Mixtures of poly(ethylene terephthalate) and liquid‐crystalline polyesters with Y‐shaped mesogens

Abstract

Some liquid-crystalline polyesters (LCP) with Y-shaped mesogens, differing only in the length of their spacers, were blended with poly(ethy1ene terephthalate) (PET). Calorimetric measurements show significant influence of the LCP on the crystallization of PET even at low concentrations. The mixtures are spun into fibres and their mechanical properties are compared with fibres made from pure LCPs. The formation of LCP-fibrils leads to improved values of Young's modulus and tensile strength. ZUSAMMENFASSUNG:Einige flussigkristalline Polyester (LCP) mit Y-formigen Mesogenen, die sich voneinander nur durch die Lange ihrer Spacer unterscheiden, wurden mit Poly(eth1enterephthalat) (PET) gemischt. Kalorimetrische Untersuchungen zeigen einen deutlichen Ein-flu8 der LCPs auf die Kristallisation des PET schon bei niedrigen Konzentrationen. Die Mischungen werden zu Fasern gesponnen, deren mechanische Eigenschaften mit denen aus den reinen LCPs verglichen werden. Die Bildung von LCP-Fibrillen fuhrt zu einer Erhohung des Elastizitatsmoduls und der Zugfestigkeiten.

Ionization–liquid‐crystalline polymer synergistically reinforced poly(ethylene terephthalate) due to interfacial compatibilization by ion–dipole interactions

“…The thermal transition of HBA–HNA was not found in these composites, probably due to its transition peak being too weak to observe. Figure 6(a,a′) and Table 2 show that the melt crystallization temperature ( T mc ) and enthalpy (Δ H mc ) and melting temperature ( T m ) and enthalpy (Δ H m ) values of the PET matrices in the PET‐N/LCP (Traces 2–4) were clearly higher than those of the PET (Trace 1), indicating that HBA–HNA could act as a nucleating agent to promote PET crystallization 34,35 . The glass transition temperature ( T g ) values remained between 85.7 and 86.8 °C (Traces 1–4) presumably due to the small mass fractions of HBA–HNA not substantially affecting the T g values of the respective PET matrices.…”

“…Figure 6(a,a 0 ) and Table 2 show that the melt crystallization temperature (T mc ) and enthalpy (ΔH mc ) and melting temperature (T m ) and enthalpy (ΔH m ) values of the PET matrices in the PET-N/LCP (Traces 2-4) were clearly higher than those of the PET (Trace 1), indicating that HBA-HNA could act as a nucleating agent to promote PET crystallization. 34,35 The glass transition temperature (T g ) values remained between 85.7 and 86.8 C (Traces 1-4) presumably due to the small mass fractions of HBA-HNA not substantially affecting the T g values of the respective PET matrices. Notably, the T mc and ΔH mc values of the maximally extended PET (Trace 1, Figure 6(b)) increased by 4.3 C and 10.5 J g −1 , respectively, compared to that of PET (Trace 1, Figure 6(a)) and the values were further strikingly increased in the maximally extended PET ionomer (Trace 1, Figure 6(c)).…”

Sulphonated Biphenylated Poly(aryl ether ketone)s for Fuel Cell Applications

“…Kvalnes [13] reported the synthesis of p-biphenyl-hydroquinone in 1934, and no polymers except a polyester [14] was prepared based on this monomer. In a previous short communication [15], we reported MEA performance of a sulphonated biphenylated PAEK (BiPh-SPAEK) in order to study the relationship between the performance and the structure.…”