The influence of short-term water storage on the flexural properties of unidirectional glass fiber-reinforced composites

Biomaterials ◽  
2002 ◽  
Vol 23 (10) ◽  
pp. 2221-2229 ◽  
Author(s):  
L.V.J. Lassila ◽  
T. Nohrström ◽  
P.K. Vallittu
2013 ◽  
Vol 734-737 ◽  
pp. 2230-2235 ◽  
Author(s):  
Fang Tian ◽  
Su Li Xing ◽  
Ying She Luo

Based on the experimental measurements of materials dielectric strength, this paper is focused on the relationships between dielectric strength of the materials and tensile stress applied on them. The experimental results indicated that the dielectric strengths of the unsaturated polyester resin and the unidirectional glass fiber reinforced composites had an obvious decrease compared with the samples without of it. Furthermore, the dielectric strength decreased with the increase of tensile stress. When tensile stress reached 50% of the material tensile strength, the dielectric strength of the resin decreased 13.36%, and the unidirectional glass fiber reinforced unsaturated polyester composites decreased 19.86% with the tensile stress in the longitudinal direction and 12.06% in the transverse direction. When the experimental samples were broken down by electricity, cracks and pores which would lead to stress concentration were created between the electrodes around the breaking-down point. In a word, it is vital to make a research about the effect of stress on the insulating properties of materials.


2021 ◽  
Vol 63 (3) ◽  
pp. 203-208
Author(s):  
Lingli Huang ◽  
Ruigang Hou ◽  
Yujian Liu ◽  
Qidong Shang

Abstract As fiber reinforced plastics (FRP) have been increasingly widely used, they may sometimes come into contact with several corrosive media simultaneously, for example, the condensate in the smokestack liners of coal-fired power FGD systems. To study the long-term performance and degradation mechanism of FRP in these complicated environments, an accelerated aging test of bromide epoxy vinyl ester (Br-VE) and its glass fiber reinforced composites (GF/VE) in a mixed acid solution(H2SO4, HNO3, HF and HCl) at three different temperatures(25, 55 and 80 °C) for 180 days was carried out. Weight changes, flexural properties, Fourier transforming infrared spectra (FTIR), dynamic thermal mechanical (DMA), macroscopic and microscopic morphology were investigated. Results showed that immersion temperature has important effects on the corrosion behavior of specimens. The long-term weight change behavior of GF/VE at normal temperature was in accordance with Fick’s second law, but deviated at higher temperature. Flexural properties of GF/VE declined more drastically than those of Br-VE at elevated temperatures. The Tg of GF/VE decreased with rising temperatures. Results also indicted that Br-VE and GF/VE manifested varied degradation mechanisms when subject to the same mixed acid medium immersion. The degradation of GF/VE mainly involved plasticization, embrittlement, the hydrolysis of resin, an ion exchange between HF, H+ and Si-O-Si or alkali metal of the fiber as well as the debonding of the resin/fiber interface.


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