Effects of Rubber Addition to an Epoxy Resin and Its Fiber Glass‐Reinforced Composite

Abstract

Epoxy resins are considered as one of the most important class of thermosetting polymers and find extensive use in various fields. However, these materials are characterized by a relatively low toughness. In this respect, many efforts have been made to improve the toughness of cured epoxy resins. In this work, samples of epoxy resin diglycidyl ether of bisphenol‐A and fiber glass‐reinforced composite of this polymer with and without liquid carboxyl‐terminated butadiene acrylonitrile (CTBN) copolymer were prepared to assess the effect of CTBN rubber on the properties of polymeric and composite laminate specimens. The addition of CTBN into the polymeric specimens led to a decrease in the glass transition temperature, fracture stress (from 70.39 to 56.34 MPa), and tensile elasticity modulus (from about 3.51 to 2.65 GPa), accompanied by an increase in elongation (from 2.47 to 5.64%). However, the degradation temperature of the polymeric system was not modified. Infrared analysis evidenced the occurrence of chemical reaction between the two components, and scanning electron microscopy results suggested rubber particles deformation as the prevailing toughening mechanism. The rubber addition in the composite specimens, promoted an increase simultaneous in fracture stress and in elongation at fracture. The elasticity tensile modulus has not changed. This probably results from the increased deformation capacity of the matrix, which prevents its premature cracking, and better adhesion between fibers and matrix observed in the CTBN‐modified composite laminates. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers

Mechanical and Tribological Behaviour of Hybrid Multi Fibre Reinforced Nylon 6-6 Nanocomposites

“…Even though the particles are surface-treated, the dense matrix medium makes the particles to settle in a place due to super saturation. Hence, poor energy absorption is found in higher particle loaded nylon 66 composite [25].…”

Fracture and toughening mechanisms of silica- and core–shell rubber-toughened epoxy at ambient and low temperature

“…The addition of a rubber [6][7][8], thermoplastic [9,10] or block copolymer phase [11] which is soluble in the resin but phase-separates during curing of the epoxy is commonly used to toughen epoxy polymers. Among these, a very successful approach has been the addition of carboxyl-terminated butadiene acrylonitrile (CTBN) rubber which phase-separates into micron-sized particles during curing [12].…”

“…An effective alternative to these phase-separating modifiers is to use pre-formed particles such as rubber [8], thermoplastic [14] or ceramic [17] particles which will increase the toughness without reducing the T g of the epoxy polymer. Such rubber particles are generally core-shell particles, with a soft rubbery core surrounded by a harder shell of polymethylmethacrylate [18].…”

Curing behavior and thermal and mechanical properties enhancement of tetraglycidyl-4,4′-diaminodiphenylmethane/4,4′-diaminodiphenylsulfone using a liquid crystalline epoxy

“…However, wider usage of epoxy resins has been limited because of their intrinsic brittleness, water absorption and so on. To overcome this problem, the concept of polymer incorporation involving the modification of epoxy resins with carboxyl‐terminated copolymers of acrylonitrile and butadiene, block copolymer thermoplastics, liquid rubber, and so forth has become popular . As far as the toughness is concerned, this is a good method but usually results in an accompanying reduction in modulus and poorer thermomechanical properties due to incorporation of a more flexible network structure, or a phase separation in the modified resin system.…”