环氧化天然橡胶共交联改性EPDM/NR共混物的性能

将三元乙丙橡胶(EPDM)与环氧化天然橡胶(ENR)共交联改性后,再与天然橡胶(NR)共混,考察了ENR共交联改性EPDM/NR共混胶的硫化特性、硫化胶的物理机械性能、溶胀指数和耐热空气老化性能,并对该硫化胶进行了差示扫描量热分析。结果表明,EPDM经过ENR共交联改性后与NR共混,ENR共交联改性EPDM/NR共混胶的交联程度明显提高,各相达到了同步交联,硫化胶的综合性能得到了显著改善。     

EPDM/NR共混橡胶的性能研究

采用硫黄硫化体系和过氧化物(硫化剂DCP)硫化体系对EPDM/NR并用胶实施复合交联,考察了不同共混比EPDM/NR共混胶的硫化特性、硫化胶的物理机械性能、耐水性及耐溶剂性能。结果表明:复合交联后,胶料的硫化特性、物理机械性能均有所提高;EPDM母炼胶中DCP的用量要高于NR;胶料共混比为80/20(EPDM/NR),其耐水性和耐溶剂性能达到最佳。     

改性NR对PVC增韧研究

研究了改性天然橡胶(NR)的性质对聚氯乙烯(PVC)硬质材料的增韧作用。发现改性NR的主链结构、支链的极性、NR含量等是影响改性NR/PVC共混材料的冲击强度的主要因素。交联型改性NR对PVC有显著的增韧效果,其共混材料的冲击强度高达60kJ/m~2,比纯PVC材料高15倍以上。扫描电子显微镜照片显示交联型改性NR/PVC共混材料的冲击断面布满均匀细密的“须根”,无裂缝,无NR粒子剥离现象。透射电子显微镜分析显示,交联型改性NR/PVC的相界面有模糊的过渡层,说明二者部分相容。     

反式聚辛烯橡胶改性天然橡胶/顺丁橡胶共混胶的性能

研究了反式聚辛烯橡胶(TOR)改性天然橡胶(NR)/顺丁橡胶(BR)(二者质量比80/20)共混胶的性能.结果表明,采用5～15份(质量,下同)TOR改性NR/BR混炼胶的门尼黏度逐渐降低、Payne效应基本不变,共混胶的焦烧时间和工艺正硫化时间延长、硫化速率减慢.相比NR/BR硫化胶,NR/BR/TOR硫化胶的拉伸强...     

微生物脱硫胶粉/天然橡胶共混胶的性能

用微生物提取物脱硫改性胶粉(RP),考察了脱硫胶粉(DRP)用量对其与天然橡胶(NR)共混胶的硫化性能、动态力学性能以及物理机械性能的影响,并与RP/NR共混胶进行了对比.结果表明,DRP的加入提高了其与NR的交联程度;DRP/NR混炼胶的Payne效应较RP/NR混炼胶小;随着DRP用量的增加,DRP/NR硫化胶的储能模量降低,损耗因子增大;DRP/NR硫化胶的物理机械性能随着DRP用量的增加而下降,但优于RP/NR硫化胶;DRP在NR中的分散性较RP均匀,与NR的界面结合更强.     

MAH改性PE/PA6共混体系的热致形状记忆功能

采用马来酸酐(MAH)改性聚乙烯(PE)与尼龙6(PA6)接枝共混方法制备具有微晶物理交联结构的形状记忆体系。在不同条件下,对不同组分含量试样的形状回复率进行测试,研究回复温度、拉伸率、形变固定时间、回复次数等因素对该体系形状记忆性能的影响。结果表明,这些因素对体系微晶物理交联结构稳定的影响是导致形状记忆性能变化的根本原因。     

废聚乙烯薄膜氯化产物在橡胶中的应用

将废聚乙烯农地膜氯化产物(CWPE)与几种二烯类橡胶并用,研究了硫化条件及混合配比对产物性能的影响,结果表明,硫载体硫化体系和过氧化物硫化体系都可以使CWPE和混合体系硫化。CWPE分别占20％～40％、60％和75％时,CWPE与NBR、SBR、NR共混物的拉伸强度、伸长率和永久形变达到最佳值。     

Si747原位改性单分散白炭黑补强天然橡胶的性能研究

采用Si747在液相体系中对自制单分散白炭黑表面进行改性,利用乳液共混技术制备了天然橡胶(NR)复合材料,并通过橡胶加工分析、动态力学分析、透射电镜等测试手段对复合材料的结构与性能进行表征。结果表明,与未改性白炭黑相比,改性单分散白炭黑所得胶料的焦烧时间和工艺正硫化时间均缩短,促进了橡胶的硫化;改性单分散白炭黑/NR硫化胶的拉伸、撕裂强度增大,回弹性和耐磨性增加,压缩生热降低;改性前后,大粒径白炭黑复合材料Payne效应均较低;改性小粒径白炭黑抗湿滑性不如改性大粒径白炭黑/NR硫化胶,但滚动阻力表现更优。     

改性胶粉/天然橡胶共混体系结构与性能的研究

采用自制的聚腰果酚对胶粉(RP)进行脱硫反应制得接枝改性胶粉(MRP),将其与天然橡胶(NR)共混,并研究MRP/NR共混体系的结构与性能。结果表明:MRP/NR共混体系的物理性能优于RP/NR共混体系,耐老化性能优于NR和RP/NR共混体系;添加六亚甲基四胺(HMTA)可以进一步提高MRP/NR共混体系的物理性能,当MRP用量为50份、HMTA用量为0.5份时,MRP/NR共混体系的物理性能与NR硫化胶相当。     

特种共混型热塑性弹性体——Ⅱ.CPE及CSM与PA共混体系的组成对性能的影响

以CPE、CSM 及PA为原料,采用动态硫化法制备了具有特殊性能的共混型热塑性弹性体,考察了各种因素对共混物性能的影响,比较了 CPE/PA 和 CSM/PA 的综合性能。结果表明,橡胶相的交联程度对共混物的综合性能有较大影响;在 CPE/PA 共混体系中,DCP 交联体系较促进剂 NA-22 为优;助交联剂 TAIC 在本体系中起改性作用;白炭黑在共混体系中无明显补强效果,但经表面处理后,可提高橡胶相的交联程度;从共混物的返炼特性判断,当 CPE/PA(质量份)为 90/10—80/20时发生相转变;CPE/PA 的综合性能较 CSM/PA 为优。     

氧化石墨烯/天然橡胶复合材料的制备与性能

采用己内酰胺（CPL）改性氧化石墨烯（GO）（CPL-GO）,与天然橡胶（NR）复合后通过熔融共混法制备了CPL-GO/NR复合材料。考察了CPL-GO用量对CPL-GO/NR复合材料物理机械性能、界面相互作用和气体阻隔性能的影响。结果表明,CPL改性GO后,X射线衍射层间距增加,片层堆砌更为松散,CPL-GO与水接触角增至91.2°。当CPL-GO的质量分数为2.0%时,CPL-GO/NR复合材料的拉伸强度为26.1 MPa,较纯NR提高了50.9%。随着CPL-GO用量的增加,复合材料的储能模量增加,损耗因子的峰值减小,表明GO经CPL表面改性后与NR复合,增强了两相界面间的相互作用,从而提高了复合材料抵抗变形的能力。在40 ℃下,当CPL-GO的质量分数为3.0%时,CPL-GO/NR复合材料的气体渗透系数较纯NR下降了57.1%。     

Reclaiming of rubber by a renewable resource material (RRM). III. evaluation of properties of NR reclaim

Sulfur‐cured filled natural rubber (NR) is successfully reclaimed by using a renewable resource material (RRM) and diallyl disulfide (DADS), which is the major constituent of RRM. Reclaiming of NR vulcanizate was carried out at 60°C for 35 min in an open two‐roll mixing mill. Evaluation of the properties of NR reclaim was carried out by mixing it with virgin rubber in various proportions. The cure characteristics and mechanical properties of the virgin NR/ reclaim NR blend were studied. With increase in the proportion of reclaim rubber (RR) in virgin NR/ reclaim NR blend scorch time and optimum cure time decrease. To increase scorch time N‐cyclohexylthiophthalimide as prevulcanization inhibitor (PVI) was added in NR/RR (50/50) blend. It was found that use of 40% NR reclaim with virgin rubber resulted 83% retention of tensile strength of that of the virgin NR vulcanizate. Effect of carbon black loading was studied in NR/RR (50/50) blends. Tensile properties and swelling value of different NR/RR blends were evaluated before and after aging. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1493–1502, 2000     

Effect of zinc oxide nanoparticles as cure activator on the properties of natural rubber and nitrile rubber

Zinc oxide (ZnO) nanoparticles were synthesized by homogeneous precipitation and calcination method and were then characterized by transmission electron microscopy and X‐ray diffraction analysis. Synthesized ZnO was found to have no impurity and had a dimension ranging from 30–70 nm with an average of 50 nm. The effect of these ZnO nanoparticles as cure activator was studied for the first time in natural rubber (NR) and nitrile rubber (NBR) and compared with conventional rubber grade ZnO with special reference to mechanical and dynamic mechanical properties. From the rheograph, the maximum torque value was found to increase for both NR and NBR compounds containing ZnO nanoparticles. ZnO nanoparticles were found to be more uniformly dispersed in the rubber matrix in comparison with the conventional rubber grade ZnO as evident from scanning electron microscopy/X‐ray dot mapping analysis. The tensile strength was observed to improve by 80% for NR when ZnO nanoparticles were used as cure activator instead of conventional rubber grade ZnO. An improvement of 70% was observed in the case of NBR. The glass transition temperature (T_g) showed a positive shift by 6°C for both NR and NBR nanocomposites, which indicated an increase in crosslinking density. The swelling ratio was found to decrease in the case of both NR and NBR, and volume fraction of rubber in swollen gel was observed to increase, which supported the improvement in mechanical and dynamic mechanical properties. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

废旧轮胎热解行为的TG/DTA研究

运用热重/差热联用仪（TG/DTA）研究了4种废旧轮胎样品及3种橡胶原料（天然橡胶、丁苯橡胶、顺丁橡胶）的热解行为,通过TG/DTA数据计算了各个降解阶段的热解动力学参数（表观活化能和指前因子）,并确定了轮胎中的橡胶类型（天然胶和合成胶）,得到其基本组成（有机助剂、橡胶、炭黑和无机助剂）的含量,为进行废旧轮胎的转化利用提供基础数据。结果表明:橡胶原料、轮胎样品的热解过程均可划分为两个一级反应阶段,其中轮胎样品的第1段热解活化能比第2段的小,随着反应温度的升高及转化深度的增大,热解对温度的依赖程度增大;废轮胎样品中可热解部分为64％～66％,炭黑为30％～33％,灰分为3％～6％;升温速率可明显地改变轮胎样品的热解历程,但对热解产物的收率影响甚微;天然橡胶的热解失重和合成橡胶的解聚使废旧轮胎的热解表现为一放热过程。     

POE对NR性能的影响研究

研究了不同牌号POE对天然橡胶(NR)性能的影响,结果表明POE 8200与NR有较好的相容性,而POE 8003和POE 8480不容易分散在NR中;且POE 8200能显著提高胶料的拉伸强度及扯断伸长率,并能改善胶料的耐热老化性能,同时NR的拉伸疲劳寿命随着POE 8200用量的增大呈现出先增大后下降的趋势,其用量为1份时疲劳寿命最好。     

Swelling behavior of NR/EPDM rubber blends under compression strain

The effect of different blend compositions of natural rubber (NR)/ethylene–propylene diene monomer rubber (EPDM) on the swelling behavior of that blend in motor oil under compression strain was investigated. The compression recovery of all blend ratios investigated had positive values at low applied compression values (3%). However, at high compression values (18 and 35%), the compression recovery had negative values. The lower weight uptake of motor oil was shown by the EPDM vulcanizate, whereas the 25/75 NR/EPDM blend showed the highest compression recovery. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3052–3057, 2001     

Study on the milling behavior of chloroprene rubber blends with ethylene–propylene–diene monomer rubber,polybutadiene rubber,and natural rubber

The viscoelastic properties of the blends of chloroprene rubber (CR) with ethylene–propylene–diene monomer rubber (EPDM), polybutadiene rubber (BR), and natural rubber (NR) at different temperature were studied using rubber processing analyzer (RPA). Mooney viscosities of compounds were measured and tight milling and sheeting appearance were observed on a two‐roll mill. The results showed that Mooney viscosities and the elastic modulus of the blends decreased with the increase of the temperature from 60 to 100°C. And the decreasing trends of pure CR, pure NR, and CR/NR blend compounds were more prominent than that of pure EPDM, pure BR, CR/EPDM, and CR/BR blend compounds. For CR/EPDM blend compounds, the decreasing trend became slower with the increase of EPDM ratio in the blend. Compared with pure CR, pure NR and CR/NR blend compounds, pure EPDM, pure BR compounds, and the blend compounds of CR/EPDM and CR/BR showed less sensibility to temperature and they were less sticky to the metal surface of rolls and could be kept in elastic state at higher temperature, easy to be milled up and sheeted. At the same blend ratio and temperature, the property of tight milling of the blends decreased in the sequence of CR/EPDM, CR/BR, and CR/NR. With the increase of EPDM, BR, or NR ratio in CR blends, its property of tight milling was improved. POLYM. COMPOS., 28:667–673, 2007. © 2007 Society of Plastics Engineers     

Toughening of polylactide with natural rubber grafted with poly(butyl acrylate)

Natural rubber grafted with poly(butyl acrylate) (NR‐g‐PBA) in an attempt to toughen polylactide (PLA) was prepared by grafting butyl acrylate onto natural rubber (NR) through emulsion polymerization. The purified NR‐g‐PBA was confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance spectroscopy. NR‐g‐PBA/PLA blend and NR/PLA blend were prepared with a Haake internal melt mixer. The morphology and mechanical properties of the blends were investigated as a function of rubber content. Observations by scanning electron microscopy showed that the spherical‐particle‐dispersed phase appearing in the NR/PLA blend was not found in the NR‐g‐PBA/PLA blend, which showed that NR grafted with PBA is compatible with PLA, and accounted for the efficient toughening effect on PLA. The elongation at break and the impact strength were significantly improved with an increase in NR‐g‐PBA content. The thermal stability of PLA decreased when blended with NR but was retained with NR‐g‐PBA. Copyright © 2011 Society of Chemical Industry     

Silica nanoparticles reinforced natural rubber latex composites: The effects of silica dimension and polydispersity on performance

The nano-size autonomous monodisperse silica (AS) particles were prepared by hydrolysis and condensation of tetraethoxysilane using l -lysine as catalyst. The silica/natural rubber (NR) masterbatches were then produced via latex compounding, in which NR latex was mixed with the above AS dispersion. The commercial precipitated silica (PS) was introduced as a control. The effects of both AS and PS particles on the interfacial and mechanical properties of composites were systematically examined. It was found that the AS formed bead-like morphology wherein the clear particle edges can be distinguished in rubber matrix. Compared with PS/NR, the AS/NR composites were proved to possess more bound rubber and weaker filler–filler interaction resulting in higher tensile strength, abrasive resistance, and resilience. Meanwhile, the efficiency of premodified AS and PS surfaces using bis-(3-triethoxysilylpropyl) tetrasulfide on reinforcing the properties of silica/NR composites was studied. The results presented that the overall properties of modified silica/NR vulcanizates were improved significantly. In special, the values of heating building-up and compression set showed an evident decline which was of great significance for tire tread or other rubber products. For the dynamic properties, the magic angle spinning/NR composites had lower rolling resistance. In short, AS may be applied as an ideal substitution of PS in rubber. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47449.     

Synergistic reinforcement of nanoclay and carbon black in natural rubber

The synergistic reinforcement of nanoclay (NC) and carbon black (CB) in natural rubber (NR) has not been much studied. Therefore, the reinforcement mechanism was probed using synchrotron wide‐angle X‐ray diffraction and transmission electron microscopy (TEM) observation and analyzed in terms of tube model theory. A synergistic effect in reinforcement between NC and CB was proved by the marked enhancement in tensile strength from 11.4 MPa for neat NR to 28.2 MPa for NR nanocomposite with 5 wt% NC and 20 wt% CB. From a study of crystallization under deformation it was found that crystallization plays a less important role in the reinforcement of NR/NC/CB. Analysis using tube model theory provided more evidence for the synergistic effect. NR containing a combination of NC and CB exhibited an increase of topological tube‐like constraints in comparison with NR/CB. That is to say, in NR/NC/CB nanocomposites, a CB–NC local filler network, as indicated by TEM images, induced a more entangled structure in which mobility of rubber chains was hindered for lateral fluctuations by the presence of neighboring chains. The synergistic reinforcement of NC and CB in NR/NC/CB nanocomposites can be reasonably understood as due to the formation CB–NC local filler networks. Copyright © 2010 Society of Chemical Industry