Rare earth compounds modified carbon black filled powdered natural rubber: Preparation,morphology and properties

Ten types of rare earth (RE) compounds modified carbon black (HAF‐RE) were prepared using chemical‐deposit method, then HAF‐RE were mixed with natural rubber latex to prepare HAF‐RE filled powdered natural rubber [P(NR/HAF‐RE)] by a carbon black/rubber latex coagulation method. It is found that most of the P(NR/HAF‐RE) vulcanizates showed better mechanical properties, especially higher tensile modulus, and tensile strength, compared with none‐rare earth modified carbon black filled powdered natural rubber [P(NR/HAF)]. Dysprosium (Dy) modified carbon black (HAF‐Dy) filled powdered natural rubber [P(NR/HAF‐Dy)] was chosen for intensive investigation because of its better comprehensive mechanical properties. It is found that the adding of Dy compounds could help to get smaller particles with narrower particle size distribution, and results from the SEM analysis show that carbon black has been dispersed in rubber matrix uniformly with diameter of 50–150 nm. The TEM analysis showed that Dy compounds could obviously reduce the aggregation of primary particles of carbon black, and promote the dispersion of carbon black in P(NR/HAF‐Dy) particles. © 2008 Wiley Periodicals, Inc. JAppl Polym Sci 2008     

Particle size distribution,mixing behavior,and mechanical properties of carbon black (high‐abrasion furnace)–filled powdered styrene butadiene rubber

High‐abrasion furnace black (HAF, grade N330)–filled powdered styrene butadiene rubber [P(SBR/HAF)] was prepared and the particle size distribution, mixing behavior in a laboratory mixer, and mechanical properties of P(SBR/HAF) were studied. A carbon black–rubber latex coagulation method was developed for preparing carbon black–filled free‐flowing, noncontact staining SBR powders, with particle diameter less than 0.9 mm, under the following conditions: carbon black content > 40 phr, emulsifier/carbon black ratio > 0.02, and coating resin content > 2.5 phr. Over the experimental range, the mixing torque τ_α of P(SBR/HAF) was not as sensitive to carbon black content and mixing temperature as that of HAF‐filled bale SBR (SBR/HAF), whereas the temperature build‐up ΔT showed little dependency on carbon black content. Compared with SBR/HAF, P(SBR/HAF) showed a 20–30% mixing energy reduction with high carbon black content (>30 phr), which confers to powdered SBR good prospects for internal mixing. Carbon black and the rubber matrix formed a macroscopic homogenization in P(SBR/HAF), and the incorporation step is not obvious in the internal mixing processing results in these special mixing behaviors of P(SBR/HAF). A novel mixing model of carbon black–filled powdered rubber, during the mixing process in an internal mixer, was proposed based on the special mixing behaviors. P(SBR/HAF) vulcanizate showed better mechanical properties than those of SBR/HAF, dependent primarily on the absence of free carbon black and a fine dispersion of filler on the rubber matrix attributed to the proper preparation conditions of noncontact staining carbon black–filled powdered SBR. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2494–2508, 2004     

Dispersion of carbon black in high‐abrasion furnace black filled nonsulfur modified powdered polychloroprene rubber

High‐abrasion furnace black (HAF, grade N330) filled nonsulfur modified powdered polychloroprene rubber [P(CR231/HAF)] was prepared with the method of carbon black–rubber latex coagulation using CR231 latex as raw rubber material, HAF as reinforcing filler, and polymeric resin as coating resin. The influence of the content of dispersing agent and coating resin on contact staining and dispersion properties of carbon black in P(CR231/HAF) were investigated. The results show that the addition of dispersing agent and coating resins can decrease the contact staining level of carbon black effectively. When the dispersing agent/HAF (w/w) ratio was 0.12 or 0.1, 10 phr coating resin was added, and P(CR231/HAF) without contact staining can be prepared. The analysis on scanning electron microscopy and surface energy spectrum showed that free carbon black crumb on the surface and inner of P(CR231/HAF) particles causes its contact staining. The well dispersion of carbon black in the P(CR231/HAF) can eliminate contact staining effectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 192–196, 2006     

稀土掺杂炭黑填充型粉末天然橡胶（Ⅱ）微观结构与成粉机理

采用扫描电镜（SEM）和透射电镜（TEM）对稀土镝掺杂炭黑填充型粉末天然橡胶EP（NR／HAF—Dy）]颗粒进行表面和截面微观分析,发现稀土镝掺杂炭黑（HAF—Dy）已在橡胶基体中形成良好分散,其平均分散粒径达到50～200nm。在此基础上,结合P（NR／HAF—Ln）的制备工艺,提出了P（NR／HAF—Dy）的成粉机理模型,认为在水相中良好分散的HAF—Dy与NR乳胶粒结合所形成的NR／炭黑凝胶网络粒子是构成P（NR／HAF—Dy）的基本单元,这也是HAF—Dy能在NR中形成纳米级分散的主要原因。     

Mechanical properties and crosslink density of rare earth‐modified high‐abrasion furnace‐filled powdered natural rubber

High‐abrasion furnace‐filled powdered natural rubber [P(NR/HAF)] has more advantages than traditional HAF‐filled bale NR (NR/HAF) because of its better environmental performance and easier processing quality, but its lower mechanical properties are disadvantageous. To improve the mechanical properties, rare earth‐modified HAF‐filled powdered NR [P(NR/HAF‐Ln)] (Ln = Sm,La,Pr) was prepared by means of coacervation–coprecipitation, using rare earth‐modified HAF as separant and filler. The effect on mechanical properties of P(NR/HAF‐Ln) vulcanizate exerted by the emulsifier/HAF ratio, powdering temperature, Ln/HAF ratio and type of Ln, and HAF content were studied. The results indicated that when optimum formulation, the mechanical properties of P(NR/HAF‐Ln) vulcanizate were better than P(NR/HAF) vulcanizate. In addition, the relationship of the apparent crosslink density and HAF content of P(NR/HAF‐Ln), P(NR/HAF), NR/HAF vulcanizates was also investigated, along with their SEM microphotographs of tensile fracture surface, which indicated that the excellent mechanical properties of P(NR/HAF‐Ln) vulcanizate was attributed to correct amount of Ln that could increase crosslink density and reinforce the interface structure of NR matrix/HAF‐Ln particle. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1755–1762, 2006     

高耐磨炭黑填充型粉末NR研究(Ⅲ)硫化胶的物理机械性能

研究了高耐磨炭黑(N330)填充型粉末天然橡胶[P(NR/N330)]硫化胶的物理机械性能.结果发现炭黑乳化剂、炭黑、操作油和包覆剂的用量及玻璃化转变温度对P(NR/N330)硫化胶的物理机械性能的影响比较明显.在适宜的粉末化条件下制备的P(NR/N330),其硫化胶的物理机械性能优于天然胶乳与炭黑的简单共沉胶(ENR/N330),而300%定伸应力则低于块状NR/N330机械混炼胶(MNR/N330).P(NR/N330)硫化胶拉伸断面形貌的SEM分析表明,包覆剂在用量为15份时,与NR基体形成互锁结构;DSC分析表明,二者部分相容,因此硫化胶具有较好的物理机械性能.     

稀土掺杂炭黑填充型粉末天然橡胶（I）制备与粒径分布

利用稀土（Ln）可与有机高分子化合物发生作用的性质。用稀土盐和炭黑以液相化学沉积法制备了稀土化合物掺杂炭黑（HAF—Ln）,以增加炭黑粒子的表面活性,并将其与天然胶乳（NRL）共混,采用凝聚共沉法制备稀土掺杂炭黑填充型粉末天然橡胶[P（NR／HAF—Ln）]。透射电镜（TEM）、傅立叶转换红外光谱（FTIR）、等离子发射光谱（ICP）分析表明,稀土可全部沉积到炭黑粒子表面;稀土可有效减少炭黑粒子的团聚,促进炭黑在水中的稳定分散。稀土的加入可提高NR胶乳与乳化炭黑构成的粉末体系的成粉率。     

The mastication characteristics of powdered carbon black filled natural rubber during internal mixing

Powdered carbon black filled natural rubber, P(NR/HAF), is a premixture of natural rubber and carbon black in powdered form with good carbon black dispersion throughout the rubber matrix. In this study, the mastication properties of P(NR/HAF) were observed under a wide temperature range (50–110°C) and rotor speed (30–100 rpm) range, using a mixing head attached to Brabender Plasticorder. It was found that P(NR/HAF) showed different mastication characteristic, compared to the traditional internal mastication theories of natural rubber; poor masticating properties of P(NR/HAF) are observed with low rotor speed and high temperature and a ‘‘stable zone’’ with middle rotor speed and lower temperature. The Mooney viscosity of rubber batch under different rotor speed and temperature was almost the same, and mastication properties were unsatisfactory. It was considered that the higher temperature build‐up of the mixing batch of P(NR/HAF) during the early stage of internal mixing results in the special mastication properties. A quadratic mastication model of P(NR/HAF), based on the multivariate regression analysis and stepwise regression analysis, was used to predict the mastication characters of P(NR/HAF) in internal mixer under varied temperature and rotor speed. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

炭黑填充型粉末天然橡胶的密炼机塑炼特性研究

采用实验室微型密炼机（Brabender转矩流变仪）研究了炭黑填充型粉末天然橡胶[P（NR/HAF）]的密炼机塑炼/混炼性能,即塑炼时间、塑炼温度和转速等基本工艺参数对胶料门尼粘度的影响。与传统的块状天然橡胶/炭黑（NR/HAF）的密炼机混炼相比,P（NR/HAF）在密炼机混炼时具有较高的混炼温升和较快的升温速率,使得胶料在较高的温度下被塑炼,从而表现出与传统的NR/HAF不同的密炼机混炼特性,其最佳塑炼温度有所降低。通过逐步回归分析建立的“门尼粘度-塑炼条件”模型可以较好地拟合和预测不同塑炼条件下P（NR/HAF）密炼机塑炼后胶料的门尼粘度。     

用作载重子午线轮胎胎面胶的炭黑填充粉末NR结构与性能研究

以天然胶乳和炭黑N234为原料,采用凝聚共沉法制备炭黑填充型粉末NR[P(NR/CB)],研究炭黑用量和不同配方对胶料硫化特性、物理性能、交联密度、微观结构、Payne效应及动态力学性能的影响,并与采用传统机械混炼法制备的炭黑/NR(CB/NR)进行对比.结果表明,与CB/NR硫化胶相比,P(NR/CB)硫化胶具有较高的拉伸强度、撕裂强度、回弹值和抗湿滑性能以及较低的滚动阻力,耐屈挠性能和耐磨性能大致相当,而动态压缩生热和压缩永久变形则降低了近50%.     

稀土掺杂高耐磨炭黑填充型粉末NR研究——Ⅰ．硫化胶的物理机械性能

以天然胶(NR)乳为原料，稀土化合物改性高耐磨炭黑N330(N330-Re)为填充隔离剂，用凝聚共沉法制备了稀土掺杂高耐磨炭黑填充型粉末NR[P(NR／N330-Re)]，研究了炭黑乳化剂用量、粉末化温度、硫磺用量、稀土元素的种类及用量、过渡金属Zn的用量、N330-Re的用量等因素对其硫化胶物理机械性能的影响。结果表明，所选用的稀土化合物对高耐磨炭黑N330具有优良的改性效果，从而对P(NR／N330-Re)硫化胶有显著的补强作用，其中以Sm2O3与La2O3改性效果最佳。     

高耐磨炭黑填充型粉末SBR研究Ⅱ.硫化胶的物理机械性能

研究了高耐磨炭黑(N330)填充型粉末丁苯橡胶[P(SBR／N330)]硫化胶的物理机械性能。结果发现。炭黑乳化剂的用量、炭黑改性剂和包覆剂的用量及玻璃化转变温度对P(SBR／N330)硫化胶的物理机械性能的影响比较明显。在适宜的粉末化条件下制备的P(SBR／N330)，其硫化胶的物理机械性能与块状SBR／N330通过机械混炼得到的硫化胶的物理机械性能处于相同水平。P(SBR／N330)硫化胶拉伸断面形貌的SEM分析表明，包覆剂在用量为5份时形成的粒子与SBR基体结合紧密，在用量为15份时形成的粒子较易剥离。     

掺杂氧化钐的炭黑用量对粉末天然橡胶性能的影响

高耐磨炉黑(HAF)填充型粉末天然橡胶(NR)[P(NR/HAF)]硫化胶的缺点是300%定伸应力低,因此,采用Sm2O3掺杂HAF(HAF-Sm),用凝聚共沉法制备了掺杂Sm2O3的HAF填充型粉末天然橡胶(NR)[P(NR/HAF-Sm)],研究了其硫化胶的力学性能与Sm2O3及HAF用量之间的关系。结果表明:在炭黑用量为10~100份,当炭黑用量相同、Sm2O3的质量分数为HAF的3%时,其P(NR/HAF-Sm)硫化胶的300%定伸应力显著高于P(NR/HAF)硫化胶,而与块状NR(MNR)/HAF机械混炼胶料硫化胶的相近;其拉伸强度、100%定伸应力和撕裂强度明显高于P(NR/HAF)及MNR/HAF硫化胶。这说明适量的Sm2O3掺杂HAF可显著提高炭黑填充型粉末NR硫化胶的300%定伸应力及其他力学性能。     

高耐磨炉黑填充粉末丁腈橡胶的制备及性能

研究了利用高分子树脂凝聚包覆法制备高耐磨炉黑填充粉末丁腈橡胶的制备过程及其影响硫化胶物理机械性能的因素。结果表明，当分散剂／包覆剂(质量比)为4／6或10／4时，粒径不大于0．90mm的粉末丁腈橡胶粒子的质量分数为100．0％，相应硫化胶的物理机械性能达到块状丁腈橡胶硫化胶的。高耐磨炉黑填充粉末丁腈橡胶硫化胶的物理机械性能极大地依赖于高耐磨炉黑粒子在基体橡胶中的分散程度及其与基体黏结的紧密性。     

环氧树脂增强天然橡胶/顺丁橡胶并用胶的性能

采用低相对分子质量的液体环氧树脂(EP)与固化剂混合作为增强体的前驱体,比较了其填充天然橡胶(NR)、顺丁橡胶(BR)及两者并用胶的物理机械性能,考察了EP用量对并用胶及炭黑增强并用胶物理机械性能的影响,并通过扫描电子显微镜表征了填充后的NR、BR及并用胶的微观相态结构。结果表明,EP的加入均可提高NR、BR、NR/BR并用胶的物理机械性能,其中并用胶的拉伸强度提高幅度最大;当EP用量约为24份时,NR/BR并用胶的综合性能最佳;EP可以提高炭黑增强NR/BR并用胶的物理机械性能,但提高幅度不大;EP在NR/BR并用胶中呈现规整的圆球形状,直径为1.0～2.5μm。     

稀土掺杂炭黑填充型非硫调节型粉末氯丁橡胶的性能与结构

利用镧系稀土（Ln）对炭黑表面有特殊的活化作用,采用化学沉积法制备了稀土掺杂炭黑（HAF—Ln）,并将HAF—Ln与非硫调节型氯丁胶乳（CR232胶乳）进行共混,采用凝聚共沉法制备了稀土掺杂炭黑填充型非硫调节型粉末氟丁橡胶[P（CR232／HAF—Ln）]。研究了稀土类型及用量对P（CR232／HAF—Ln）硫化胶力学性能的影响,发现采用稀土La、Sm和Tm掺杂的P（CR232／HAF—Ln）具有较好的力学性能。通过P（CR232／HAF—Ln）硫化胶拉伸断面的SEM分析,发现稀土La、Sm和Tm可有效改善炭黑在橡胶基体中的分散。     

SBR/高耐磨炭黑的共混方式对其硫化胶性能的影响

测定了高耐磨炭黑填充型粉末SBR[P(SBR/HAF)],SBR胶乳/炭黑共沉胶(ESBR/HAF)和SBR块胶/炭黑机械混炼胶(MSBR/HAF)3种不同共混方式的硫化胶的力学性能.结果发现,在炭黑填充量相同的条件下,3种硫化胶的定伸应力和拉伸强度的大小顺序为MSBR/HAF＞P(SBR/HAF)＞ESBR/HAF,撕裂强度及扯断永久变形的大小顺序为ESBR/HAF＞P(SBR/HAF)＞MSBR/HAF.拉伸断面形貌的SEM分析表明,MS-BR/HAF硫化胶以微裂纹导致基体空化,P(SBR/HAF)以既有微裂纹导致基体空化又有裂缝扩展及分支,ES-BR/HAF则以裂缝扩展及分支的方式断裂.     

Distribution of carbon black in natural rubber/acrylic rubber blends

Distributions of carbon black in 30/70% (w/w) natural rubber (NR)/acrylic rubber (ACM) blends were investigated as a function of the carbon black content and type using a dynamic mechanical thermal analysis (DMTA) technique. Two different types of carbon black (N220 and N330) were used, and 10–50 phr carbon black was compounded to the rubber blends. From the DMTA thermograms of various blends, the weight fractions of carbon black in the NR and ACM phases were calculated. Carbon black was unevenly distributed in the rubber blend. It preferred to migrate into the NR phase, regardless of the amount of carbon black that was used. By increasing the carbon black content, the weight fraction of carbon black in the NR phase decreased whereas that in the ACM phase increased. A change in the type of carbon black from N220 to N330 significantly decreased the weight fraction of carbon black in the NR phase, but it was not sufficiently strong to affect the tensile properties and hardness of the rubber blend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:248–256, 2006     

高耐磨炉黑填充型粉末丁腈橡胶硫化胶的老化性能

研究了高耐磨炉黑(HAF)填充型粉末丁腈橡胶[P(NBR/HAF)]硫化胶的热空气老化、耐异辛烷/甲苯溶剂及压缩永久变形性能,并与机械混炼的块状丁腈橡胶(BNBR)/HAF硫化胶进行比较。结果表明:P(NBR/HAF)硫化胶的耐热空气老化、耐溶剂及压缩永久变形性能受高分子树脂包覆剂及其用量的影响;P(NBR/HAF)硫化胶的上述性能达到或超过BNBR/HAF硫化胶。     

炭黑并用对NR／ENR共混胶力学性能及减震性能的影响

对比N660研究了N330／N660、N660／N990炭黑填充体系对天然橡胶（NR）／环氧化天然橡胶（ENR）共混胶力学性能、压缩疲劳生热性能及减震性能的影响,并采用橡胶加工分析仪（RPA）对其加工性能进行了分析。结果表明：N660／N330和N660／N990两种填充体系硫化胶的力学性能,基本上是单用一种炭黑所得硫化胶力学性能的加权平均;不同粒径炭黑并用均能使共混胶的贮能模量E′下降,并且有利于拓宽NR／ENR减震材料的减震范围;不同粒径炭黑并用有利于改善NR／ENR共混胶料的加工性能。