Young's Modulus of Vinyl Ester Composites Cured by Microwave Irradiation: Preliminary Results

Abstract

Abstract:The shrinkage of vinyl ester particulate composites has been reduced by curing the resins under microwave conditions. The reduction in the shrinkage of the resins by microwaves will enable the manufacture of large vinyl ester composite items possible [1][2][3][4]. The difference in impact strength between microwave cured vinyl ester particulate composites and those cured under ambient conditions had been investigated and found to be minimal [5]. In addition, a previous study found that the difference in fracture toughness obtained by short bar method between selected microwave-condition cured vinyl ester particulate composites and those cured under ambient conditions was only 0.5% [6]. This project is to investigate the difference in Young's modulus, ultimate tensile strength and yield strength between microwave cured vinyl ester particulate composites and those cured under ambient conditions.The results show that the difference in the Young's modulus is minimal.

Yield and Tensile Strength of Vinyl Ester Composites Cured by Microwaves

“…The results also show that microwave cured composite samples will result in smaller shrinkage with the similar values of mechanical properties mentioned above than those samples cured under ambient conditions [1]. The reduction in the shrinkage of the resins by microwaves will enable the manufacture of large vinyl ester composite items possible.…”

“…The 1.8 kW power is actually achieved by launching microwaves from two 0.9-kW magnetrons. The power inputs can be varied from 10% (180 W) to 100% (1800 W) in steps of 180 W. In this project, VE/FLYASH (33%) was exposed to microwave irradiation of 180 and 360 W with exposure of duration from 30 to 50 seconds as recommended in the previous studies [1,7].…”

“…The reinforcer was fly ash (ceramic hollow spheres) particulate and its percentage by weight was 33% in the cured vinyl ester composite, VE/FLYASH. Thirty three percent by weight of fly ash particulate reinforced vinyl ester resin, VE/FLYASH (33%), is used for the study because it is exactly the same material used in the previous relevant † Also with Centre of Excellence in Engineered Fibre Composites, University of Southern Queensland, Australia study as well as that used by Centre of Excellence for Engineered Fibre Composites (CEEFC) of the University of Southern Queensland (USQ) to make composite components for regional governments and industries [1,[3][4][5][6][7]. Australian Standard 1145.2 -2001 is used as the basis for determining the tensile properties of the composites [8].…”

Processing of Composites Using Variable and Fixed Frequency Microwave Facilities

“…A Shimadzu tensile testing machine was used for the lap shear test. A load range of 2000 N and a load rate of 600 N per minute were selected for the test [13][14][15][16]. Figure 7 shows the lap shear strength of PS/GF (33%) joined by a fixed frequency microwave facility in a slotted rectangular waveguide.…”

Tensile Tests of Phenol Formaldehyde SLG Reinforced Composites: Pilot Study

“…The gauge length used should be the separation of the grips and 105 mm because the elongation of non-ductile material, e.g. this phenolic composite, when subjected to tensile force will spread along the sample evenly and not restricted to the conventional gauge length of 50 mm [9,10]. Figure 1 also illustrates how the 0.1 % proof load was determined.…”