Effect of modified silicone elastomer particles on the toughening of epoxy resin

Silyl-crosslinked urethane elastomer modifying epoxy resin has drawn much interest. Here the triethoxysilyl-terminated polycaprolactone elastomer (PCL-TESi) modifying diglycidylether of bisphenol A epoxy resins (DGEBA) system was chosen, and then the effect of the type of curing agent on the phase structure of the studied epoxy resin system was investigated. The modified systems were obtained with different phase structures by varying the formulations of the curing agent. It was experimentally shown that with the addition of aminosilane (KBE-9103), the crosslinked density was greatly increased. The cured system also showed from SEM and TEM analysis that addition of KBE-9103 increased the compatibility between the PCL-TESi and DGEBA, which made the ductility of the system decrease, but also indicated from TEM that addition of much KBE-9103 made the reacted silicone particles coagulate each other. The state of phase separation from TEM in the cured system was theoretically explained. These would serve the deeper studies of the mechanism of silyl-crosslinked urethane elastomer modifying epoxy resin in the future.

Section: Effect Of the Kbe-9103/kb-2 Formulation On The Change In Mormentioning

confidence: 99%

Section: Effect Of the Kbe-9103/kb-2 Formulation On The Phase Structumentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Morphology of epoxy resin modified with silyl‐crosslinked urethane elastomer

Liu¹,

Lin²,

Ding³

et al. 2005

“…Epoxy resins have been widely used for adhesives, paints, and molding compounds in the civil engineering, construction, automobile, and electronic material fields because cured epoxy resins show good adhesion strength, stiffness, thermal durability, and mechanical and electronic properties. Cured epoxy resins had lacked the properties of toughness and peel adhesion, but these have been improved through various investigations, which have typically utilized a polymer blend technique using a reactive elastomer or various types of polymer, such as carboxyl‐terminated butadiene acrylonitrile rubber (CTBN),1–14 acrylic core–shell particles,14–20 and crosslinked urethane microsphere or silicone elastomer 21–25. These investigations have focused on enhancing toughness without losing the other advantages of cured epoxy resins.…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, the cured system has a phase‐separated structure with the DMSi–PPO network as the matrix phase reinforced by dispersing DGEBA microparticles. There are reports in the literature on the relationship between adhesion strength and the phase structure of the DMSi–PPO/DGEBA system against an aluminum substrate 26–27. We had previously raised concerns about the adhesion strength and interfacial chemistry of a DMSi–PPO/DGEBA blended system against some polymeric materials that have a lower surface free energy than the metal substrates.…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic work of adhesion and peel adhesion energy of dimethoxysilyl‐terminated polypropylene oxide/epoxy resin system jointed with polymeric substrates

Okamatsu

Yasuda

Ochi

2001

Self Cite

ABSTRACT:The characterization of the interfacial surface of a dimethoxysilyl-terminated polypropylene oxide (DMSi-PPO)/diglycidylether of bisphenol A (DGEBA) system, which has the phase structure of DGEBA particles in a DMSi-PPO matrix, was investigated by using model joints with polymeric substrates. The surface free energy (␥) of the DMSi-PPO/DGEBA system had varied with the ␥ of each substrate. When the system contacted to low surface free energy materials such as Teflon, polypropylene, and polyethylene, the ␥ of the system showed about 14.3-31.6 mJ/m 2 ; on the other hand, when the system contacted to high surface free energy substrates such as polyethylene-telephthalate and polyimide, the ␥ of the system showed 50.4 and 64.6 mJ/m 2 , respectively, because the concentration of the DGEBA as a polar component in the system changed around these interfaces. In the low surface energy substrates used, the actual peel adhesion energy value was in good agreement with the thermodynamic work of adhesion (Wa) determined independently. However, in the high surface energy materials used, the peel adhesion energies were 10 3 -10 4 times larger than Wa because the energy was dissipated viscoelastically at the jointed points.

Properties and toughening of heat‐resistant thermosets based on unsaturated ester resins

Canelas

Abbey

Fentress

2002

ABSTRACT:We describe our investigations of the curing chemistry and properties of heat-resistant thermosets comprised of unsaturated ester resins. We suggest a mechanism for the rearrangement of the cured matrix and volatile evolution during the curing process. We employed dielectric spectroscopy (DES) as a tool for monitoring the extent of cure, determining glass-transition temperatures, and evaluating electrical properties of the resins. We compare and contrast results obtained by DES to results obtained by dynamic mechanical analysis (DMA). Fracture testing showed that improvements were made in the toughness of these materials by blending the uncured resin with impact modifiers such as hydrocarbon or silicone reactive rubber adducts or poly(arylene ether sulfone)-based thermoplastic oligomers. We determined the effects of the thermoplastic toughening additive's molecular weight, concentration, and endgroup functionality on the phase separation, thermal stability, and fracture toughness of the blend.