Influence of carboxyl‐terminated (butadiene‐co‐acrylonitrile) loading on the mechanical and thermal properties of cured epoxy blends

Abstract

A mixture of epoxy with liquid nitrile rubber, carboxyl‐terminated (butadiene‐co‐acrylonitrile) (CTBN) was cured under various temperatures. The cured resin was a two‐phase system, where spherical rubber domains were dispersed in the matrix of epoxy. The morphology development during cure was investigated by scanning electron microscope (SEM). There was slight reduction in the glass transition temperature of the epoxy matrix (Tg) on the addition of CTBN. It was observed that, for a particular CTBN content, Tg was found to be unaffected by the cure temperature. Bimodal distribution of particles was noted by SEM analysis. The increase in the size of rubber domains with CTBN content is due probably to the coalescence of the rubber particles. The mechanical properties of the cured resin were thoroughly investigated. Although there was a slight reduction in tensile strength and young's modulus, appreciable improvements in impact strength, fracture energy, and fracture toughness were observed. Addition of nitrile rubber above 20 parts per hundred parts of resin (phr) made the epoxy network more flexible. The volume fraction of dispersed rubbery phase and interfacial area were increased with the addition of more CTBN. A two‐phase morphology was further established by dynamic mechanical analysis (DMA). © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2531–2544, 2004

Development and characterization of composite materials for production of composite risers by filament winding

“…Phase separated rubber domains occupy the regions between the reaction centers, blocking the cross-linking reaction in these centers. Similar observations have been reported by many authors using different rubbers [11][12][13][14][15][16] . As expected, the tensile modulus also decreased with addition of CTBN, from 3.45 to 2.75 GPa.…”

“…This is attributed to the dissolution of CTBN into the polymeric network. Previous works on rubber-modified epoxy support this observation 11,[13][14][15][16]27,34 .…”

“…The same reasons can explain the increase of the strain and toughness at fracture. It was observed in many studies [11][12][13][14][15][16] that the tensile modulus decreases with increasing rubber content.…”

Synthesis of Benzene Tetracarboxamide Polyamine and Its Effect on Epoxy Resin Properties

“…The addition of BTCP led to a slight decrease in T g , which is attributed to an increase in the amount of dissolved BTCP within the epoxy matrix. This behavior was also observed in other rubber-or elastomer-modified epoxy systems [25][26][27]. Figure 6 shows the results of the thermomechanical analysis (TMA) of the compositions, the data for which are presented in Table 4.…”

The Physical Properties Analysis of Epoxy Resins Incorporated with Toughening Agents

“…대표적으로 고무 계열 및 열가소성 재료를 에폭시 수지에 도입하 여 강인성 향상을 도모하는 방법들이 주로 소개되어 진다 [7,8]. 에폭시 수지의 강인성 향상을 위해 주로 사 용되는 소재는 carboxyl-terminated butadiene-co-acrylonitrile (CTBN), amine-terminated butadiene-co-acrylonitri le (ATBN), 폴리부타디엔(polybutadiene), 폴리우레탄(polyurethane), 코어/쉘 나노입자(core/shell nanoparticle), poly ethylene oxide (PEO), 폴리아마이드(polyamide) 등이 있 으며, 이 중에서 CTBN과 ATBN은 에폭시 수지와의 반응을 통해 변성에폭시의 형태로 합성하여 주로 사 용되고 있다 [9].…”