posted on 2021-10-06, 01:44authored byJincheng Dai, Chenjie Yu, Shuyao Ye, Wei Li, Xue Kang, Yao Yang, Peng Liang, Yulong Ma, Zhengliang Huang, Binbo Jiang, Jingdai Wang, Yongrong Yang
The
inert nitrogen microbubbles are incorporated during ethylene
slurry polymerization to retard the formation of chain entanglements
through the intermittent dormancy of living polymer chains. This dormancy
effect is endowed by the highly frequent and intensive collisions
of countless microbubbles on the growing polyethylene particles, which
blocks the transfer channel of reactants on the particle surface. It is evidenced that the transfer
barrier slows down the chain propagation and provides extra time for
the propagated chains to be crystallized. Thus, the nascent polyethylene
with the reduced entanglements and a considerable amount of monoclinic
lamellae is achieved by the catalyst with the original ability to
synthesize the highly entangled polyethylene. The synchronous increment
of stiffness, toughness, and strength is found for the synthesized
polyethylene owing to the reduced chain entanglements.