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Grafting of polystyrene branches to polyethylene and polypropylene
Author(s) -
Park EunSoo,
Jin HyoungJoon,
Lee IkMo,
Kim MalNam,
Lee Han Sup,
Yoon JinSan
Publication year - 2001
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.10110
Subject(s) - polystyrene , copolymer , polymer chemistry , polypropylene , polyethylene , materials science , polymerization , grafting , styrene , benzoyl peroxide , polymer , composite material
Abstract Polyethylene (PE) and polypropylene (PP) were reacted with benzoyl peroxide (BPO) and 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO) to prepare PE‐TEMPO and PP‐TEMPO macroinitiators, respectively. Molecular weight of PP decreased, whereas that of PE increased during the reaction with the BPO/TEMPO system. Polystyrene (PS) branches were grafted to PE and PP backbone chains as a result of bulk polymerization of styrene with the PE‐TEMPO and PP‐TEMPO macroinitiators. A significant amount of PS homopolymer was produced as a byproduct. Weight of the resulting PE‐ g ‐PS and PP‐ g ‐PS increased with the polymerization time up to 20 h and then leveled off. Melting point of PE and PP domains in PE‐ g ‐PS and PP‐ g ‐PS, respectively, lowered as the content of PS in the copolymers increased. However, glass transition of the copolymers was almost identical with that of PS homopolymer, indicating that the constituents in the copolymers were all phase‐separated from each other. In scanning electron microscopy of the incompatible PE/PS, PP/PS, and PE/PP/PS compounded with PE‐ g ‐PS and PP‐ g ‐PS, any clear indication of enhanced adhesion between the phases was not observed. However, phase domains in the blends were, nevertheless, reduced significantly to raise mechanical properties such as maximum stress and elongation at break by 20–75%. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1103–1111, 2002