改性四氟乙烯-丙烯共聚橡胶的合成和性能

Synthesis and Properties of Modified Tetrafluoroethylene-Propylene Copolymer Rubbers

采用由过硫酸铵-甲醛次硫酸钠-硫酸亚铁-乙二胺四乙酸二钠组成的氧化-还原引发体系,经乳液聚合制备了少量巴豆酸乙烯酯(VCA)或甲基丙烯酸乙烯酯(VMA)改性的四氟乙烯-丙烯(TFE-P)共聚物生胶,对硫化前后的共聚物结构、硫化胶的拉伸性能和热稳定性等进行研究。发现VCA或VMA可有效共聚进入共聚物分子链,并导致共聚物平均相对分子质量的降低;少量VCA或VMA的引入显著提高了TFE-P共聚物的可交联性,并提高了硫化胶的拉伸强度和热稳定性,未补强TPE-P-VCA共聚物硫化胶的拉伸强度达16 MPa,断裂伸长率可达360%,补强后TPE-P-VCA共聚物硫化胶拉伸强度达19.8 MPa,断裂伸长率可达190%。

Tetrafluoroethylene-propylene（TFE-P）copolymers containing low content of vinyl crotonate（VCA）or vinyl methacrylate（VMA）were prepared by emulsion polymerizations at low temperature,using a redox initiator system containing ammonium peroxodisulfate,hydroxymethane sulfinate,ferrous sulfate and ethylenediamine tetraacetic.The structure of uncrosslinked and crosslinked copolymers,and tensile and thermal properties of crosslinked copolymers were investigated.It is shown that VCA and VMA could be effectively incorporated into the copolymer chains,and the molecular weight of copolymers is decreased as VCA or VMA is incorporated.The crosslinking degree of modified TFE-P copolymers is greater than that of TFE-P copolymer under the same crosslinking conditions.The TFE-P-VCA copolymers exhibit better tensile properties and thermal stability than TFE-P copolymer.The tensile strength of crosslinked TFE-P-VCA copolymer without reinforcing filler is increased to be 16 MPa,and elongation at break reaches 360%,and the tensile strength of crosslinked and reinforced TFE-P-VCA copolymer is improved to be 19.8MPa,and the elongation at break is about 190%.