Solvent‐induced crystallinity in poly(aryl‐ether‐ether‐ketone) [PEEK]

Abstract

The amount and structure of the crystals formed by the solvent‐induced crystallization (SIC) following a sorption‐desorption cycle of five fluids (benzene, toluene, chloroform, methylene chloride, and carbon disulfide) in amorphous PEEK was determined by wideangle x‐ray scattering (WAXS). The SIC crystal structure was compared with that produced by thermal methods, both those formed at low temperature by heating the amorphous material 10–20°C above Tg or by cooling from the melt. Although smaller in size, the SIC crystals are tighter and more organized than those produced thermally. The WAXS data indicates that all five fluids produce approximately 35% crystallinity in PEEK. Gravimetric data suggest that a low‐density region, consisting of either microvoids or highly disordered amorphous region, surrounds the crystals.

Poly(ether ether ketone) (PEEK)-based graft-type polymer electrolyte membranes having high crystallinity for high conducting and mechanical properties under various humidified conditions

“…Because it has been reported that solvent-induced recrystallization of the amorphous PEEK solid proceeded at approximately 50 C because of the lowering of the glass transition temperature (T g ), the amorphous phase in the PEEK substrate recrystallized during thermal gra polymerization of DVB. [54][55][56] The DOCs of the graed-PEEK and PEEK-PEM (22% and 18%) were lower than that of PEEK-DVB because of the introduction of amorphous poly(ETSS) and PSSA gras. However, considering only a PEEK substrate area (in particular, subtracting the gra-polymer phases from the PEMs), the DOC 0 s of these lms (namely, subtracting the gra-polymer phases from the PEMs) were 36% and 31%.…”

Compressed‐gas‐induced crystallization in tert‐butyl poly(ether ether ketone)

“…The T g depression and crystallization induced by the dissolved, low molecular weight species are related to their solubility in and interactions with the polymers. Although liquid‐ and vapor‐induced crystallizations of polymers such as poly(ether ether ketone) (PEEK),1, 2 polycarbonate (PC),3, 4 and poly(ethylene terephthalate) (PET)5, 6 have been extensively studied, there have been only limited investigations on compressed‐gas‐induced crystallization. CO 2 ‐induced crystallization in poly(vinylidene fluoride),7 PET,8, 9 PC,10 poly(phenylene sulfide) (PPS),11 PEEK,12 methyl‐substituted poly(ether ether ketone) (MePEEK),13 and syndiotactic polystyrene (sPS)14 has been reported recently.…”