Effects of plasticizer on structures, non‐isothermal crystallization, and rheological properties of polyarylates

Abstract

We herein report the effects of plasticizer content (1–5 wt %) on the structure, non‐isothermal crystallization kinetics, thermal stability, and rheological property of a new type of multicomponent polyarylate (PAR). Fourier transform infrared spectra reveal the presence of a specific interaction between plasticizer and PAR chains, indicating the good dispersion of the plasticizer at the molecular level. The plasticizer influences on the non‐isothermal crystallization behavior of the PAR in two different ways: a mobility enhancer of PAR chains and an impurity to the crystallization of PAR. The melt‐crystallization temperature (Tmc) and enthalpy (ΔHmc) of the plasticized PARs at cooling runs are higher than those of the neat PAR, which is owing to the enhanced mobility of PAR chains by the plasticizer. On the other hand, the non‐isothermal crystallization rates at different cooling rates of 5–40 °C/min are slower for the PARs with higher plasticizer contents, which is due to the impurity effect of the plasticizer on the melt‐crystallization of PARs. Although the PARs with 1–5 wt % plasticizer have lowered thermal decomposition temperatures, compared to the neat PAR, they are thermally stable up to ∼400 °C. The complex melt viscosity of PAR with only 1 wt % plasticizer is far lower than that of the neat PAR. Overall, it is found that only 1 wt % plasticizer is quite effective to facilitate the melt‐processibility and to increase the crystallinity of PAR. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45704.

Construction of strong non‐covalent interactions for preparation of flame‐retarded acrylic pressure‐sensitive adhesives with improved shear and peel strengths

“…The reason is that the relatively high crystallinity, as evidenced by the sharp diffraction peak (see in Figure 5b). As a colorless liquid small molecule plasticizer, DMMP has good compatibility with acrylic PSAs and is able to easily diffuse into the polymer matrix to achieve uniform dispersion, and affects the crystallization behavior of flame‐retarded acrylic PSAs in two ways 33 . On the one hand, DMMP decreases the intermolecular hydrogen bonding strength of A35 as evidenced by the decreased T g values, leading to increased mobility of polymer chains and enhanced crystallinity.…”

Effects of Poly(ethylene-co-glycidyl methacrylate) on the Microstructure, Thermal, Rheological, and Mechanical Properties of Thermotropic Liquid Crystalline Polyester Blends

“…To characterize the crystalline features of TLCP/PEGMA blends, X-ray diffraction patterns of neat TLCP, neat PEGMA, and their blends were obtained, as can be seen in Figure 5 . For neat TLCP, a typical diffraction peak at ~19.8°, which corresponds to d -spacing of 4.5 nm based on Bragg’s law, was observed and this is associated with the (110) plane of the TLCP crystalline structure [ 4 , 32 ]. In the case of PEGMA, strong diffraction peaks can be observed at 21.3 and 23.3°, which correspond to the (110) and (200) planes of PE crystals, respectively [ 33 ].…”

“…Thermotropic liquid crystalline polyesters (TLCPs)—aromatic polyesters exhibiting liquid crystallinity in a molten state—are used in a variety of industrial sectors because of their excellent thermal stability, dimensional stability, mechanical performance, and chemical resistance [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ]. Since TLCPs can be processed easily due to their low viscosity as a result of their ordered melt, an extremely high molecular orientation can be attained in fibers, films, and injection molded parts.…”

Synthesis and properties of copolyarylates containing phenol red units

“…The molecular structures of the co‐PARs were characterized by 1 H NMR spectrometer(Bruker 400 M, Germany) using deuterated chloroform (CDCl 3 ) as the solvent. The composition of the copolymer was quantitatively measured using the integrated areas (S 1 , S 6 ) of the two chemical shifts at δ = 1.74 and 7.44 ppm.…”

“…Polyarylate is a high‐performance thermoplastic special engineering plastic, which has high strength and high modulus, 1 excellent thermal stability, 2 chemical resistance, 3 optical properties, 4,5 and low dielectric constant, 6 which are well used in aerospace, medical devices, 5G materials, gas separation membranes and other fields 7–9 . However, due to the regular chain structure, the high melting temperature of polyarylates leads to poor processing fluidity 10 .…”