硅藻土/天然橡胶复合材料的性能研究

利用环氧化天然胶乳作为硅藻土的界面改性剂,制备了硅藻土/天然橡胶复合材料,通过无转子流变仪、电子万能材料试验机和橡胶动态压缩生热仪,研究了复合材料的硫化特性,物理机械性能和温升特性。结果表明,硅藻土/天然橡胶复合材料的焦烧与正硫化时间随着硅藻土含量的增加,先增后减;最大与最小扭矩随硅藻土含量的增加而增加;硅藻土/天然橡胶复合材料的拉伸与撕裂强度均有提高,当硅藻土含量为4phr时,拉伸强度最高,为28.5MPa;当硅藻土的含量为2phr时,撕裂强度最高,为37.9N/mm;由于硅藻土的加入,材料的内生热显著降低。     

乳液共凝法制备天然橡胶/白炭黑复合材料的性能

以硅酸钠为前驱体,将一定浓度的硅酸钠溶液与天然胶乳共混共凝,使胶乳的凝聚与白炭黑的生成同步发生,从而制得天然橡胶/白炭黑复合材料,并与用传统混炼法制备的复合材料进行了性能对比。结果表明,当白炭黑用量为15份(质量)时,与混炼法相比,采用乳液共凝工艺所制备复合材料的力学性能明显更好,其中拉伸强度和撕裂强度分别提高了62.4%和87.7%;填料粒子在橡胶基质中的分散更为均匀,在60~80℃下的损耗因子也更低。     

射流胶乳混合法天然橡胶复合材料的制备及性能研究

用射流胶乳混合法制备天然橡胶(NR)复合材料,并对复合材料性能进行研究。先用超声空化作用将炭黑团聚体破碎、切割、分散在水中制得炭黑悬浮液,然后在高速射流场中将炭黑微观分散到天然胶乳中制成NR复合材料。结果表明:与传统干法混炼工艺相比,射流胶乳混合工艺可以使炭黑更均匀地分散到NR基体中;射流胶乳混合工艺制备的复合材料硫化时间缩短,硫化程度增大,撕裂强度提高78%,回弹值提高20%,DIN磨耗量减小33%。     

淀粉纳米晶/天然橡胶复合材料的制备和性能(英文)

通过磷酸酸解的方法制备了淀粉纳米晶,与天然胶乳共混沉淀,制备了淀粉纳米晶/天然橡胶纳米复合材料.利用扫描电镜研究了该纳米复合材料的微观结构,表明淀粉纳米晶以50～100 nm的片状颗粒分散在天然橡胶基体中.力学性能结果表明,淀粉纳米晶对天然橡胶具有较好的补强效果.动态力学性能分析表明,添加质量分数为5%的淀粉纳米晶的淀粉纳米晶/天然橡胶纳米复合材料抗湿滑性显著提高,可用作绿色轮胎材料.     

“胶乳共混法”制备天然橡胶／二氧化硅纳米复合材料及其性能

采用γ-甲基丙烯酰氧基丙基三甲氧基硅烷（KH570）改性纳米二氧化硅（SiO2）,然后通过乳液聚合接枝上聚甲基丙烯酸甲酯（PMMA）,再将其与甲基丙烯酸甲酯（MMA）改性的天然胶乳,通过胶乳共混法制备天然橡胶／二氧化硅纳米复合材料,结果显示,纳米二氧化硅表面接枝上了PMMA,二氧化硅在橡胶基体中分散良好,粒径在60～100nm之间,得到的胶膜力学性能有很大的提高。     

天然橡胶-伊/蒙粘土复合材料的制备与性能研究

研究天然橡胶(NR)-伊/蒙粘土(YM)复合材料(简称NR-YM)的制备与性能。结果表明:与NR相比,NR-YM的灰分质量分数较大,挥发分和氮质量分数相近;与NR胶料相比,NR-YM胶料的交联密度增大,加工安全性能、300%定伸应力、拉伸强度、耐磨性能和耐热老化性能提高;随着YM用量增大,NR-YM胶料的拉伸强度、耐磨性能和耐热氧老化性能先提高后降低;当YM用量为8份时,NR-YM胶料的综合性能最好。     

改性石墨烯/粘土/天然橡胶纳米复合材料的结构与性能

大量研究表明,纳米填料的表面效应、大的比表面积以及纳米粒子本身对基体的强界面效应对橡胶纳米复合材料性能的提升具有极大的帮助.本研究以天然橡胶(NR)为基体材料,采用乳液法制备石墨烯/粘土/NR纳米复合材料.讨论了石墨烯、粘土的用量对复合材料的物理机械性能的影响.结果 表明,当粘土用量为3.0 phr时,随着石墨烯添加量...     

乳液压力共附聚法制备纳米碳酸钙／天然橡胶复合材料的研究

采用高压均质机制备纳米碳酸钙分散体,用乳液压力共附聚法制备纳米碳酸钙/天然橡胶(NR)复合材料,并对共附聚前后混合乳液微观结构,胶膜物理性能,胶料门尼粘度、动态弹性模量(G')和损耗因子(tanδ)等进行研究.结果表明:经高压均质机处理的纳米碳酸钙分散体粒径小,分布窄,分散性好,沉降量小,贮存稳定;高压处理后纳米碳酸钙粒子与天然胶乳粒子发生了共附聚,纳米碳酸钙粒子分散良好,混合乳液胶膜物理性能明显提高;压力共附聚法制备的纳米碳酸钙/NR复合材料门尼粘度高,低应变下G'高,tanδ低,纳米碳酸钙粒子与NR之间相互作用强.     

表面改性碳纳米管/天然橡胶复合材料的制备及性能研究

采用多巴胺对多壁碳纳米管(MWCNTs)进行非共价改性,得到多巴胺改性MWCNTs(简称PCNT)。将PCNT作为填料加入天然胶乳中制备PCNT/天然橡胶(NR)复合材料,并研究其性能。透射电子显微镜(TEM)分析结果表明MWCNTs经过多巴胺改性后在水中的分散效果明显改善。PCNT/NR复合材料的拉伸强度和撕裂强度明显提高,拉伸强度由22.7 MPa升至28.4 MPa,撕裂强度由26 kN·m^-1升至40 kN·m^-1。多巴胺用量适当的PCNT在NR基体中分散更均匀,填料与橡胶的相互作用较强,能够形成较好的填料网络结构,PCNT/NR复合材料的表面电阻显著降低。     

天然橡胶/羧甲基壳聚糖抗菌复合材料的制备与性能研究

文章采用胶乳共混法制备得到了天然橡胶／羧甲基壳聚糖抗菌复合材料,并研究了材料的结构与性能。结果表明,羧甲基壳聚糖加入天然橡胶后,红外谱图上1700cm^-1。附近的吸收蜂强度发生了变化,材料的热氧化稳定忡增强,并获得了抗菌的性能,综合文章所得结果,羧甲基壳聚糖的加入量应小于4%较适宜。     

Comparative behavior of in situ silica generation in saturated rubbers: EPDM and hydrogenated natural rubber

Role of carbon‐carbon double (C?C) bonds content and their position in ethylene‐propylene diene ter‐polymer (EPDM), hydrogenated natural rubber (HNR) and natural rubber (NR) on in situ silica formation using tetraethoxysilane (TEOS) as a silica precursor is comparatively investigated. Glass transition temperature (T_g ) reflecting rubber chain flexibility is found as an important factor for in situ silica generation via swelling method. Despite of similar solubility parameters, NR has higher TEOS‐swelling degree resulting in the higher in situ silica content (30.8 phr) than EPDM (3.50 phr) and HNR (10.4–17.6 phr) due to the higher T_g of EPDM and HNR providing the less chain flexibility to be swollen in TEOS solution. The morphological analysis implies that C?C bonds in saturated rubbers may be agglomeration sites for in situ silica particles. For practical applications, saturated rubbers containing in situ silica/NR vulcanizates showed the improvement of mechanical properties and resistance of thermal and ozone degradation. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44748.     

Preparation of carbon black/natural rubber latex masterbatch in bead form

Carbon black/natural rubber latex masterbatch in the form of spherical beads was prepared according to the acid-precipitation method. High-loading carbon black (40 phr) was incorporated in natural rubber with the aid of a nonionic surfactant (Nonidet P40). Shearing the beads in an internal mixer provided good integration of carbon black in the rubber matrix and hence the high bound rubber content. Results confirmed the contribution of chemical interaction to the bound rubber content. By an oxidation process, the size of modified carbon black was reduced, whereas the large agglomeration took place in the case of partially graphitized carbon black. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 489–498, 2001     

Thermal and mechanical behavior of natural rubber latex‐silica aerogel film

A major problem in most natural rubber latex (NRL) commonly encountered like other polymer is susceptibility to mechanical properties and thermal degradation; particularly in thin film due to the presence of double bonds in the main chain. Therefore, it is desirable to seek for ways of improving these properties. Silica aerogel is a material with extraordinary properties was believed to have potential enhance properties in NRL films because of its high specific surface area. Therefore, based on the unique character of silica aerogel, NRL‐silica aerogel film was developed by latex compounding and dry coagulant dipping to form thin film where silica aerogel acts as filler. Silica aerogel, synthesized from rice husk was dispersed in a ball‐mill using distilled water for NRL compounding. Results indicate that increasing silica aerogel loading enhances the mechanical properties of the NRL‐silica aerogel film. Effects of postvulcanization processes were also investigated, whereby the best reinforcing effect was obtained at 4 phr silica aerogel loading with leaching postvulcanization condition. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

天然虾青素改性白炭黑/天然橡胶复合材料的制备与性能

采用天然虾青素对白炭黑表面进行物理改性，并与天然橡胶（NR）制备成复合材料。利用RPA、DMA、SEM等测试手段对天然虾青素改性白炭黑/天然橡胶复合材料的结构与性能进行表征。结果表明，在硫化特性方面，与未采用天然虾青素改性白炭黑相比，采用天然虾青素改性白炭黑所得胶料的焦烧时间和工艺正硫化时间均缩短，促进了橡胶的硫化过程；在物理力学性能方面，所得硫化胶的拉伸强度基本不变，回弹性和耐磨性明显增加，压缩生热降低；在动态黏弹性方面，所得硫化胶的Payne效应明显降低，填料的分散性在一定程度上得到改善；在动态力学性能方面，所得硫化胶的滚动阻力降低，玻璃化转变温度提高。特别地，在耐老化方面，天然虾青素改性白炭黑/天然橡胶复合材料的耐热空气老化性能明显提高。     

改性氨基硅溶胶/天然乳胶膜材料的制备、结构及性能

采用阳离子乳化剂聚二烯丙基二甲基氯化铵(PDDA)对氨基硅溶胶进行改性制备改性氨基硅溶胶(MSS),然后将其与天然乳胶(NRL)进行杂凝聚制得MSS/NRL膜材料,分析了MSS,MSS/NRL膜材料的结构、粒径、Zeta电位及形态,考察了MSS/NRL膜材料的力学性能及耐紫外老化性能。结果表明,MSS与NRL共混后粒径较NRL增大;氨基硅溶胶经PDDA改性后呈弱正电性,能在杂凝聚共混环境下与带负电荷的乳胶粒子形成多层次核-壳结构;随着MSS添加量的增加,MSS/NRL膜材料的拉伸强度呈先增后减的趋势,当MSS质量分数为0.35%时,膜材料的拉伸强度达到21.98 MPa的最大值,扯断伸长率达到750%;MSS/NRL薄膜的耐紫外老化性能在老化12 h以后较NRL薄膜提高10%以上。     

轮胎专用复合天然橡胶的发展趋势

轮胎专用复合天然橡胶是专门用于轮胎生产加工的天然橡胶的特殊称呼,这类橡胶产品的工艺技术是对传统的天然橡胶初加技工艺术的革新和改造。该类产品从工艺流程、产品质量、市场竞争力都比以往的天然橡胶标准产品更受下游厂家的认可,有更大的竞争优势。但它的发展也面临着重重困难,包括从原料控制、工艺监督、成品销售等方面还需要等待实践的检验、产业的规划发展等多重因素的影响。对轮胎专用复合天然橡胶的发展进行中长期发展规划,让它的发展能在市场上占有一席之地,这是对现有橡胶初加工企业的一种升级改造,也不断促进天然橡胶产业经济可持续发展。     

Reinforced chloroprene rubber by in situ generated silica particles: Evidence of bound rubber on the silica surface

Nano silica is generated in situ inside the uncrosslinked chloroprene rubber (CR) by the sol‐gel reaction of tetraethoxysilane (TEOS). This results in appreciable improvement in mechanical properties of the CR composites at relatively low filler content. Furthermore, exploitation of reactive organosilanes, γ‐aminopropyltrimethoxysilane (γ‐APS) in particular, in the silica synthesis process facilitates growing of spherical silica particles with a size distribution in the range of 20‐50 nm. The silica particles are found to be uniformly dispersed and they do not suffer from filler‐filler interaction. Additionally, it is observed that the silica particles are coated by silane and rubber chains together which are popularly known as bound rubber. The existence of the bound rubber on silica surface has been supported by the detailed investigations with transmission electron microscopy (TEM), energy filtered transmission electron microscopy (EFTEM) and energy dispersive X‐ray spectroscopy (EDAX). The interaction between rubber and silica, via bi‐functionality of the γ‐APS, has been explored by detailed FTIR studies. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43717.     

Preparation and thermal stability of brominated natural rubber from latex

The effects of pH value of reaction system, reaction time, reaction temperature, bromine concentration, and amount of potassium persulfate on the bromination reaction in the preparation of brominated natural rubber (BNR) from natural rubber latex were discussed. It has been found from the thermal analysis, that is, the thermal degradation of BNR in nitrogen is a two‐step reaction, and 16% carbonide with a stable structure remained at 470–650°C. The thermo‐oxidative degradation of BNR in air is also a two‐step reaction, and the percentage of degraded BNR reaches to nearly 100% at 600°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

热裂解气相色谱法测定天然胶乳中的干胶含量

研究热裂解气相色谱法测定天然胶乳中的干胶含量。试验结果表明,干胶含量与裂解主要产物峰面积呈现良好的线性关系,采用标准曲线法测定天然胶乳中的干胶含量,重复测定的相对标准偏差为0.14%,与国标法的平均相对误差为1.51%,定量分析结果准确,操作简便。     

Modification of isoprene rubber by in situ silica generation

BACKGROUND: The reinforcement of elastomers by the addition of fillers is one of the most important aspects in rubber science and technology. In order to optimise the filler–polymer interface, innovative in situ generation of silica within isoprene rubber was carried out by means of a bottom‐up approach through a sol–gel process starting from tetraethoxysilane as silica precursor. The main aim was the study of the effect of the silica concentration and of the presence of coupling agent on the morphology and the dynamic mechanical behaviour of the composites. RESULTS: The in situ generated silica particles were homogeneously dispersed in the vulcanised rubber with dimensions from a few nanometres to the submicrometre scale. In the presence of coupling agent a good polymer–filler adhesion was observed. The dynamic mechanical behaviour was nonlinear for silica contents higher than 20 wt%. In this range of compositions silica exerted a marked reinforcement on the low‐amplitude storage modulus, which is related to the silica content according to the Huber–Vilgis model. CONCLUSION: Isoprene rubber can be effectively reinforced by the in situ generation of silica for silica contents higher than 20 wt%, and the interaction at the silica–rubber interface can be optimised by using suitable coupling agents. Copyright © 2009 Society of Chemical Industry