Studies of in-situ Compatibilized Blend of Silicone and EPDM Rubbers

1994 ◽  
Vol 67 (1) ◽  
pp. 119-128 ◽  
Author(s):  
Swapan Kole ◽  
Rabin Santra ◽  
Anil K. Bhowmick

Abstract The effect of three different compatibilizers — ethylene methylacrylate copolymer (EMA), ethylene vinyl acetate copolymer (EVA), and silane grafted polyethylene (VMX) — on the physical properties, ageing behavior, thermal stability, morphology, and dynamic mechanical properties of a 50/50 blend of silicone/EPDM has been studied. Improvement in physical properties is in line with the level of technological compatibilization. Strength of adhesion for silicone-EPDM joints is significantly enhanced by the compatibilizers due to the increase in surface energy of silicone and reaction of the rubbers with the compatibilizers. Morphology study shows smaller domain size for the compatibilized blend. Dynamic mechanical analysis also reflects strong interaction of the compatibilizer with the blend components. Ageing properties are improved with the addition of the compatibilizers. Thermogravimetric analysis indicates an increase in activation energy of degradation and hence marked improvement in the thermal stability of the blends containing compatibilizer.

2015 ◽  
Vol 744-746 ◽  
pp. 1374-1377
Author(s):  
Xi Wang

A nonlinear multifunctional polyamine N,N,N’,N’-tetra (3-aminopropyl)-1,6-diamino-hexane (TADH), was prepared and employed as a novel hardener for diglycidyl ether of bisphenol A (DGEBA). Nonisothermal reactions of DGEBA/TADH were systematically investigated with differential scanning calorimetry (DSC). In addition, analysis of thermal stability of the cured DGEBA/TADH with thermogravimetric analysis (TGA) revealed that it possessed quite good thermal stability and increased residual char content at 600◦C in nitrogen. Furthermore, dynamic mechanical analysis (DMA) of the DGEBA/TADH network showed its relaxations were characterized by localized motions of hydroxyl ether segments and cooperative motions of whole network chains (glass relaxation) at different temperature regions.


2002 ◽  
Vol 10 (5) ◽  
pp. 381-390 ◽  
Author(s):  
Viviane Xavier Moreira ◽  
Bluma Guenther Soares

Rubber blends containing nitrile rubber (NBR) and ground ethylene-vinyl acetate copolymer waste (EVAW) from the footwear industry have been prepared over a wide range of composition (up to 90 phr of waste component). The ground EVAW had particle size in the range of 100-350 mm and a gel content of 60±5%. The effect of different amounts of EVA waste on the tensile strength, elongation at break, hardness, tear strength and dynamic mechanical properties was studied. EVAW had a good reinforcing effect on the NBR matrix. A combination of optimum tensile properties, resistance to solvent penetration and dynamic mechanical properties, such as storage modulus and loss tangent was achieved by introducing 50 phr of EVAW in the NBR matrix. This composition also presents a more uniform morphology, as indicated by scanning electron microscopy.


2019 ◽  
Vol 39 (6) ◽  
pp. 508-514
Author(s):  
Yannan He ◽  
Zhiqiang Yu

Abstract The thermal and dynamic mechanical properties of epoxy composites filled with zirconium diboride/nano-alumina (ZrB2/Al2O3) multiphase particles were investigated by means of differential scanning calorimetry, dynamic thermo-mechanical analysis, and numerical simulation. ZrB2/Al2O3 particles were surface organic functional modified by γ-glycidoxypropyltrimethoxysilane for the improvement of their dispersity in epoxy matrix. The results indicated that the curing exotherm of epoxy resin decreased significantly due to the addition of ZrB2/Al2O3 multiphase particles. In comparison to the composites filled with unmodified particles, the modified multiphase particles made the corresponding filling composites exhibit lower curing reaction heat, lower loss modulus, and higher storage modulus. Generally speaking, the composites filled with 5 wt% modified multiphase particles presented the best thermal stability and thermo-mechanical properties due to the better filler-matrix interfacial compatibility and the uniform dispersity of modified particles. Finite element analysis also suggested that the introduction of modified ZrB2/Al2O3 multiphase particles increased the stiffness of the corresponding composites.


2011 ◽  
Vol 366 ◽  
pp. 306-309
Author(s):  
Ming Tao Run ◽  
Na Li ◽  
Bing Tao Xing ◽  
Meng Yao ◽  
Wen Zhou

The dynamic mechanical properties, phase morphology and thermal stability of the poly(trimethylene terephthalate)/maleinized poly(octene-ethylene)/organo-montmorillonite nanocomposites (PTT/POE/OMMT) were investigated by using the thermodynamic mechanical analyzer (DMA), transmission electron microscopy (TEM) and thermal gravimetric analyzer (TGA), respectively. The results suggest that the modulus of elasticity of the PTT/POE/OMMT nanocomposite increases, and the glass transition temperature first slightly decreases and then increases with increasing OMMT content because that the TPP plays the role of plasticizer and OMMT plays the role of reinforcing agent. OMMT disperse evenly in the polymer matrix with most of the strip-like sheet morphology. The addition of the OMMT does not apparently affect the thermal stability of the PTT/POE/OMMT nanocomposite.


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