临界链长 meaning in English
critical chain length
Examples
- The urea - formaldehyde ( uf ) polymer / sio2 composite microspheres were prepared by polymerization - induced colloid aggregation ( pica ) method . the formation mechanism of composite microspheres is attributed to the fact that that urea and formaldehyde firstly undergo acid - catalyzed polymerization to form oligomers , and then the sol particles are adsorbed on the chain of oligomers by wan der walls force and hydrogen bonding . when the oligomers reach the critical chain length , they separate from solution due to phase separation
对复合微球形成机理的研究表明，尿素和甲醛在酸性条件下自身聚合可以形成高分子微球，在sio _ 2酸性溶胶中发生聚和反应时，随着反应的进行，齐聚物不断生成， sio _ 2胶体颗粒逐渐吸附在齐聚物分子链上，当聚合物链达到沉淀临界链长时，由于相分离作用，从前驱物溶液中析出，同时sio _ 2胶体颗粒均匀的分布在脲醛聚合物网络中，随之沉淀出来，形成脲醛sio _ 2复合微球。