Journal ArticleDOI
The crystallinity of poly(phenylene sulfide) and its effect on polymer properties
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TLDR
In this paper, an approximate degree of crystallinity, termed crystallinity index (Ci), could be readily assigned based on x-ray measurements, based on which a poly(phenylene sulfide) molding with very low surface crystallinity was obtained.Abstract:
The crystallinity and crystallizability of poly(phenylene sulfide) have been examined by a number of common techniques. Several provided qualitative information, but only one, x-ray diffraction, was considered sufficiently reliable and reproducible to allow quantitative comparisons. Based on x-ray measurements, an approximate degree of crystallinity, termed crystallinity index (Ci), could be readily assigned. According to this method, virgin polymer possesses significant crystallinity (Ci ≈ 65%). Curing (crosslinking) the resin below its melting point did not change the crystallinity but did affect the crystallizability. Lightly cured resin suitable for molding and film extrusion was easily quenched from the melt to give amorphous polymer. The amorphous samples crystallized rapidly when heated to temperatures > 121°C (250°F). At mold temperatures below 93°C (200°F), moldings with very low surface crystallinity were produced. Annealing (204°C, 400°F) caused rapid crystallization of such moldings, and changes in crystallinity were correlated with observed changes in physical properties. The resin crystallizes so rapidly that these quenched moldings possessed a crystallinity gradient, the internal crystallinity being substantially greater. At high mold temperatures (121–204°C, 250–400°F), moldings very similar to fully annealed specimens were obtained.read more
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Crystallization, morphology, and thermal behavior of poly(p‐phenylene sulfide)
TL;DR: In this paper, the structure, crystallization, morphology, and thermal behavior of poly(p-phenylene sulfide) with low-molecular mass, probed by DSC, optical, and electron microscopy, were investigated.
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Thermal behaviour of poly(phenylene sulfide) and its derivatives
TL;DR: In this article, the thermal properties of poly(phenylene sulfide) (PPS) and its derivatives were investigated by differential scanning calorimetry and thermogravimetric analysis.
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Irradiation effects on aromatic polymers: 3. Changes in thermal properties by gamma irradiation
TL;DR: In this paper, the effects of gamma irradiation under vacuum on the thermal properties and crystallization behaviour of poly (ether ether ketone) (PEEK-a, amorphous; PEEK-c, crystalline) have been investigated.
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Thermal and rheological properties of poly(phenylene sulfide) and poly(ether etherketone) resins and composites
TL;DR: In this article, the effects of processing cycles and environment on the thermal and rheological properties of PPS and PEEk materials are discussed, and the effect of carbon fiber reinforced prepregs on thermal stability is investigated.
Journal ArticleDOI
On the weld strength of in situ tape placed reinforcements on weave reinforced structures
TL;DR: In this paper, unidirectionally reinforced thermoplastic tapes were welded onto woven fabric reinforced laminates using a laser assisted tape placement process, and a mandrel peel setup was used to quantify the interfacial fracture toughness between the tape and the laminate.