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Microstructural Evolution in Linear Low Density Polyethylene During Peroxide Modification: A Monte Carlo Simulation Study
Author(s) -
Golriz Mahdi,
Khonakdar Hossein Ali,
Morshedian Jalil,
Jafari Seyed Hassan,
Mohammadi Yousef,
Wagenknecht Udo
Publication year - 2013
Publication title -
macromolecular theory and simulations
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.37
H-Index - 56
eISSN - 1521-3919
pISSN - 1022-1344
DOI - 10.1002/mats.201300118
Subject(s) - linear low density polyethylene , branching (polymer chemistry) , peroxide , monte carlo method , polyethylene , polymer chemistry , molecule , organic peroxide , materials science , linear relationship , chemistry , chemical engineering , composite material , organic chemistry , polymer , copolymer , statistics , mathematics , engineering
A Monte Carlo (MC) simulation is performed on peroxide induced branching reactions in a linear low density polyethylene (LLDPE) melt processed with different dicumyl peroxide (DCP) concentrations at various processing times and temperatures. The MC simulation can successfully monitor the microstructural changes due to the induced long chain branching (LCB), decreased terminal double bonds, and increased trans vinyl bonds in LLDPE during peroxide modification. The induced structural changes are in good agreement with the experimental results obtained by rheometery and SEC analysis. The changes in the gel content,M ‾ w , and MWD as a result of the peroxide modification are also determined. The simulation results also reveal that the chemical mechanism by which the modification proceeded is closely related to the changes in concentrations of reactive vinyl species of the PE molecules. Moreover, the results indicate that the degree of induced LCB increases almost linearly with the DCP concentrations. The findings of this paper indicate that the MC simulation method is able to predict the suitable processing conditions needed for inducing desirable structural changes in a LLDPE.