共查询到20条相似文献,搜索用时 95 毫秒
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研究了氢氧化镁、氧化锌及硬脂酸对环氧化天然橡胶(ENR)硫化特性、硫化胶的力学性能及老化性能的影响。结果表明:加入2份氢氧化镁可有效地提高ENR的硫化速度、拉伸强度和抗热氧老化性能;氧化锌和硬脂酸对硫化胶网络的完善是不可缺少的。用差示扫描量热法(DSC)比较了几种防老剂(防老剂D,H.WSP,MB.4010,SP)在ENR中的防护效果。结果表明防老剂D的效果最好。以防老剂D与防老剂MB并用,加入2份氢氧化镁、2份硬脂酸和5份氧化锌,不仅可缩短硫化时间,而且可大幅度提高硫化胶的拉伸强度、扯断伸长率和老化系数。 相似文献
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环氧化天然橡胶贮存性能的差异 总被引:3,自引:0,他引:3
对环氧化天然橡胶(ENR)及其胶乳(ENRL)进行了为期2年的贮存试验,考察其外观和主要物理性能的变异状况,探讨了这些性状变异的机理,了解到ENR和ENRL原材料长期贮存,其外以观无明显变化。 相似文献
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天然橡胶与环氧化天然橡胶并用硫化胶的相结构及其物理性能 总被引:1,自引:0,他引:1
研究了天然橡胶(NR)与环氧化天然橡胶(ENR)并用胶的相结构对并用胶性能的影响。并用动态力学分析和电子显微照片分析了并用胶的结构。动态力学分析和电子显微照片表明,不同配比的NR/ENR并用胶具有多相结构,且在ENR的何种分数接近0.35时产生共连续相转换。相结构对并用胶的气密性和耐油性有很大影响。 相似文献
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Polymeric antioxidants can be useful in the protection of styrene-butadiene rubber (SBR) against thermal oxidative aging as an alternative to the low molecular weight ones, which migrate out of the rubber articles. Three polymeric compounds were prepared and incorporated into SBR mixes to be evaluated as antioxidants in comparison with the commercial antioxidant, N-isopropyl-N′-phenyl-p-phenylenediamine (IPPD). The rheometric characteristics of the produced SBR mixes were measured and the cure time was determined. The mechanical, swelling, extraction, and compression properties were studied. The results obtained revealed that poly(4-mercaptophenyl)acrylamide has superior effect in the protection of SBR articles against thermal oxidative ageing. 相似文献
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《国际聚合物材料杂志》2012,61(8):783-794
ABSTRACT The thermal stability was investigated for ethylene propylene diene terpolymer (EPDM) rubber loaded with different white and black fillers, namely, kaolin, quartz, polyvinylchloride PVC, talc, graphite, medium thermal carbon black MT, semi reinforcing furnace black SRF, and high abrasion carbon black HAF. The fillers were added at a fixed level of 20 phr. Two curing systems were used, tetramethyl thiuram disulfide (TMTD) and sulfur/N-cyclohexyl-2-benzothiazyl sulfenamide (S/CBS). The effects of the curing system and type of filler on the physico-mechanical properties, before and after thermal aging were investigated. It was found that the vulcanizates cured with S/CBS system gave better physico-mechanical properties than the TMTD cured samples. However, TMTD cured EPDM has thermal stability performance superior to the other vulcanizing system. 相似文献
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不同聚醚由于其下游应用需求不同,对抗氧剂的需求也不同。普通软泡聚醚在发泡应用时由于发泡配方中含水量高,发泡温度比较高,泡沫的烧芯问题是抗氧剂要解决的关键问题,U-pack B7033可以满足应用需求;对于高回弹聚醚,由于其主要应用是汽车领域,除了考虑泡沫的抗烧芯性能外,还要考虑添加的抗氧剂对聚醚及聚氨酯泡沫的醛酮含量以及VOC的影响,U-pack B7170可以满足应用要求;CASE聚醚用抗氧剂除了要考虑聚醚的储存稳定性外,还要考虑下游制备聚氨酯预聚体时的颜色稳定性,U-pack B7522可以满足应用要求。 相似文献
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M. N. Ismail 《Polymer-Plastics Technology and Engineering》2013,52(6):751-758
Seven organo-phosphorus compounds were synthesized and incorporated in natural rubber (NR) and styrene-butadiene rubber (SBR) mixes. The rheometric characteristics of the green rubber mixes were determined using the oscillating disc rheometer. The prepared compounds were evaluated as thermal stabilizers and antifatigue agents in NR and SBR vulcanizates. The results revealed that the prepared compounds were good antioxidants and antifatigue agents for rubber vulcanizates exceeding the commercial antioxidant 4-methyl-2,6-di-tert-butyl phenol, which is used in the rubber industry. In addition, the efficiency of such compounds depends on their chemical structure. 相似文献
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《国际聚合物材料杂志》2012,61(12):1095-1114
Physico-mechanical, aging, swelling, solubility, and permeability properties of blends of natural rubber and thioglycollic acid modified epoxidized low molecular weight natural rubber (TGA-ELMWNR) filled with admixtures of carbon black and carbonized rubber seed shell (CRSS) in ketones, alcohols, aldehydes, and petroleum fuels (petrol, kerosene, and diesel) were investigated as a function of different filler composition. The physico-mechanical properties were found reducing as the level of CRSS increases, but were within the accepted level for natural rubber compounds, showing that CRSS can find uses as fillers in materials of low tensile strength. The aging results of all the mixes were nearly of the same magnitude. The swelling and solubility results showed that ketones swell the vulcanizates more and faster than alcohols and than aldehydes. The sorption, diffusion, and permeability of the blends as determined by the gravimetric method confirm the better resistance of blends with higher ratio of carbon black. Petrol was found diffusing through the vulcanizates faster than kerosene and faster than diesel. Above all, replacement of carbon black with 15% carbonized rubber seed shell has not shown any serious deleterious effects on the vulcanizates. 相似文献
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探讨了三元乙丙橡胶(EPDM)和环氧化天然橡胶(ENR)的共混比、加料顺序、硫化体系对EPDM/ENR共混物的硫化特性、力学性能和耐热空气老化性能的影响。结果表明,共混比不同,共混胶的性能均有差异,且共混物的力学性能低于单组分的线性加和值,但综合比较而言,当EPDM/ENR=40/60时共混胶的力学性能较好;在所研究的四种加料顺序中,以配合剂先与EPDM制成母炼胶后再与ENR共混的这一种加料顺序下所得的共混物硫化胶的力学性能最好;采用半有效硫化体系所制得的共混物硫化胶的力学性能较好。 相似文献
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研究了Si69系列的硅烷偶联剂对NR胶料力学性能和耐磨性能的影响。试验结果表明,硫原子数影响力学性能和耐磨性,但基本上不影响它们随硫化时间下降的趋势。另外,硫原子数对力学性能和耐磨性、以及耐磨性随硫化时间下降趋势的效应填充体系(炭黑、炭黑、/白炭黑)而异。 相似文献
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《Polymer-Plastics Technology and Engineering》2013,52(5):1323-1344
Abstract Comparison studies on effects of feldspar and silica (Vulcasil C) as a filler in (SMR L grade natural rubber) vulcanizates on curing characteristics, mechanical properties, swelling behavior, thermal analysis, and morphology were examined. The incorporation of both fillers increases the scorch time, t 2, and cure time, t 90, of SMR L vulcanizates. At a similar filler loading, feldspar exhibited longer t 2 and t 90 but lower values of maximum torque, MHR, and torque difference, MHR–ML than did silica-filled SMR L vulcanizates. For mechanical properties, both fillers were found to be effective in enhancing the tensile strength (up to 10 phr), tensile modulus, and hardness of the vulcanizates. However, feldspar-filled SMR L vulcanizates showed lower values of mechanical properties than did silica-filled SMR L vulcanizates. Swelling measurement indicates that swelling percentages of both fillers-filled SMR L vulcanizates decrease with increasing filler loading whereas silica shows a lower swelling percentage than feldspar-filled SMR L vulcanizates. Scanning electron microscopy (SEM) on fracture surface of tensile samples showed poor filler–matrix adhesion for both fillers with increasing filler loading in the vulcanizates. However, feldspar-filled SMR L vulcanizates showed poorer filler–matrix adhesion than did silica-filled SMR L vulcanizates. Thermogravimetric analysis (TGA) results indicate that the feldspar-filled SMR L vulcanizates have higher thermal stability than do silica-filled SMR L vulcanizates. 相似文献