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Grafting of unsaturated acids and silanes to ethylene polymers: A kinetic model
Author(s) -
Motha Kshama,
Seppälä Jukka,
Bergström Christer
Publication year - 1989
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760292206
Subject(s) - materials science , ethylene , grafting , low density polyethylene , polyethylene , silanes , polymer chemistry , polymer , methyl acrylate , monomer , vinyl acetate , plug flow reactor model , butyl acrylate , residence time distribution , chemical engineering , continuous stirred tank reactor , thermodynamics , acrylate , organic chemistry , chemistry , copolymer , composite material , silane , catalysis , inclusion (mineral) , physics , engineering
A general kinetic model was developed to simulate the grafting of monomers such as unsaturated carboxylic acids and silanes to ethylene polymers. The polymers considered were ethylene‐co‐vinyl acetate (EVA), ethylene‐co‐butyl acrylate (EBA), and low‐density polyethylene (LDPE). Grafting was assumed to proceed by a free‐radical mechanism involving chain transfer. Organic peroxides having a strong tendency for hydrogen abstraction were selected as the source of primary radicals. The model simulated the grafting reaction as taking place in a single screw extruder. The residence time distribution in the extruder was experimentally determined by tracer analysis, according to which the extruder was a plug‐flow reactor connected to two mixed reactors in parallel. The model is able to predict the extent of grafting in terms of predefined parameters. Comparison of model predictions with available experimental data showed slight deviations, the possible causes of which are discussed. However, the kinetic behavior expected on the basis of the input parameters was observed, and, as such, the model allowed study of the effect of process variables on grafting kinetics and provided insight into the reaction mechanism.