丁基橡胶预硫化对天然橡胶/丁基橡胶复合材料性能的影响

研究了预硫化丁基橡胶对天然橡胶/丁基橡胶复合材料性能的影响。结果表明,与丁基橡胶未经预硫化的天然橡胶/丁基橡胶复合材料相比,由于交联网络结构得到完善,预硫化天然橡胶/丁基橡胶复合材料的硫化最大转矩提高,拉伸强度、扯断伸长率和撕裂强度大幅度增加;天然橡胶与丁基橡胶的并用质量比为70/30时,复合材料的拉伸强度增至7.9 MPa,提高了61%,撕裂强度提高了33%。丁基橡胶经过预硫化后,天然橡胶/丁基橡胶复合材料两相的分散效果得到明显改善,玻璃化转变温度升高;同时,预硫化对于复合材料阻尼性能的影响则与丁基橡胶的共混比相关。     

胶粉/乙烯-辛烯共聚物复合材料的性能

考察了硫化剂过氧化二异丙苯(DCP)对胶粉/乙烯-辛烯共聚物(POE)复合材料硫化特性及物理机械性能的影响,对比了白炭黑与硅藻土对复合材料的增强效果,并研究了白炭黑填充复合材料的耐老化性能。结果表明,当胶粉/POE(质量比)为30/70时,随着DCP用量的增加,正硫化时间逐渐缩短;当DCP用量为2份、硫化时间约为780 s时,胶粉/POE复合材料的综合性能最佳;随着白炭黑用量的增加,胶粉/POE复合材料的拉伸强度和撕裂强度提高,扯断伸长率逐渐降低;随着硅藻土用量的增加,胶粉/POE复合材料的物理机械性能稍呈下降趋势,说明白炭黑的增强效果优于硅藻土;随着白炭黑用量的增加,胶粉/POE复合材料的耐老化性能提高。     

环氧化天然橡胶改性的丁苯橡胶/白炭黑复合材料的形态和性能

以环氧化天然橡胶为改性剂制备了丁苯橡胶/白炭黑复合材料,研究了环氧化天然橡胶对丁苯橡胶/白炭黑复合材料微观形态和力学、耐热、耐老化及动态力学性能的影响.结果表明,少量环氧化天然橡胶的加入改善了填料在橡胶基质中的分散,提高了丁苯橡胶/白炭黑复合材料硫化胶的定伸应力、拉伸强度、撕裂强度和耐磨性能,降低了其动态压缩疲劳生热速...     

甲基丙烯酸羟乙酯接枝天然橡胶对白炭黑/天然橡胶复合材料性能的影响

研究甲基丙烯酸羟乙酯（HEMA）接枝天然橡胶（NR）（NR-g-HEMA）接枝率和用量对白炭黑/NR复合材料性能的影响。结果表明：与未加入NR-g-HEMA的白炭黑/NR复合材料相比,加入NR-g-HEMA的白炭黑/NR复合材料的硫化速度、交联程度、邵尔A型硬度、定伸应力和撕裂强度增大,压缩疲劳生热明显降低;当NR-g-HEMA接枝率为10%和用量为10份时,白炭黑/NR复合材料的拉伸强度最大,压缩疲劳生热最低;NR-g-HEMA与NR相容性较好,加入NR-gHEMA的白炭黑/NR复合材料中白炭黑在橡胶相中分散更均匀,两者具有更强的界面结合效果。     

壳聚糖改性二氧化硅/天然橡胶复合材料的性能

采用溶胶-凝胶法制备了壳聚糖改性二氧化硅,并采用共沉降法制备了壳聚糖改性二氧化硅/天然橡胶（NR）复合材料,考察了壳聚糖用量对复合材料硫化特性、拉伸性能、耐老化性能的影响,并用扫描电子显微镜观察了拉伸试样的断面形貌。结果表明,壳聚糖的加入使NR复合材料的性能得到明显改善,当其用量为0.5 g时,复合材料的硫化特性与拉伸性能最佳,正硫化时间为1.95 min,拉伸强度为24.01 MPa,扯断伸长率达到256%;当壳聚糖添加量为0.3 g时,硫化胶的拉伸强度与扯断伸长率的性能保持指数最高,耐老化性能最佳;经壳聚糖改性的二氧化硅在NR中的分散性得到改善。     

造纸黑液干粉用量对PVC/CPE热塑性弹性体性能的影响

以造纸黑液经硫酸中和处理脱水后的黑液干粉为填料,采用熔融共混法制备了聚氯乙烯(PVC)/氯化聚乙烯(CPE)/黑液干粉热塑性弹性体复合材料。利用FTIR和TGA测试了黑液干粉的结构和热性能;利用微控电子万能试验机、TGA研究了黑液干粉含量对弹性体复合材料的力学性能、热降解性能和老化性能的影响。结果表明:黑液干粉中木质素等有机物含量为33%;添加黑液干粉能改善PVC/CPE弹性体复合材料的力学性能,当黑液干粉含量为30phr时,拉伸强度保持不变,断裂伸长率提高了8%,撕裂强度提高了5%;采用硬脂酸处理的黑液干粉,其用量为30phr时,复合材料综合性能较佳,其拉伸强度提高了7%,断裂伸长率提高了12%,撕裂强度提高了18%;黑液干粉含量30phr时,PVC/CPE弹性体复合材料热降解温度提高了5℃;添加黑液干粉的复合材料,在热氧老化后拉伸强度和邵尔A型硬度增加,断裂伸长率稍有下降。     

乙烯-醋酸乙烯共聚物对天然橡胶/丁腈橡胶并用胶性能的影响

研究了EVA(乙烯-醋酸乙烯共聚物)对天然橡胶(NR)/丁腈橡胶(NBR)并用胶硫化特性、力学性能、阻尼性能、压缩生热的影响。结果表明:随着EVA含量的增多,NR/NBR并用胶的硫化速度先升后降;拉伸强度降低,撕裂强度则先增加后下降,硬度增加,回弹性降低;NR/NBR并用胶在拉伸/压缩-恢复过程中的HED和HLE均先减少后增大; DMA谱图中NR与NBR相损耗峰均移向低温,有效阻尼温域拓宽;压缩永久变形和疲劳温升增加。     

偶联剂改性生化木质素在天然橡胶中的应用研究

采用乳液共沉法制备天然橡胶/生化木质素/白炭黑(NR/BCL/白炭黑)复合材料,研究了硅烷偶联剂四硫化双(三乙氧基丙基)硅烷(Si-69)用量对复合材料门尼黏度、硫化特性、物理机械性能、填料分散性及动态热机械性能的影响。结果表明,随着Si-69用量的增加,混炼胶的焦烧时间缩短,硫化时间延长,硫化程度增加;当Si-69用量不超过4份时,混炼胶的填料分散性变化不大;硫化胶的拉伸强度、100%与300%定伸应力先增加后下降,断裂伸长率先下降后增加,撕裂强度、硬度均有所增加,当Si-69用量为4份时,硫化胶的综合力学性能最佳;硫化胶的损耗因子峰值增大,当Si-69用量为4份时,滚动阻力最低,但抗湿滑性相对较差。     

PP/硅藻土复合材料拉伸性能的研究

考察了硅藻土粒径和含量对填充聚丙烯复合材料的拉伸性能的影响。结果表明,当硅藻土体积分数时,复合材料的拉伸强度和断裂强度都有所下降,然后,两者均有轻微的提高;除个别测量点外,复合材料的断裂伸长率随着的增加而明显增大;当时,硅藻土粒径为7μm的填充体系的拉伸强度和拉伸断裂强度最高。     

纳米Al2O3/炭黑并用增强天然橡胶

研究了不同并用比纳米Al2O3/炭黑填料对天然橡胶硫化胶性能的影响。分析了填料－橡胶的相互作用。结果表明，当Al2O3／炭黑质量比为1／1时，天然橡胶硫化胶的拉伸强度和撕裂强度最高，当Al2O3／炭黑质量比为3／1时，天然橡胶硫化胶的耐磨性和耐疲劳性能最佳，填料与橡胶朴素作用中的氢键是影响天然橡胶硫化胶疲劳性能的重要因素，共价键是影响其拉伸强度的重要因素。     

Physical properties of natural rubber/organoclay nanocomposites compatibilized with epoxidized natural rubber

Onium ion‐modified montmorillonite (organoclay) was melt compounded with natural rubber (NR) in an internal mixer and cured by using a conventional sulfuric system. Epoxidized natural rubber with 50 mol % epoxidation (ENR 50) was used in 10 parts per hundred rubber (phr) as a compatibilizer. The effect of organoclay with different filler loading up to 10 phr was studied. Cure characteristics were determined by a Monsanto MDR2000 rheometer, whereas the tensile, compression, and tear properties of the nanocomposites were measured according to the related ASTM standards. While the torque maximum and torque minimum increased slightly, both scorch time and cure time reduced with the incorporation of organoclay. The tensile strength, elongation at break, and tear properties went through a maximum (at about 2 phr) as a function of the organoclay content. As expected, the hardness, moduli at 100% (M100) and 300% elongations (M300) increased continuously with increasing organoclay loading. The compression set decreased with incorporation of organoclay. The dispersion of the organoclay in the NR stocks was investigated by X‐ray diffraction and transmission electron microscopy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1083–1092, 2006     

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...     

天然橡胶增韧聚氯乙烯的研究

采用未改性的标准天然橡胶(NR)作增韧剂,通过机械共混法制备增韧聚氯乙烯(PVC)复合材料,考察了NR和增容剂用量对PVC增韧效果以及力学性能的影响.结果表明:当NR用量为10份时,材料的冲击强度最高为24.87 kJ/m2;加入增容剂环氧化天然橡胶(ENR)后,材料的冲击强度随其用量的增加而增大,在ENR为5份时其冲击强度为69.86 kJ/m2;氯化聚乙烯(CPE)作增容剂时,其冲击强度先升后降,在4份时达到峰值103.93 kJ/m2;氯化橡胶(CNR)作增容剂在3份时,其冲击强度达到最佳值35.37 kJ/m2;增容增韧后共混物的拉伸强度普遍降低.     

On the potential of organoclay with respect to conventional fillers (carbon black,silica) for epoxidized natural rubber compatibilized natural rubber vulcanizates

Onium modified montmorillonite (organoclay) was compounded with natural rubber (NR) in an internal mixer and cured by using a conventional sulfuric system. Epoxidized natural rubber with 50 mol % epoxidation (ENR 50) in 10 parts per hundred rubber (phr) was used as a compatibilizer in this study. For comparison purposes, two commercial fillers: carbon black (grade N330) and silica (grade vulcasil‐S) were used. Cure characteristics were carried out on a Monsanto MDR2000 Rheometer. Organoclay filled vulcanizate showed the lowest values of torque maximum, torque minimum, scorch, and cure times. The kinetics of cure reaction showed organoclay could behave as a cocuring agent. The mechanical testing of the vulcanizates involved the determination of tensile and tear properties. The improvement of tensile strength, elongation at break, and tear properties in organoclay filled vulcanizate were significantly higher compared to silica and carbon black filled vulcanizates. In terms of reinforcing efficiency (RE), organoclay exhibited the highest stiffness followed by silica and carbon black filled vulcanizates. Scanning electron microscopy revealed that incorporation of various types of fillers has transformed the failure mechanism of the resulting NR vulcanizates compared to the gum vulcanizates. Dynamic mechanical thermal analysis (DMTA) revealed that the stiffness and molecular relaxation of NR vulcanizates are strongly affected by the filler–rubber interactions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2438–2445, 2004     

聚乙烯醇/天然橡胶共混物的制备及其性能研究

利用环氧化天然胶乳作为界面改性剂,采用胶乳共混法将聚乙烯醇（PVA）溶液同天然胶乳进行混溶,制备了PVA/天然橡胶（NR）的共混物,通过电子万能材料试验机、动态热机械分析仪、热老化箱和臭氧老化箱,研究了共混物力学性能、玻璃化转变温度、老化性能以及耐溶剂抽出性。结果表明,PVA的加入明显提高了NR的撕裂强度和硬度,而共混物的拉伸强度和断裂伸长率随着PVA含量的增加都出现下降的趋势;随着PVA含量的增加,NR的玻璃化转变温度呈现先增加后降低的趋势;随着PVA含量增加,共混物各试样对乙醇的耐抽出能力相差不大,对水的耐抽出能力逐步变弱。热空气老化对材料的力学性能影响明显,而臭氧老化由于时间较短,对材料的力学性能影响不明显。老化实验对材料的性能变化率影响显著。     

NR/SBR并用胶配比对其硫化特性和力学性能的影响

考察了天然橡胶与丁苯橡胶不同配比对并用胶硫化特性和力学性能的影响.无转子硫化仪的测试结果表明,随着丁苯橡胶的占比增加,最小转矩和最大转矩均变大,且两者差值也随之增大,硫化时间延长,硫化胶的拉伸强度和撕裂强度明显下降,硬度增加;120℃老化后拉伸强度有不同程度的下降,天然橡胶占比越多下降越明显.     

Mechanical and morphological properties of cellular NR/SBR vulcanizates under thermal and weathering ageing

The effects of addition of two chemical blowing agents in cellular rubber blend of natural rubber (NR) and styrene‐butadiene rubber (SBR) at a fixed blend ratio of 1 : 1 on cure characteristics, and mechanical and morphological properties were invesigated. The chemical blowing agents used in this work were Oxybis (benzene sulfonyl) hydrazide (OBSH) and Azo dicarbonamide (ADC). Three different fillers, fly ash (FA) particles, precipitated silica, carbon black (CB) at their optimum concentrations of 40 phr were used, the FA and silica particles being chemically treated by bis‐(3‐triethoxysilylpropyl) tetrasulphide. The results suggested that the overall cure time decreased with OBSH and ADC contents. The OBSH was more effective in cure‐acceleration of the NR/SBR blend than the ADC. The NR/SBR vulcanized foams produced by OBSH and ADC agents had closed‐cell structures. The specific density and mechanical properties of the blend tended to decrease with increasing blowing agent content. The CB gave NR/SBR foams with smaller cell size, better cell dispersion, and higher mechanical properties than the precipitated silica and FA particles. The heat ageing and weathering resulted in an increase in tensile modulus and hardness, but lowered the tensile strength, ultimate elongation and tear strength. The elastic recovery for cellular NR/SBR vulcanizates with FA was superior to that with CB and silica, the elastic recovery of the blends decreasing with blowing agent content. Resilience property was improved by the presence of gas phases. The optimum concentration of OBSH and ADC to be used for NR/SBR vulcanizates was 4 phr. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

炭黑/煤矸石/碳纳米管复合填料体系对天然橡胶性能的影响研究*

利用硝酸氧化法对碳纳米管(CNTs)进行纯化,并用环氧天然橡胶(ENR)进行改性处理。结合胶质量分数测定结果表明, ENR用量15%(质量)时效果最佳。采用胶乳凝聚法制备CNTs/天然橡胶(NR)母料。煤矸石粉(CG)经高温煅烧和表面改性处理。 将CNTs/天然橡胶(NR)母料、CG和炭黑(CB)通过机械混炼法与天然橡胶及配合剂混合,制备CB/CG/CNTs/NR复合材料,并对复合材料进行硫化特性及物理机械性能。结果表明： CNTs延迟硫化效应明显;相比炭黑,CG对硫化具有促进作用。硫化特性和甲苯溶胀法测定结果表明,在填料份数相同的条件下,单独由CB填充的NR有最大的交联密度,CNTs对交联密度影响不明显。物理机械性能测试结果表明,当CG：CB：CNTs=17.5:16.5:1(Phr)时,NR硫化胶的300%定伸应力和扯断伸长率明显高于单独由CB填充NR,而拉伸强度与之接近,复合填料样填充NR具有较好的综合性能。扫描电镜测试结果表明,复合填料在NR基体中分布均匀。     

硅藻土/白炭黑复合填料的补强性研究

为拓展硅藻土在高分子复合材料中的应用,将硅藻土/白炭黑填充到天然橡胶/丁苯橡胶/顺丁橡胶中制备了复合材料。通过RPA2000和扫描电镜分析了复合填料的Payne效应和分散性,考察了硅藻土用量对复合材料工艺性能、力学性能、耐磨耗性能影响。结果表明:少量硅藻土的加入有利于白炭黑在橡胶中的分散,能降低复合材料的门尼粘度和Payne效应,提高复合材料的硫化速度,缩短硫化时间,复合填料的补强效果较好;随着硅藻土用量的增加,复合填料容易聚集,其力学性能呈下降趋势,而磨耗性能变化不大;当硅藻土用量10~20份时,复合材料的综合性能最好。     

CURE CHARACTERISTICS AND MECHANICAL PROPERTIES OF NATURAL RUBBER/RECLAIMED RUBBER BLENDS

Cure characteristics and mechanical properties of natural rubber/reclaimed rubber blends were studied. The minimum torque values of the blends were lower than that of the gum compound. The (maximum–minimum torque) and scorch time decreased with increasing reclaim content. The cure rate of the blends were lower than that of the virgin compounds. The tear strength was improved by the addition of reclaimed rubber. Tensile strength, elongation at break, and resilience decreased with increasing reclaim loading. The heat buildup was higher for the blends.