It is an addition polymer synthesized by free-radial- activatedpolymerization of ethylene, where the molecular weight may be as low as from 2000 to 4000;
这是一种加聚物，由乙烯经自由基活化聚合而成，其相对分子质量可低至2000～4000。
2
On the basis of former studies, a mechanism of group transfer polymerizationactivated by ionic field was proposed.
在已有基团转移聚合机理研究的基础上，提出特种离子场活化聚合机理。
3
The surface of polypropylene microporous membranes was activated by the graft polymerization of methyl methacrylate initiated with ultraviolet-photo.