共查询到19条相似文献,搜索用时 140 毫秒
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采用水合肼/双氧水/硫脲体系对天然胶乳进行氢化改性制备氢化天然橡胶(HNR),研究HNR/氢氧化镁[Mg(OH)_2]/环氧化天然橡胶(ENR)复合材料的微观结构和性能。结果表明:制备HNR的最佳氢化条件为水合肼/NR的C=C键物质的量比5.5/1,双氧水/水合肼物质的量比1.85/1,硫酸铜浓度3.5 mmol·kg~(-1),表面活性剂浓度20g·kg~(-1);HNR/Mg(OH)_2/ENR复合材料具有良好的界面相容性;HNR/Mg(OH)_2/ENR并用比为10/5/5的复合材料极限氧指数达到20.7%,阻燃性能良好。 相似文献
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环氧化天然橡胶的研究与应用 总被引:5,自引:0,他引:5
环氧化天然橡胶(ENR)是由NR化学改性而成,笔者阐述了环氧化天然橡胶制备原理和方法、环氧化天然橡胶性能及应用研究、环氧化天然橡胶共混改性研究,其中包括ENR与PVC共混体系的研究、ENR其它共混体系的研究和ENR改性的研究. 相似文献
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环氧化天然橡胶的硫化特性 总被引:1,自引:0,他引:1
用过醋酸法制得的系列环氧化天然橡胶(简称ENR。用硫化仪研究其硫化特性,焦烧性能,助剂影响。通过硫化主硫化期(稳态期)测定ENR有促进剂的硫黄硫化反应动力学级数,表观反应速度常数及表观活化能。 相似文献
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环氧化天然橡胶(ENR)是通过用过酸对天然胶乳进行部分环氧化反应而制成的。环氧化作用使天然橡胶具有较高的气密性、较低的油溶胀性和较高的湿牵引力。近来,使用加速硫黄硫化体系对这些性能的改进及其他特性如焦烧、老化、网状结构等都进行了研究。因为环氧基和不饱和键是ENR中的反应活性部位,所以它们容易进行交联和化学改性。当不饱和键可与硫黄过氧化物和其他交联剂发生交联时,环氧化物就成为与多官能化合物(如二元酸、多元胺等)发生交联的可能部位。 相似文献
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《Polymer》2014,55(26):6803-6810
The interfacial interaction of composites dominates the properties of polymeric/inorganic nanocomposites. Herein, epoxy and hydroxyl groups are introduced into the natural rubber (NR) molecular chains to anchor oxygenous functional groups on the surface of graphene oxide (GO) sheets and therefore enhance the interfacial interaction between GO and rubber. From the morphological observation and interaction analysis, it is found that epoxidized natural rubber (ENR) latex particles are assembled onto the surfaces of GO sheets by employing hydrogen bonding interaction as driving force. This self-assembly depresses restacking and agglomeration of GO sheets and leads to homogenous dispersion of GO within ENR matrix. The formation of hydrogen bonding interface between ENR and GO demonstrates a significant reinforcement for the ENR host. Compared with those of pure ENR, the composite with 0.7 wt% GO loading receives 87% increase in tensile strength and 8.7 fold increase in modulus at 200% elongation after static in-situ vulcanization. 相似文献
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Natural rubber (NR) was blended with chlorosulfonated polyethylene (CSM) with various formulation and blend ratios (NR/CSM: 80/20 –20/80, wt/wt). Rubber blends were prepared by using a two‐roll mill and vulcanized in a compression mold to obtain the 2 mm‐thick sheets. Tensile properties, tear resistance, thermal aging resistance, ozone resistance, and oil resistance were determined according to ASTM. Compatible NR/CSM blends are derived from certain blends containing 20–30% CSM without adding any compatibilizing agent. Tensile and tear strength of NR‐rich blends for certain formulations show positive deviation from the rule of mixture. Thermal aging resistance depends on formulation and blend ratio, while ozone and oil resistance of the blends increase with CSM content. Homogenizing agents used were Stuktol®60NS and Epoxyprene®25. Stuktol®60NS tends to decrease the mechanical properties of the blends and shows no significant effect on blend morphology. Addition of 5–10 phr of epoxidized natural rubber (ENR, Epoxyprene® 25) increases tensile strength, thermal aging resistance, and ozone resistance of the blends. It is found that ENR acts as a compatibilizer of the NR/CSM blends by decreasing both CSM particle size diameter and α transition temperature of CSM. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 127–140, 2006 相似文献
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利用热重-微商热重( TG-DTG-DSC)研究了在氮气、空气氛围中ENR硫化胶的热降解动力学,根据不同升温速率下得到的热重数据,通过Ozawa-Flynn-Wall模型求取热降解过程的活化能E、指前因子A等参数,得到ENR硫化胶在不同气氛下降解反应过程中动力学参数方面的差异。 ENR在氮气气氛中降解时为一步反应,在空气中为复杂多步反应。另外,空气气氛中的活化能E和指前因子A均大于氮气中。 相似文献
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Thermoplastic natural rubber based on polyamide‐12 (PA‐12) blend was prepared by melt blending technique. Influence of blending techniques (i.e., simple blend and dynamic vulcanization) and types of natural rubber (i.e., unmodified natural rubber (NR) and epoxidized natural rubber (ENR)) on properties of the blends were investigated. It was found that the simple blends with the proportion of rubber ~ 60 wt % exhibited cocontinuous phase structure while the dynamically cured blends showed dispersed morphology. Furthermore, the blend of ENR exhibited superior mechanical properties, stress relaxation behavior, and fine grain morphology than those of the blend of the unmodified NR. This is attributed to chemical interaction between oxirane groups in ENR molecules and polar functional groups in PA‐12 molecules which caused higher interfacial adhesion. It was also found that the dynamic vulcanization caused enhancement of strength and hardness properties. Temperature scanning stress relaxation measurement revealed improvement of stress relaxation properties and thermal resistance of the dynamically cured ENR/PA‐12 blend. This is attributed to synergistic effects of dynamic vulcanization of ENR and chemical reaction of the ENR and PA‐12 molecules. Furthermore, the dynamically cured ENR/PA‐12 blend exhibited smaller rubber particles dispersed in the PA‐12 matrix. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
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《国际聚合物材料杂志》2012,61(5):351-364
In this work, natural rubber (NR) and regenerated cellulose (cel II) latexes were co-coagulated and to the mixture epoxidized natural rubber (ENR) was added on a two-roll mill. The cellulose content was fixed at 20 phr while ENR content varied from 0 to 75 phr. The influence of ENR was studied through the cure characteristics, aging and dynamic-mechanical properties. The aging provides nanocomposites with better solvent resistance and increased tensile strength at ENR content of 25 phr. The results suggest that a new type of light-colored nanocomposites were obtained, which presented high mechanical performance and resistance to solvents. 相似文献
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《国际聚合物材料杂志》2012,61(5):330-341
Epoxidized natural rubber (ENR) samples of various epoxidation degrees were synthesized from natural rubber (NR) latex, and 25 mole% epoxide of ENR was used to prepare ENR room temperature-curable films for coating applications. The films were prepared from rubber solutions. Trimethylolpropane tris(2-mercaptoacetate) (TMP-SH) was used as a curing agent. The effect of the thiol additive on the tensile and thermal properties of epoxidized natural rubber (ENR) was investigated. For the sake of comparison, NR and TMP-SH-containing formulations were also prepared. It was observed that the addition of TMP-SH improved the tensile, thermal and swelling properties of ENR, indicating the formation of crosslinks. On the other hand, the addition of TMP-SH didn't improve the properties of NR, indicating the absence of reaction with TMP-SH. On the basis of data on the properties of the ENR films of this work it is demonstrated that these are appropriate for coating applications. 相似文献
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The curing properties and adhesive strengths of the epoxidized natural rubber (ENR, 25 mole percent epoxidation) modified epoxy systems are studied with differential thermal calorimetry (DSC), scanning electron microscopy (SEM), and lap shear strength (LSS) measurement. The results of DSC analyses indicate that the curing exotherm, the curing rate, the reaction order, and the glass transition temperature of the epoxy system are affected by the presence of reactive ENR. From SEM micrographs, it is obtained that a second spherical rubber phase is formed during cure and the particle size of the rubber phase is increased by increasing the curing temperature and the ENR content. The changes of the volume fraction of the rubber phase and the Tg of the cured systems indicate that the mutual dissolution between epoxy resin and ENR happens and which changes with the curing temperature and the ENR content. The LSS of adhesive joints prepared with the ENR modified adhesives are all lower than those of the unmodified epoxy system, and decrease with increasing the amount of ENR added because of the limited compatibility of the ENR with the epoxy matrix. 相似文献
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Si-Dong Li Ying Chen Jiang Zhou Pei-Sen Li Cheng-Shen Zhu Mu-Liang Lin 《应用聚合物科学杂志》1998,67(13):2207-2211
The thermal degradation and thermooxidative degradation of epoxidized natural rubber (ENR) were studied by thermogravimetry (TG). In the thermal degradation of ENR, the initial temperature of weight loss T0 = 1.20B + 348, the temperature of maximum weight loss rate Tp = 1.07B + 392, and the final temperature of weight loss Tf = 0.77B + 445. The Cp, which corresponds to the degradation rate at temperature Tp, increases along with the heating rate B and its mean value is 43%, but Cf, which corresponds to the degradation rate at temperature Tf, is not affected by the heating rate, and its average value is close to 100%. As in the thermooxidative degradation, T0 = 1.84B + 246, Tp = 0.30B + 378, and Tf = 2.27B + 584. The value of Cp increases along with the heating rate B and its mean value is 36%, but Cf is not affected by the heating rate and the average value approximately equals 100%. The thermal degradation in nitrogen could be a one-step reaction, whereas the thermooxidative degradation has a multiple-step reaction. The reactive environment has a great effect on the thermal degradation of ENR and the difference of the mechanisms of the two reaction systems is obvious. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2207–2211, 1998 相似文献