ABSTRACT

Short length fibres were incorporated into ortho unsaturated polyester resin. The treated and untreated fibre composite samples were subjected to tensile, flexural and micro hardness tests according to ASTM D638 using Intron model 3369. The tensile tests include tensile strength, modulus, loadatbreak, tensile strainatbreak and extensionatbreak while the flexural tests include flexural strength, flexural modulus and flexural load at yield.

Thermal conductivity, electrical conductivity, water absorption tests and scanning electron microscopy SEM also carried out. The significant findings of the research showed that treatment improved the tensile, flexural and micro hardness properties except for flexural load at yield where the untreated fibre composites were observed to exhibit better properties. The tensile properties at 10 fibre load were greatly enhanced. 20 fibre load gave the maximum flexural modulus and flexural load at yield while 10 fibre load was best for good flexural strength. 15 fibre load was best for micro hardness. Furthermore, there was no appreciable difference in thermal conductivities of the composites. The electrical conductivites of the pretreated fibre composites were significantly higher than that of the untreated fibre composites, water absorption was significantly reduced by the pretreatment while the scanning electron micrographs showed that the composites of the alkali treated fibre were more homogenous indicating better wettability of fibre and matrix and thus having less voids for water absorption.

CHAPTER ONE

1.1 Introduction

Fibre Reinforced Polymer FRP is a relatively new class of composite

material manufactured from fibre and resin. It has proven efficient and

economical for use in variety of engineering applications in different field

such as aerospace, oil, gas and process industries as per the strategic

engineers piping manual Yu et al., 2006. Composite materials exhibit good

resistance to temperature extremes and wear, especially in industrial settings.

The tailorability of composites for a specific purpose has been one of its

greatest advantages and also one of the more perplexing challenges to

adopting them as alternative materials to metallic ones Asasutjarit et al.,

2007.

Fibre reinforced polymer composites use polymers either thermoplastics or

thermosets, as matrix and fibres of various types as reinforcement. The

fibres provide increased stiffness and tensile capacity giving them their

mechanical characteristics. The resin offers high compressive strength and

binds the fibres into a firm matrix. Furthermore, many of our technologies

require materials with unusual combination of properties that cannot be met

by the conventional metal alloys. The mechanical properties of fibre ...Get Complete Material.