS) rubber has been studied. The compatibility was proved by mechanical property measurements and phase morphology studies. EMA reacted with PDMS rubber at 180°C at 100 rpm rotor speed during melt mixing to produce EMA-g-PDMS rubber in situ, which acted as the compatibilizer for the binary system of TPU and PDMS rubber. EMA-g-PDMS rubber is believed to undergo specific interaction via hydrogen bonding with the TPU matrix through the CO group of EMA and the unassociated NH group of TPU, whereas the PDMS rubber in the EMA-g-PDMS disperses well with the bulk PDMS matrix. The phase morphology studies showed a drastic reduction in the size of the dispersed phase at the optimum concentration of EMA. © 1995 John Wiley & Sons, Inc.