TY - JOUR
T1 - Roles of cyclic units in copolyethylene crystallization
T2 - A molecular dynamics simulation
AU - Yang, Yong Biao
AU - Li, Ze Sheng
AU - Yang, Hua
AU - Lu, Zhong Yuan
AU - Sun, Chia Chung
PY - 2004/12
Y1 - 2004/12
N2 - Molecular dynamics (MD) simulations of several polyethylene copolymer chains containing 1,2-, 1,3- or 1,4-disubstituted cyclopentane or hexamethylene structures in the main chain (with 500 CH2) are performed to investigate the influence of cyclic units on the crystallization properties of polyethylene (PE). From the isothermal relaxation process it is found that they generally collapse to a globule via a local collapse process. The copolymer chains containing 1,2-disubstituted cycloparaffin structures form more kinks and take shorter time to totally collapse into a single globule than the others. Moreover, from the morphology of the crystal structures after annealing it is found that the copolymer chains containing 1,2-disubstituted cycloparaffin structures can yield more ordered structures with cyclic units rejected to the fold surface. For the copolymer chains containing 1,3- or 1,4-disubstituted cycloparaffin, the lamellar structures are not perfect and some cyclic units are always incorporated in the crystalline phase.
AB - Molecular dynamics (MD) simulations of several polyethylene copolymer chains containing 1,2-, 1,3- or 1,4-disubstituted cyclopentane or hexamethylene structures in the main chain (with 500 CH2) are performed to investigate the influence of cyclic units on the crystallization properties of polyethylene (PE). From the isothermal relaxation process it is found that they generally collapse to a globule via a local collapse process. The copolymer chains containing 1,2-disubstituted cycloparaffin structures form more kinks and take shorter time to totally collapse into a single globule than the others. Moreover, from the morphology of the crystal structures after annealing it is found that the copolymer chains containing 1,2-disubstituted cycloparaffin structures can yield more ordered structures with cyclic units rejected to the fold surface. For the copolymer chains containing 1,3- or 1,4-disubstituted cycloparaffin, the lamellar structures are not perfect and some cyclic units are always incorporated in the crystalline phase.
KW - Crystallization
KW - Molecular dynamics simulation
KW - Polyethylene
UR - http://www.scopus.com/inward/record.url?scp=9344244756&partnerID=8YFLogxK
U2 - 10.1016/j.polymer.2004.10.043
DO - 10.1016/j.polymer.2004.10.043
M3 - Article
AN - SCOPUS:9344244756
SN - 0032-3861
VL - 45
SP - 9047
EP - 9055
JO - Polymer
JF - Polymer
IS - 26
ER -