基于星型单体与RAFT相结合的超支化聚合物的合成与评价

SYNTHESIS AND EVALUATION OF HYPERBRANCHED POLYMERS BASED ON STAR MONOMERS AND RAFT POLYMERIZATION

为改变线性聚合物分子链长,高温下易剪切断链,抗温抗盐能力不足等缺点,在单体及组成一定的情况,通过改变聚合物的分子构象,采用可逆加成-断裂链转移聚合(RAFT)法,基于星型单体与RAFT相结合制备得到黏度效应低、抗温抗盐能力强的超支化聚合物EHBPS-P。性能评价结果表明,EHBPS-P抗温可达220℃,加入超支化聚合物的基浆在220℃老化后黏度降低率为66.7%(同组分线性聚合物黏度降低率达90.98%),淡水、盐水、复合盐水基浆中加量为1.0%(质量分数)时,可使钻井液的滤失量控制在10.0 mL以内,优于线性聚合物,有较好持续抗温性和长效的作用周期。

Linear polymers have long molecular chains and are prone to chain breakage at high temperatures,resulting in insufficient temperature and salt resistance.In the case of certain monomer and composition,by changing the molecular conformation of the polymer,the reversible addition fragmentation chain transfer polymerization(RAFT)method was used to prepare hyperhyperized polymer EHBPS-P with low viscosity and strong temperature and salt resistance,based on the combination of star monomer and RAFT.The performance evaluation results show that the temperature resistance of EHBPS-P can reach 220℃,and the viscosity reduction rate of the base slurry with hyperextended polymer is 66.7%after aging at 220℃.The viscosity reduction rate of the base slurry with liner polymers with same components is 90.98%after aging at 220℃.When the dosage of fresh water,salt water and compound salt water base slurry is 1.0%,the filtration loss of drilling fluid can be controlled within 10.0 mL,which is better than that of linear polymer.It shows good continuous temperature resistance and long action cycle.