Polymerization from the vapor phase. I. Poly(p‐phenyleneterephthalamide) gas barrier coatings

Abstract

SynopsisAn atmospheric-pressure, vapor-phase polymerization technique was used to deposit thin (1-10 pm) poly(p-phenyleneterephthalamide) coatings onto polyester film and other sheet substrates. A minimum deposition temperature of 17OOC was found to be critical. When substrate temperatures were below 17OoC, coatings were loosely adhered, powdery, and of low molecular weight; above 17OoC, coherent, well-adhered, high molecular weight coatings were obtained. These vapor-deposited coatings exhibited exceptionally good oxygen barrier properties and were found to consist of fused 0.1-pm particulates. Scanning electron microscopy (SEM) of the top surfaces of these coatings clearly revealed their particulate origin. Similar evidence was also obtiined from SEM examination of fracture surfaces and transmission electron microscopy of microtomed sections. The coalescence of these coatings was demonstrated by SEM of plasma-etched surfaces and oxygen permeability information. The uniplanar orientation of the polymer crystals in these multiparticulate coatings was strong evidence for the epitaxial growth of the crystals.

Polyamides, Aromatic

“…Vapor Phase Polymerization PPTA can be formed by vapor phase polymerization at temperatures above 2508C (31). The polymer produced appears to have a high degree of branching, which makes the spinning of fibers with high strength more difficult.…”

Interest and durability of multilayers: from model films to complex films

“…It generally increases with increasing permeant concentration, temperature, pressure difference, and decreases with increasing crystallinity, permeant size, chain stiffness, cohesive energy density, etc 17–20. High barrier polymers have been developed, for example, the poly(vinylidiene)chloride (PVDC),21 poly(ethylene vinyl) alcohols (EVOH),22 polyamides,23 sulfonated HDPE,24 poly( p ‐phenyleneterephthalamise) (PPTA),25 and liquid crystalline polymers (LCPs)26–28 which suffer from their high price 29. Developments of gas barrier thin film on polymer substrates started in 1959 with aluminum metallization technique 30.…”

High electro-optic side-chain polymer by vapor deposition polymerization

“…In 1980, Ikeda et al 5 first reported the technique of in situ vapor deposition of monomers and polymerization ͑via step growth, not plasma͒ in vapor phase or vapor deposition polymerization ͑VDP͒. They reported the formation of Kevlar or poly͑p-phenyleneterephthalamide͒ via the simultaneous vapor deposition of p-phenylene diamine and terephthaloyl chloride, and since then, several others have performed VDPs using many different monomer combinations.…”