Mechanical properties of silica, graphite and carbon fiber reinforced composites

Abstract

The research aims to study the mechanical properties included impact strength and flexural strength of composite materials consists of epoxy resin with phenolic formaldehyde resin reinforced by graphite or silica particles or both, and reinforced with carbon fibers of a standard format (-90, 0, +90).The results obtained showed that the mechanical properties of epoxy-phenolic formaldehyde resins are enhanced after reinforced by silica, graphite and carbon fiber.Keyword -Epoxy, phenol formaldehyde resin, particles reinforcement, carbon fibers, mechanical properties I. INTRODUCTION Composite materials in this regard represent nothing but a giant step in the ever-constant endeavor of optimization in materials.Strictly speaking, the idea of composite materials is not a new or recent one.Nature is full of examples wherein the idea of composite materials is used [1].In the 20th century, modern composites were used in the 1930s when glass fibers reinforced resins.Boats and aircraft were built out of these glass composites, commonly called fiberglass .Since the 1970s, application of composites has widely increased due to development of new fibers such as carbon, boron, and aramids, and new composite systems with matrices made of metals and ceramics [2].Phenol formaldehyde resins is a type of polymer is made from two main substances: phenol and formaldehyde.Phenol is a colorless solid compound, but when exposure to oxidation in the air its colored by pink Then brown.It has strong odor and penetrating.Phenol is widely used in the manufacture of materials for plastics, including drinking water bottles, as well as in the clothing industry.Phenol is used in the installation of nylon.It has medical uses, it is used in the manufacture of disinfectants, lotions, ointments, topical anesthetics and the pharmaceutical industry [3].The water solution which contains a concentration of 40% formaldehyde is called formalin.this is used as a preservative for tissues and in embalming, with a boiling point of 21°C, it is used in veterinary and in dentistry as well as in the production of chemicals and polymers and is often used in the manufacture of coatings and explosives [4].In general, phenolformaldehyde produced by two ways, for manufacture two types of polymers, namely Novolac and Resole [5].Novolac is a type of polymers produced by mixing formaldehyde (37% water solution) with phenol by added an acidic helper (sulfuric, phosphoric or oxalic acid), and heated to the required degree and then equivalent the reaction mixture, and remove the water by distillation (in its final stages under discharge) to a temperature Estimated 160 ° C .Resole is a type is produced by added basic helper with more formaldehyde relative to phenol.Initially, its consists (Oligomer) is called a resole and it is not needed to a hardener (HMTA) but it need just heat treatment [3,6]. II. EXPERIMENTAL PROCEDURE Material used:The material used in this work are: (1) Epoxy resin LEYCO-POX 103, (2) phenol formaldehyde (resole) resin, (3) graphite particles, (4) silica particles, and (4) carbon fibers. Mixing process:The epoxy resin (80%) was mixed with phenol formaldehyde resin with the ratio (80:20)% as a matrix and the renforcing material was three types as shown in Table .1.TABLE I. Composition of composite