Kinetics of water absorption and hygrothermal aging rubber toughened poly(butylene terephthalate) with and without short glass fiber reinforcement

Abstract

ABSTRACT:The objectives of this paper were to investigate the water absorption and hygrothermal aging behavior of rubber-toughened poly(butylenes terephthalate) (RT-PBT) with and without short glass fiber (SGF) reinforcement. The rubbers used in the study were AX8900 and EXL2314, both of which are acrylate-based terpolymer. The effect of the hygrothermal aging on its fracture properties was also studied. The kinetics of the water absorption study were carried out on the injection-molded samples of the RT-PBTs and the SGF-reinforced rubber-toughened PBT (SGF-RT-PBT) at three immersion temperatures, 30, 60 and 90°C, for a total of 450 h. The study of the deterioration caused by the hygrothermal aging was conducted by investigating the fracture parameters and flexural properties of all the materials as both hygrothermally aged (HA) and redried state (RD). The modes of the failure of HA and RD samples were studied using the scanning electron microscopy (SEM) technique. It was found that all the samples conformed to Fickian behavior and the kinetics of absorption exhibited a strong dependency on the rubber types, presence of SGF, as well as the immersion temperature. Generally, SGF-RT-PBT showed a better resistance to hygrothermal aging than that of RT-PBT and PBT, though a declining trend was observed in the fracture parameters, K c and G c . However, an opposite observation was exhibited in the flexural properties in some, but not all cases. Finally, the results obtained from SEM micrographs showed that permanent damage occurred in the materials and the hygrothermal aging had suppressed the plastic deformation ability of the PBT matrix and both types of impact modifiers where brittle failure was observed. Fiber pull-out was apparently the failure mode of the SGF-reinforced materials.

Dynamic Moduli of Polybutylene Terephthalate Glass Fiber Reinforced in High-Temperature Environments

“…Incorporating elastomeric materials increases fracture tenacity, performance upon impacts, and components' surface resistance by, in turn, increasing the retention and recovery capacities of the material's properties, even after aging processes [24][25][26][27]. The improvement is attributed to local deformation zones being produced, which act as energy dissipaters and would, thus, increase the plasticity of the analyzed samples.…”

NaBF4 as a hygrothermal durability enhancer for glass fibre reinforced polypropylene composites

“…6), which lessened the efficiency of stress transfer of the interphases. In the case of aged PPC-00, the nearly intact σ is similar to that of rubber toughened semi-crystalline polymers [26] and -10 -most likely related to the embrittlement of PE regions, since less plastic yielding of matrix was observed on the fracture surfaces (Fig. 7).…”

Dynamics of Changes in Mechanical Properties of Polybutylene Terephthalate and Polybutylene Terephthalate-Polyethylene Compositions in Aggressive Liquid Media

“…It should be noted that hydrolysis in distilled water is very slow, and acids and bases of various concentrations are added to accelerate it. Therefore, changes in physical and chemical properties of polymers interacted with aggressive media, even for unloaded materials, are considered approximated to natural operating conditions [6][7][8][9][10].…”