Synchronously strengthening and plasticizing of unsaturated polyester resin based on styrene-maleic anhydride oligomer

To synchronously strength and plasticize unsaturated polyester resin (UPR), maleic anhydride were directly added in the unsaturated polyester resin solution and form the styrene-maleic anhydride oligomer (SMAO) without initiation. The creating SMAO cross link with UPR by curing reaction, and the prepared UPR resin exhibit higher tensile, elongation, bending strength and higher impact strength simultaneously, 0.45, 0.36, 0.76 and 0.12 times than UPR matrix, SMAO-UPR exhibits obvious plastic fracture characteristics; The DSC result indicates that the curing degree of SMAO-UPR is 96.55% which is 1.45% lower than that of UPR; The TG result indicates that MA and St mainly form an alternating copolymer below 90°C. The SEM and DMA result indicates that SMAO improves the morphology and structure which shows plastic deformation of UPR, and there is a certain interface effect between SMAO and UPR. Compared with the traditional method of large molecular weight SMA modified UPR, this method of reinforcing UPR is better for mechanical property, easy to operate, inexpensive, and highly applicable in industrial production.