摘要
聚合物利用低温等离子体预辐照进行表面接枝共聚合已有报道.此方法的优点是接枝层被限制在聚合物表面,辐照过程对基材本体性质无影响,且整个过程对环境无污染. 用等离子体使聚合物表面产生自由基,不需要表面具有不饱和键或特殊官能团,因而适用于任何聚合物,甚至于一些无机物如玻璃等.利用等离子辐照后暴露于空气的聚合物表面上生成的过氧自由基或过氧化物进行接枝反应,一般接枝量不大.本工作中,我们自己设计了反应器,以超高分子量聚乙烯(UHMWPE)为基材,以甲基丙烯酸甲酯(MMA)为接枝单体,在无氧条件下利用等离子体辐照产生的表面自由基进行了接枝聚合,产物接枝量高达10％.还用顺磁共振技术对表面自由基性质及其在接枝过程中的行为进行了跟踪研究.
A large number of free radicals are produced on the surface of PE to be irradiated by plasma, the ESR measurement for this kind of radicals in vacuum showed a five -line spectrum, which can be assigned to the free radical -CH2CH2 · . The radical translate to a peroxide free radical as it contacts with air, and to a PMMA free radical as it contacts with monomer MMA. The results show that the free radical on the surface of PE to be irradiated by plasma can initiate the graft copolymerization of monomer MMA. The graft amount measured by IR spectra increases with postpolymerization time, and reaches as highly as 10% (weight ratio). The stability of the PMMA free radicals, and the dependence of the graft amount on postpolymerization time indicate the graft chain has activity and the free radical in the chain end does not terminate.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
1992年第2期278-280,共3页
Chemical Journal of Chinese Universities
基金
国家自然科学基金
关键词
等离子体
接枝共聚合
辐照
聚乙烯
Plasma, Surface, Surface free radical, Graft copolymerization
