NR/ENR并用胶的性能研究

探讨NR/环氧化天然橡胶（ENR）并用比对NR/ENR并用胶性能的影响。结果表明,NR/ENR并用胶为部分相容体系；并用胶硫化特性和物理性能与NR基本一致,耐热空气老化性能和动态压缩疲劳性能有所下降；当ENR用量较小（10份）时,并用胶抗湿滑性能提高,同时滚动阻力降低。     

除臭菌株对NR动态力学性能的影响

采用RPA2000橡胶加工分析仪,分析了不同凝固方式获得的NR的动态力学性能。结果发现,除臭菌株C5对生物凝固胶的动态力学性能无不良影响,且加有除臭菌株C5的生物凝固胶块具有比生物凝固和酸凝固更好的加工性能和回弹性。     

UFPCSBR/n-SiO_2纳米粉末材料改性NR/SBR复合材料性能的研究

研究了超细全硫化羧基丁苯橡胶/纳米二氧化硅(UFPCSBR/n-SiO2)纳米复合粉末材料的表面形貌及其对NR/SBR复合材料硫化特性和力学性能的影响。结果表明,UFPCSBR颗粒和n-SiO2颗粒在纳米复合粉末材料中分散良好;加入14份纳米复合粉末材料(UFPCSBR/n-SiO2质量比为3/4)赋予了NR/SBR复合材料较好焦烧安全性,可显著改善100%定伸应力和300%定伸应力,并且拉伸强度、撕裂强度和拉断伸长率均稍有提高。     

制备工艺对NR性能的影响

采用新鲜天然胶乳分别制备乙酸凝固NR(NR-1)、微生物凝固NR(NR-2)、乙醇胺混合微生物凝固NR(NR-3)和蛋白酶混合自然凝固NR(NR-4),研究制备工艺对NR性能的影响。结果表明:NR-1和NR-2生胶的耐热老化性能和热稳定性好于NR-3和NR-4生胶;NR-4胶料的MH最大,t90最短,NR-3胶料的MH较小,t90最长;NR-4硫化胶的定伸应力和拉伸强度较大,拉断伸长率较小,NR-1硫化胶的定伸应力和拉伸强度较小;NR-4生胶、混炼胶和硫化胶的弹性转矩(S′)和剪切储能模量(G′)最大,损耗因子(tanδ)最小,NR-1生胶、混炼胶和硫化胶的S′和G′最小,tanδ值最大。     

炭黑对NR／TPI并用胶补强性能的影响研究

研究了炭黑种类扣用量对天然橡胶（NR）／反式-1,4-聚异戊二烯（TPI）并用胶的补强效果。结果表明,合适的混炼工艺下,NR／TPI并用胶中炭黑种类选择N330、其用量为45～50份时,并用胶的拉伸强度、撕裂强度、断裂伸长率最佳,回弹性、硬度适中。屈挠和压缩生热性能较好,达到了对NR／TPI并用胶综合力学性能预期的结果。     

Effect of Phenol-CNSL Formaldehyde on the Thermal Aging of Elastomers-I

Cashew nut shell liquid (CNSL) is a cheap agro-by-product and renewable resource that consists mainly of substituted phenols. A CNSL-based resin was used in this study to modify the properties of the elastomers Isobutylene-Isoprene Rubber (IIR) and Natural Rubber (NR). The resin was a copolymer obtained by condensing a mixture of phenol and CNSL with hexamethylenetetramine. The effect of the resin on the aging properties of elastomers was studied by following changes in tensile strength, elongation at break, modulus, and tear strength. Comparison of the properties of the aged material containing resin with those of specimens not containing any modifiers shows improved aging characteristics with respect to tensile strength, modulus, and tear strength for IIR.     

Compatibilization Effects of PE-g-MA on Mechanical,Thermal and Swelling Properties of High Density Polyethylene/Natural Rubber/Thermoplastic Tapioca Starch Blends

Effect of polyethylene grafted maleic anhydride (PE-g-MA) on mechanical, thermal and swelling characteristic of high density polyethylene (HDPE)/natural rubber (NR)/thermoplastic tapioca starch (TPS) blends were studied. The measurements from differential scanning calorimetric (DSC), dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA), proved the effectiveness of PE-g-MA as compatibilizer in improving the miscibility between HDPE/NR – TPS blends. A decrement in crystallinity index was found after adding PE-g-MA. It is due to restriction in mobility of the HDPE chains. In the presence of PE-g-MA, the blends have better thermal stability. On top of that, the storage modulus which is reflected to the blend stiffness also increased as indicated the improvement in HDPE/NR – TPS interaction.     

Strain effect on recovery behaviors from circular deformation of natural rubber vulcanizate

The recovery behaviors of vulcanized natural rubber from circular deformation were studied by varying sample length to investigate the influence of the degree of applied strain to the sample. The stress and strain varied uniformly across the thickness of the sample, and the degree of applied stress and strain to the sample decreased with increasing the sample length. The linear sample was made into a circular form and thermally aged in a convection oven. The recovery was measured after removing from the circular deformation. The recovery increased by decreasing the sample length. The difference in recoveries of the samples with different lengths reduced at high temperature. The short sample had higher heat‐resisting property for recovery than the long sample. The experimental results were explained by the rearrangement and stabilization of the deformed rubber chains as well as the crosslink density change. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

天然橡胶防腐衬里自然硫化胶料的研制

简要介绍天然橡胶防腐衬里自然硫化胶料的基本配方、衬里的施工工艺及胶粘剂的情况。     

蓖麻油酸改性炭黑对NR性能的影响

采用蓖麻油酸对炭黑进行改性,并研究改性炭黑对NR性能的影响。结果表明,与普通炭黑相比,改性炭黑与橡胶之间的相互作用减弱,导致炭黑结合橡胶质量分数减小;改性炭黑与橡胶之间柔性接点的数量增大,硫化胶的拉伸强度增大;同时改性炭黑间的自聚作用减弱,其在NR中的分散程度提高。