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Migration of Additives in Polymer Coatings: Phosphonated Additives and Poly(vinylidene chloride)‐Based Matrix
Author(s) -
Rixens Bérengère,
Severac Romain,
Boutevin Bernard,
LacroixDesmazes Patrick,
Hervaud Yves
Publication year - 2005
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.200500030
Subject(s) - copolymer , polymer chemistry , polymer , coating , scanning electron microscope , materials science , hydrolysis , metal , chloride , chemistry , chemical engineering , composite material , organic chemistry , metallurgy , engineering
Summary: The living radical terpolymerization of vinylidene chloride (VC 2 ), methyl acrylate (MA), and dimethyl‐2‐methacryloxyethylphosphonate (MAPHOS) was performed at 70 °C in benzene by a reversible addition fragmentation chain transfer (RAFT) process to yield a gradient terpolymer of controlled molecular weight ( $\overline M _{\rm n}$ = 5 800 g · mol −1 , I p = 1.53) with a molar composition of 75:14:11 (VC 2 /MA/MAPHOS). Such terpolymers, hydrolyzed (phosphonic acid groups) or not, were used as polymeric additives in coating formulations based on a poly(VC 2 ‐ co ‐MA) copolymer matrix ( $\overline M _{\rm n}$ = 63 300 g · mol −1 , I p = 1.99, VC 2 /MA = 80:20 molar ratio). The formulations were spun cast on stainless steel surfaces and the coatings were observed by scanning electron microscopy (SEM) coupled with X‐ray analyses (EDX). The hydrolyzed additive was shown to both segregate and migrate towards the metal interface, leading to a preferential organization of the coating. Hence, the matrix at the air surface acts as a barrier to gas while the additive ensures adhesion at the polymer/metal interface.SEM photograph of a section of the coating with formulation 4 [poly(VC 2 ‐ co ‐MA‐ co ‐MAPHOS(OH) 2 ) (75:14:11)].