新型防老剂RT-1对天然橡胶性能的影响

研究新型防老剂RT-1对天然橡胶(NR)性能的影响。结果表明:加入防老剂RT-1,NR胶料的ML增大,MH减小,t90和ts1延长,老化后NR硫化胶的拉伸性能较好,热氧化活化能增大;防老剂RT-1对NR硫化胶热氧老化的防护效果优于防老剂BHT和4010NA。     

防老剂2,4-二叔丁基-6-环己亚胺苯酚的制备及在天然橡胶中的应用

采用环己胺改性3,5-二叔丁基水杨醛的方法,在其酚羟基邻位上引入了供电子基团碳氮双键,合成了新型防老剂2,4-二叔丁基-6-环己亚胺苯酚,利用红外光谱、紫外-可见光光谱及核磁共振仪对合成产物进行了表征,并对比了自制防老剂与3,5-二叔丁基水杨醛和防老剂2,2'-亚甲基双-(4-甲基-6-叔丁基苯酚)(防老剂2246)的耐老化性能。结果表明,防老剂2,4-二叔丁基-6-环己亚胺苯酚能够延长天然橡胶混炼胶的焦烧时间,改善其硫化胶的拉伸强度、扯断伸长率及热稳定性;随着老化时间的延长,2,4-二叔丁基-6-环己亚胺苯酚的耐老化效果略优于防老剂2246,明显优于反应物3,5-二叔丁基水杨醛。     

氧化石墨烯接枝防老剂的合成及在天然橡胶中的应用

采用防老剂4010 NA中间体(RT)与氯化亚砜处理的氧化石墨烯(GO)反应,制得天然橡胶(NR)/接枝防老剂GO-RT复合材料。结果表明,防老剂GO-RT在NR中的接枝率为10.54%。NR/GO-RT复合材料的力学性能保留率与抗抽提能力均优于采用防老剂4010 NA制备的复合材料。GO-RT在NR中具有优良的抗热氧老化性能是由于其提高了NR的降解活化能,并降低了NR老化过程中的自由基浓度。     

新型防老剂4030合成与应用

1 概述 防老剂4030,结构式： 化学名称,N,N′-双（1,4-二甲基戊基）-对苯二胺,暗红色液体,沸点237℃,相对密度0．894-0．906,闪点203℃,溶于二硫化碳、氯仿、苯、石油醚、乙醇,不溶于水,毒性比较小,小白鼠的经口LD50为750mg／kg体重。对皮肤有刺激性,有时会引起皮肤过敏反应。是一种高效的抗臭氧型防护剂,适用于天然胶和合成弹性体胶料。尤其适用于无防护蜡的静态使用的胶料。     

天然橡胶的热氧老化研究

为了改善天然橡胶的热氧老化性能，试验了防老剂D提纯品和工业品对天然橡胶热氧老化性能的影响，调试了其热氧化诱导期、热失重、热老化的性能变化。结果表明：含杂少纯度高的防老剂D使天然橡胶的抗热氧老化得到改善。     

新工艺环保型防老剂264对天然橡胶热氧老化性能的影响

对比普通防老剂264,研究新工艺环保型防老剂264（简称新型防老剂264）对天然橡胶（NR）胶料的硫化特性、热氧老化性能及其耐水抽出性能的影响。结果表明,与普通防老剂相比,新型防老剂264对NR胶料的硫化特性影响不明显,其耐水抽出性能及胶料的耐热氧老化性能较好,更适合在潮湿的环境下使用。新型防老剂264在NR胶料中的用量以1～2份为宜。     

耐热氧/耐臭氧型防老剂防护性能和迁移污染性的研究

研究耐热氧/耐臭氧型防老剂YC-B30(二苯胺类)、YC-B60(二苯胺类)、YC-D30(三嗪类)和YC-D60(对苯二胺类)对胶料加工性能、耐热氧老化性能和耐臭氧老化性能的影响,并探究其迁移污染性。结果表明,与普通防老剂4020/RD并用防护体系硫化胶相比,耐热氧/耐臭氧型防老剂防护体系硫化胶的耐热氧老化和耐臭氧老化性能较好,其中高效耐臭氧型防老剂YC-D60硫化胶的耐臭氧老化性能最佳,普通防老剂4020/耐热氧防老剂YC-B60/耐臭氧防老剂YC-D60并用的防护体系实际使用价值更高。     

稀土型受阻酚类防老剂在天然橡胶中的应用

以受阻酚为有机配体制备稀土(镧、铈、镨、钕、钐和铕)型受阻酚类防老剂,采用红外光谱、热重分析法对合成的稀土配合物进行初步表征,研究稀土型受阻酚类防老剂对天然橡胶(NR)硫化特性、物理性能和耐老化性能的影响。结果表明:添加各稀土型受阻酚类防老剂的NR胶料具有相似的硫化特性,NR硫化胶的物理性能和耐老化性能获得改善,其中稀土镧型受阻酚类防老剂效果最佳。     

高二聚体含量防老剂RD在胶料中的应用

对高二聚体含量防老剂RD胶料性能与普通防老剂RD胶料性能进行对比。结果表明:高二聚体含量防老剂RD有效含量和二聚体含量比普通防老剂RD更高,分子结构基本一致;高二聚体含量防老剂RD胶料的耐热氧老化性能优于普通防老剂RD胶料;高二聚体含量防老剂RD用量比普通防老剂RD用量减小1/3时胶料的耐热氧老化性能相当。     

新型防老剂N3100单组分应用性能研究

对新型对苯二胺类防老剂N3100的3个单组分与传统混合型防老剂3100进行应用对比试验。结果表明,防老剂N3100各单组分对胶料的热氧老化防护效果优于防老剂N3100,其他防护效果与防老剂N3100相当或略好;防老剂N3100各单组分胶料性能存在差异,其中N-苯基-N′-甲苯基对苯二胺胶料综合性能较好。     

防老剂N-（4-苯胺基苯基）-甲基丙烯酰胺的制备及其在天然橡胶中的应用

用甲基丙烯酰氯和对氨基二苯胺制备了反应性非迁移防老剂N-(4-苯胺基苯基)-甲基丙烯酰胺(NAPM),用红外光谱对其进行了表征,研究了其用于天然橡胶(NR)时硫化胶的物理机械性能和耐老化性能,并与防老刺4010 NA和4020进行了比较.扫描电镜和透射电镜分析结果表明,添加NAPM的NR硫化胶表面呈现一种网状结构,提高了NAPM在NR中的稳定性.NR硫化胶在70℃老化48 h后,NAPM的老化系数(K)与4010 NA和4020相差甚微;老化时间延长24 h后其K值明显高于4010 NA和4020,K(4020)/K(4010 NA)仅增加了3.09%,而K(NAPM)/K(4010 NA)却增加了14.21%,表明添加NAPM的NR硫化胶的耐老化性能明显优于添加4010 NA和4020的NR硫化胶.     

Preparation of lignin-based filling antioxidant and its application in styrene-butadiene rubber

A novel filling antioxidant (Lig-g-RT) to improve the mechanical properties and antiaging performance of styrene-butadiene rubber (SBR) composites was prepared by grafting antioxidant intermediate p-aminodiphenylamine (RT) on the surface of lignin via the linkage of silane coupling agent. Fourier transform infrared (FTIR) and thermogravimetric analysis (TGA) measurements confirmed that RT was successfully grafted on the surface of lignin to produce the functionalized Lig-g-RT which shows a better thermal stability than lignin. Compared with SBR/lignin composite, the SBR/Lig-g-RT composite using latex co-precipitation method exhibits a much better filler dispersion, which contributes to the maintain of the physical mechanical properties of SBR vulcanizates. Moreover, the SBR/Lig-g-RT vulcanizate exhibits less chemical crosslink concentration and higher entanglement density than SBR/lignin vulcanizate according to the Mooney–Rivlin model analysis. In addition, the stabilizing effect of lignin/Lig-g-RT on the carbon-black filled SBR vulcanizates is comparable with that of commercial antioxidant N-1,3-dimethylbutyl-N′-phenyl-p-phenylenediamine (4020), especially the SBR vulcanizate filled with 10 phr Lig-g-RT obtains the optimum thermo-oxidative aging properties. This functionalized Lig-g-RT not only provides an intramolecular synergistic antiaging effect for SBR vulcanizates and an improvement of filler dispersion, but greatly extends the comprehensive utilization of industrial lignin.     

胶粉中二氧化硅的原位生成及其在天然橡胶中的应用

通过溶胶-凝胶法在胶粉中原位生成纳米二氧化硅网络,经傅里叶变换红外光谱和热重分析,结果证实在溶胶-凝胶反应中于胶粉表面过渡层中可原位生成质量分数约3%～5%的类似二氧化硅的网络结构.改性胶粉表现出更好的热稳定性,失重5%的温度比未改性时提高了约30%.将50份(质量)改性胶粉填充到天然橡胶中后,所得天然橡胶/改性胶粉复合材料仍具有较好的物理机械性能和动态力学性能.     

Synthesis and characterization of chlorinated paraffin wax-bound paraphenylenediamine antioxidant and its application in natural rubber

p-Phenylenediamine was chemically attached to low molecular weight chlorinated paraffin wax. The polymer-bound p-phenylenediamine was characterized by vapor-phase osmometry (VPO), proton magnetic resonance spectroscopy (¹H-NMR), infrared spectroscopy (IR), and thermogravimetric analysis (TGA). The efficiency and permanence of the polymer-bound p-phenylenediamine as an antioxidant was compared with a conventional amine-type antioxidant in natural rubber vulcanizates. The vulcanizates showed improved aging resistance in comparison to vulcanizates containing a conventional antioxidant. The presence of liquid polymer-bound p-phenylenediamine also reduces the amount of the plasticizer required for compounding. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2183–2189, 2001     

超支化有机蒙脱土阻燃剂的制备及其在天然橡胶中的应用

采用超支化及有机改性技术成功制备了超支化有机蒙脱土阻燃剂(HFR-OMMT)。通过X射线衍射(XRD)和热失重分析(TGA)手段分析了HFR-OMMT的结构与性能。制备了天然橡胶(NR)/HFR-OMMT复合材料,研究了其阻燃和物理机械性能。结果表明,NR/HFR-OMMT复合材料的力学、耐磨和阻燃性能均得到一定程度的改善。     

马来酸酐接枝天然橡胶的制备及应用研究

以过氧化二异丙苯(DCP)为引发剂,在转矩流变仪中以马来酸酐(MAH)单体对天然橡胶(NR)进行接枝改性。通过傅里叶变换红外光谱对接枝物进行了定性表征;采用化学滴定法测定了反应产物中MAH的接枝率和接枝效率。研究了MAH单体用量、DCP用量、反应温度、转子转速等因素对反应产物接枝率和接枝效率的影响,研究结果表明,以转矩流变仪作为反应器,NR为100份(质量份数,以下同此),MAH和DCP分别为5份、0.75份,温度为130℃,转子转速为50 r/min的条件下反应3min,产物接枝率和接枝效率较高,分别为1.45%和30.63%。将所制备的马来酸酐接枝天然橡胶(NR-g-MAH)应用于尼龙短纤维增强天然橡胶复合材料(NR/SF)体系中,可有效改善尼龙短纤维与NR基体间的界面结合。     

新型天然橡胶吸油材料的制备及性能

以天然橡胶(NR)接枝马来酸酐(NR-g-MAH)和NR接枝甲基丙烯酸甲酯(NR-g-MMA)为NR/甲基丙烯酸十八酯-丙烯酸丁酯-苯乙烯共聚物(SMA-BA-St)吸油材料的增容剂,研究了各组分配比、增容剂的种类及用量对吸油材料吸油能力和力学性能的影响,并采用热重分析及扫描电子显微镜对吸油材料进行了表征。结果表明,以NR-g-MAH为增容剂时,吸油材料的力学性能和吸油率优于以NR-g-MMA为增容剂时的吸油材料;当NR/SMA-BA-St/NR-g-MAH(质量比)为100/10/5时,材料具有较好的力学性能、吸油性能和老化性能;随着增容剂接枝率的增大,吸油材料的力学性能和吸油性能呈上升趋势;吸油材料在CCl4、甲苯、苯、柴油和机油中的饱和吸油率分别为37.48,32.45,29.26,23.06,16.79g/g,保油率可超过85%;对CCl4的二次吸油率可达30g/g;以NR-g-MAH和NR-g-MMA增容吸油材料的热稳定性比SMA-BA-St优异,且在常温下使用很稳定;NR-g-MAH的增容效果优于NR-g-MMA,有效改善了NR与SMA-BA-St的相容性。     

Preparation and characterization of organoclay‐rubber nanocomposites via a new route with skim natural rubber latex

Skim natural rubber latex (SNRL) is a protein rich by‐product obtained during the centrifugal concentration of natural rubber (NR) latex. A new method to recover rubber hydrocarbon and to obtain nanocomposites with organoclay (OC) was investigated. The approach involved treatment of SNRL with alkali and surfactant, leading to creaming of skim latex and removal of clear aqueous phase before addition of OC dispersion. Clay mixed latex was then coagulated to a consolidated mass by formic acid, followed by drying and vulcanization like a conventional rubber vulcanizate. X‐ray diffraction (XRD) studies revealed that NR nanocomposites exhibited a highly intercalated structure up to a loading of 15 phr (parts per hundred rubber) of OC. Transmission electron microscopy studies showed a highly exfoliated and intercalated structure for the NR nanocomposites at loadings of 3–5 phr organically modified montmorillonite (OMMT). The presence of clay resulted in a faster onset of cure and higher rheometric torque. The rubber recovered from skim latex had a high gum strength, and a low amount of OC (5 phr) improved the modulus and tensile strength of NR. The high tensile strength was supported by the tensile fractography from scanning electron microscopy. Thermal ageing at 70°C for 6 days resulted in an improvement in the modulus of the samples; the effect was greater for unfilled NR vulcanizate. The maximum degradation temperature was found to be independent of the presence and concentration of OC. The increased restriction to swelling with the loading of OC suggested a higher level of crosslinking and reinforcement in its presence. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3277–3285, 2006     

Dichlorocarbene modification of natural rubber and its role as a modifier in blends of natural rubber and hydrogenated nitrile rubber

Dichlorocarbene modification of natural rubber (NR) carried out by alkaline hydrolysis of chloroform in presence of cetyl trimethyl ammonium bromide as phase‐transfer catalyst was investigated. Extent of chemical reaction was characterized by estimation of chlorine content and FTIR studies. Rate of dichlorocarbene addition depends on the time and temperature of reaction. Reaction carried out at 60°C for 2 h yielded a material with a chlorine content of 15%. Chemical modification of NR was accompanied by introduction of chlorine through cyclopropyl ring to the main chain of NR as revealed from FTIR studies. As level of chlorination increased, the physical nature of NR changed from a soft flexible state to a hard nontacky form. Blends of NR with hydrogenated nitrile rubber (HNBR) containing three to seven parts of dichlorocarbene‐modified NR (DCNR) of chlorine content 15% could be prepared by conventional mill mixing. Incorporation of DCNR into blends of NR and HNBR promoted polar interaction between the chlorine segments and acrylonitrile segments of the blend as shown from the shift in characteristic IR absorption peaks and shift in T_g from DSC studies. As a consequence, DCNR acted as an interface modifier in blends of NR and HNBR. Blends of NR and HNBR containing DCNR showed a considerable improvement in cure behavior, physical properties, and ageing characteristics in oil, ozone, and high temperature compared to pure blends of NR and HNBR. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4401–4409, 2006     

Surface modification of nanocrystalline cellulose and its application in natural rubber composites

As a biopolymer with high mechanical strength, nanocellulose was generally considered as a green filler for reinforcing polymer. In this study, nanocrystalline cellulose (NCC) isolated from softwood pulp was successfully modified by cetyltrimethyl ammonium bromide (CTMAB), a cationic surfactant, and the modified nanocrystalline cellulose (m-NCC) was used to reinforce natural rubber (NR). In this composite architecture, it was found that when the filler content was 5 or 10 phr, the surface modification of NCC improved the dispersion state of NCC in NR matrix and the interfacial interaction between NR and NCC. Therefore, the NR/m-NCC composites exhibited outstanding mechanical properties, and its tensile strength, elongation at break and tear strength was increased by 132.8, 20, and 66.1%, respectively, compared to pristine NR composites. Besides, the modified NCC could accelerate the vulcanization and improve wet-skid resistance and aging resistance of NR composites. It is envisioned that the modified NCC has the potential to be generalized to manufacturing other polymer matrix composites strengthened with nanocellulose.