Effect of thermal aging on crystallization behaviors and dynamic mechanical properties of glass fiber reinforced polyphenylene sulfide (PPS/GF) composites

Abstract

In this study, the main purpose is to systematically evaluate isothermal and non-isothermal crystallization behavior of short glass fiber-reinforced polyphenylene sulfide polymer composites (PPS/GF) by a wide range of commonly applied models and also to preciously discuss the crystallization evolution and dynamic mechanical properties together with the consideration of thermal aging effects. Some interesting progress concerning this study can be concluded as follows: the Avrami model was used to examine the isothermal crystallization behavior of PPS/GF and the Avrami plot results exhibit that the isothermal crystallization contains primary and second crystallization process. In terms of non-isothermal crystallization, the Jeriorny model and Mo model could describe the mechanism of nucleation and crystal growth of PPS/GF material under study. Also, the activation energy of non-isothermal crystallization is calculated (−58.78 kJ/mol) by Kissinger method. Another important aspect is that thermal aging has an obvious effect on crystallization behaviors of PPS under study. The degree of crystallinity increases from 44% (virgin sample) to 56% after 96 h of aging at 200°C. After a long period of oxidation up to 1080 h at 200°C, the crystallinity degree decreases to 36.6% due to thermo-oxidation effect. DMA results imply that thermal aging may lead to more crosslinking reactions and result into more restriction of molecule mobility in PPS composite materials.

Heterogeneous Multi UAV Mission Planning Based on Ant Colony Algorithm Powered BP Neural Network

“…In the research of path planning for multiple UAVs, researchers proposed an algorithm in the form of decision tree [ 4 ]. Elhousari et al used a new method to solve the model and tested the optimization degree of the algorithm based on multiple data sets [ 23 ]. An algorithm that solves the task path planning problem of multiple UAVs was proposed in [ 24 ].…”

Thermal aging performance of glass fiber/polyphenylene sulfide composites in high temperature

“…However, the smooth surface of glass fibers is observed in GF/PPS composites aged for above 168 h. It indicates that there are obvious separation between fiber and matrix in the GF/PPS composites aged for long time in high temperature. Therefore, the reduction of tensile strength of aged GF/PPS composites is attributed to the decreased interfacial adhesion between resin matrix and glass fiber due to the degradation of PPS resin 60–63,65,66 …”

“…However, there are few literatures discussing about the effect of long time in high temperature on the physical, thermal, and mechanical properties of GF/PPS composites. Zuo et al 60–63 systematically investigated the physical, thermal, and mechanical properties of thermally aged GF/PPS composites and observed the obvious degradation of PPS composites aged at 180 and 200°C and the increase in thermal oxidation layer from outside to inside during the aging period in oven. The results of isothermal and non‐isothermal crystallization behaviors and dynamic mechanical properties of thermal aged GF/PPS composites indicated that the thermal aging has an obvious effect on crystallization behaviors of PPS composites.…”

Optimization of molding process parameters for CF/PEEK composites based on Taguchi method

“…10 Xu et al found that if the materials were held at high temperatures for an excessive time, the polymer matrix would degrade, thus would affect the mechanical properties of the materials. [11][12][13] Gao and Kim pointed out that the crystallinity of the polymer matrix was related to the cooling rate. The performance of the material was affected by crystallinity to a large extent.…”