Effect of Water on Some Mechanical Properties for Sawdust and Chopped Reeds /UPE composites

Abstract

In this study, composite materials were prepared using unsaturated polyester resin as binder with two types of fillers (sawdust and chopped reeds). The molding method is used to prepare sheets of UPE / sawdust composite and UPE / chopped reeds composite. The mechanical properties were studied including flexural strength and Young's modulus for the samples at normal conditions (N.C). The Commercial wood, UPE and its composite samples were immersed in water for about 30 days to find the weight gain (Mt%) of water for the samples, also to find the effect of water on their flexural strength and Young's modulus. The results showed that the samples of UPE / chopped reeds composite gained highest values of flexural strength (24.5 MPa) and Young's modulus (5.1 GPa) as compared with other composites at (N.C). The results showed that the wet samples of sawdust composite have lowest values of weight gain (Mt %) of water (0.043%) as compared with other composites after immersion. Also it’s showed a slight decrease in values of Young's modulus for all the samples after immersion as compared with the samples at (N.C). Finally it’s showed a slight decrease in values of flexural strength for all the samples except for the composite material formed from UPE / chopped reeds which showed an increase in the value of flexural strength after immersion, where the wet samples of UPE / chopped reeds composite gained (29 MPa) as compared with the samples at (N.C).

Study of Bending Property for Epoxy / Kevlar - Glass Fibers and Hybrid Composite

“…Stress constantly from top to bottom expanding (craze) to lead to (crack) starting from the bottom surface of the sample and spread toward the upper surface of the sample, leading to the break. The reason is due to the fact that the polymeric chains consisting of the sample are intertwined, when you shed the stress on the sample will lead to the occurrence of landslides in the polymeric chains and move those chains in various directions until the occurrence of break-up [9] , while the composite samples show a different behavior according to the type of fiber although they where common to have a linear behavior initially and after noted displacement, where the curve began to fluctuate as shown in Fig. (3,4).…”

“…Epoxy resin type (Quick mast 105) was provided by DCP Company / Jordan with specific gravity (1.04) is used with its hardener in ratio (1:3).The epoxy was mixed with a hardener in a container to form a mixture was used to prepare composites. The volume fraction of matrix and reinforcement material is calculated from the following equations [9]. Volume fraction of matrix:…”

Preparation and study Impact and Hardness Strength for Gravel Nano Particles /Polyester Composites

“…This process, known as cross linking, so that the composite materials have chemical resistance, higher mechanical properties and greater structural durability than thermoplastics. [5]Young and Beaumont [6], group of researchers [7], Sewench and Najlaa [8], Hanaa [9] and Wasan [10] studied silica powder, wood flour and rice husk,coconut shell particulates, zinc oxide& Aluminum oxide and particles of glass based composite respectively.…”