杜仲粗胶对天然橡胶性能的影响

采用生物酶预处理方法对杜仲叶子进行处理,得到杜仲粗胶,研究杜仲粗胶用量对天然橡胶性能的影响。结果表明：杜仲粗胶用量超过15份时,混炼胶门尼粘度明显增大;杜仲粗胶用量对胶料的t₁₀和t₉₀影响不大;随着杜仲粗胶用量的增大,硫化胶物理性能提高,剪切储能模量降低,损耗因子增大。     

杜仲胶对天然橡胶性能影响的研究

研究了并入少量杜仲胶对天然橡胶硫化特性、力学性能以及疲劳性能的影响。结果表明,并入少量杜仲胶对天然橡胶硫化特性影响不大,可改善耐热空气老化性能,但拉伸强度有所降低,拉断伸长率变化不大,还可提高拉伸疲劳寿命和撕裂疲劳寿命。杜仲胶用量大于10份时,天然橡胶疲劳寿命有所下降;杜仲胶用量为7.5份时综合性能最好。     

硫化剂对天然杜仲胶记忆材料的性能影响

依据杜仲胶橡塑二重性,以体系内硫化剂调整其硫化胶的结晶度,实现不同硫磺用量下的杜仲胶记忆材料制备,并进行相应的力学、动态力学、热性能的表征。结果表明,当硫黄用量增加到一份时,硫化胶交联密度没有明显变化,硫黄用量超出1份以后,交联密度显著增加。定伸应力和拉伸强度随硫黄用量的增加时呈先减小而后增大趋势,拉断伸长率表现相反;同时,热致回复温度范围降低,而且在硫黄用量为1份时最小。     

水切割胶粉在胶鞋大底中的应用

采用水切割工艺制备胶粉,并将其应用于胶鞋大底中,研究了水切割胶粉用量及粒径大小对并用胶加工性能、硫化特性及物理机械性能的影响。结果表明,胶粉的加入使得混炼胶的门尼黏度升高;胶粉掺用量为10phr时对硫化特性影响较小,而用量增加到20phr时,250μm胶粉并用胶的交联密度下降,焦烧时间(t_(10))及正硫化时间(t_(90))缩短,120μm胶粉并用胶的焦烧时间缩短20s,交联密度及正硫化时间无变化;硫化胶的拉伸性能、撕裂性能及回弹性均随胶粉的掺入而降低,耐磨性提高,且硫化胶老化后性能保持率较高。     

天然杜仲胶/天然橡胶共混硫化胶的性能研究

介绍了天然杜仲胶(EUG)的基本概况、加工性能和硫化特性,研究了天然杜仲胶(EUG)/天然橡胶(NR)共混胶的硫化性能、物理机械性能和动态疲劳性能。结果表明,随着EUG用量的增大,EUG/NR共混胶焦烧时间(t10)和正硫化时间(t90)均延长,最大转矩(MH)和最小转矩(ML)均增大,定伸应力先下降后升高,拉伸强度和拉断伸长率总体下降,硬度增大,压缩温升先升高后降低,耐屈挠疲劳性能升高。当EUG用量不超过30份时,共混胶呈现出优异的耐疲劳性能、耐热空气老化性能和低生热性能。     

Si69在NR的低温长时间硫化配方中的应用研究

研究了Si69在天然橡胶（NR）的低温长时间硫化配方中对硫化胶硫化特性和力学性能的影响。结果表明：在不同的硫化温度下,随Si69用量的增加,硫化曲线平坦,返原率降低。在140℃正硫化时,硫化胶拉伸强度、定伸应力及撕裂强度较高。在145℃过硫化时,硫化胶力学性能及其保持率较高。当Si69用量为2.0份时,NR硫化胶综合性能较好。在不同硫化温度下,随硫化时间延长,NR硫化胶横向松弛时间缩短,交联密度提高。DMA结果表明,加入Si69后NR硫化胶的Tg升高。     

树脂206对CM/SBR共混胶力学性能的影响

研究了树脂206对CM/SBR共混胶硫化特性、力学性能和动态力学性能的影响。结果表明,随着树脂206用量的增大,共混胶焦烧时间缩短,正硫化时间延长,门尼粘度升高;撕裂强度、定伸应力和硬度均增大,拉伸强度变化不大,拉断伸长率略有降低。加入树脂206改善了耐热空气老化性能。随着树脂206用量的增大,混炼胶和硫化胶的储能模量均增大;应变较大时,加入树脂206可使硫化胶损耗因子降低。     

不同配比的TBzTD与DM/CZ硫化体系对“绿色”V带压缩胶老化前后力学性能及动态生热性能的影响

研究了不同配比的环保型促进剂TBzTD与DM/CZ硫化体系对V带压缩胶的老化前后物理机械性能及动态生热性能的影响。结果表明,当TBzTD的用量增加DM与CZ的用量减少,t_(10)、t_(90)变化不大,M_H-M_L有所增大。随着TBzTD的用量增加,老化前硫化胶的拉伸强度、断裂伸长率略有降低,定伸应力、硬度变化不大;100℃×24 h老化后性能保持率有所提高。随着TBzTD的用量增加,tanδ有所升高,且温度越高tanδ越小;老化时间越长,tanδ先降低后升高。     

CZ/TMTD并用量对NBR/ACM共混胶性能的影响

研究了在NBR/ACM共混胶中,使用半有效硫磺硫化体系条件下,促进剂CZ/TMTD并用量对NBR/ACM共混胶性能的影响。测试了不同CZ/TMTD并用量下NBR/ACM共混胶的硫化特性、力学性能及耐老化性能。结果表明,随着TMTD用量增大、CZ用量的减小,NBR/ACM共混胶硫化程度逐渐增大、硫化速度加快,但焦烧时间迅速减小,加工安全性变差;共混硫化胶扯断伸长率逐渐降低,硬度、拉断强度及100%定伸强度均先升高后降低;共混硫化胶耐热空气、热油老化性能均升高。     

酶辅助微生物凝固对天然橡胶性能的影响

采用酶辅助微生物凝固鲜胶乳提高天然橡胶产品性能,探究了酶用量对天然橡胶理化指标、硫化特性、加工性能、力学性能、机理及生热性能的影响。结果表明,随着酶用量的提高,生胶塑性初值和门尼黏度升高,塑性保持率降低;硫化胶正硫化时间(t₉₀)和焦烧时间(t₁₀)变短;生胶的弹性模量(G′)高,损耗因子(tan δ)小;硫化胶的拉伸强度、100%定伸应力及撕裂强度均呈上升趋势,老化处理后,硫化胶的力学性能同样保持升高的趋势;同时硫化胶温升呈下降趋势;此外,氮含量和凝胶含量有降低趋势,而丙酮溶物含量有升高趋势。     

Rheology,cure characteristics,physical and mechanical properties of tire tread reclaimed rubber/natural rubber compounds

This work aimed to examine the effect of addition of tire‐tread reclaimed rubber on the properties of two natural rubber (NR) compounds with respect to the reclaimed rubber concentration and mastication time, the properties of interest including rheological and cure characteristics, physical and mechanical properties. The results under the test conditions suggested that Mooney Plasticity and shear viscosity increased with reclaimed rubber content, but decreased with mastication time. The greater the molar mass of the natural rubber the higher the sensitivity to the change in compound viscosity due to mastication and reclaimed rubber content. The die swell was more dependent on the reclaimed rubber than the molar mass of the rubbers. The cure rate and scorch time were found to increase and decrease with reclaimed rubber content, respectively, whereas the cure time was independent of the reclaimed rubber content. For vulcanized rubbers, it was also observed that 100% modulus of the rubber increased with reclaimed rubber content, but this was not the case for tensile stress and elongation at break. The hardness and heat buildup properties of the vulcanizates increased with reclaimed rubber content whereas the tear strength became independent of the reclaimed rubber. The findings in this work suggested that the variations in the rheological and cure characteristics for the unvulcanized rubber were very much dependent on the molar mass of the rubber whereas the mechanical properties for the vulcanized rubber were influenced by crosslink density. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1723–1731, 2003     

无氨保存胶清及胶清胶性能的研究

采用水溶性、不挥发性的广谱抗菌剂——三嗪衍生物(HY)作为鲜胶乳的新型无氨保存剂,研究了HY对胶清凝固总用酸量、胶清胶及胶清胶硫化胶片性能的影响。结果表明,HY保存胶清凝固总用酸量大大减少,除氮含量略微超标外,胶清胶的各项指标均达到1级胶清胶的标准,胶清胶的塑性保持率(PRI)明显提高。HY胶清胶硫化胶片的拉伸强度和耐热氧老化能力均优于氨胶清胶硫化胶片。热解重量分析(TGA)结果表明,HY和氨胶清胶硫化胶片热氧降解均为2步反应,耐热氧降解能力基本相同。     

Systematic investigation on the effect of crosslinking agent type and dosage on the performance of TPU/MVQ based thermoplastic vulcanizates

Dynamic vulcanized thermoplastic polyurethane (TPU)/methyl vinyl silicone rubber (MVQ) thermoplastic vulcanizates (TPVs) were prepared in torque rheometer. The influence of the type and amount of peroxide crosslinking agent on the mechanical properties, thermal stability, micromorphology and melt flowability was systematically investigated. The results showed that the mechanical properties of the TPVs vulcanized by 2,5-dimethyl-2,5-di (tert-butyl peroxy) hexane (DBPH) first increased and then decreased with increasing the peroxide amount, while for dicumyl peroxide (DCP) vulcanizing system the mechanical properties slowly increased. Besides, the comprehensive mechanical properties vulcanized by DBPH were better than those of DCP group. The results of the thermogravimetric analysis showed that the TPVs vulcanized by DBPH had better heat stability, corresponding to the excellent thermo-oxidative aging performance and the 38% increase in tensile strength after aging. In addition, the MVQ rubber particles showed better dispersing performance for DBPH vulcanizing system. The melt flow rate of the TPVs showed a linear relationship with increasing DBPH dosage and became worse after the amount of crosslinking agent exceeded 1.5 phr. By comprehensive comparison, the TPVs have better performance when use peroxide DBPH as the crosslinking agent and the dosage is 1.5 phr.     

硫黄用量对天然胶乳膜性能的影响

采用凝固剂浸渍法制备天然胶乳硫化胶膜,并对其结构和性能进行研究。结果表明：天然胶乳预硫化程度随硫黄用量的增加而增大;胶膜硫化后的交联程度随硫黄用量的增加先增大后减小,在硫黄用量为1.25份时达到最大值;拉伸强度随硫黄用量的增加先增大后减小,在硫黄用量为1份时达到最大值,而拉断伸长率呈下降趋势;当硫黄用量为1份时达到最佳致密性。     

Devulcanization of Natural Rubber Vulcanizates by Mechanochemical Process

Using a suitable disulfide-based devulcanizing agent, which cleaved the sulfur cross-links in vulcanized rubber at high temperature, devulcanization of gum natural rubber was carried out. High sulfur and medium sulfur, as well as low sulfur–containing rubber vulcanizates were used to study the cleavage of sulfidic bonds. The cure characteristics and mechanical properties of vulcanized natural rubber and revulcanized natural rubber were studied. Thermal properties of the rubber were analyzed by thermogravimetric analysis (TGA), which indicates that the onset degradation temperature further increased on revulcanization with higher amount of disulfide. The properties of the revulcanized natural rubber increased with increasing disulfide concentration, also the mechanical properties of the devulcanized natural rubber were increased by decreasing the sulfur content in the original rubber vulcanizate. From the rheometric study increases in optimum cure time were observed when ground rubber vulcanizates were treated with higher amounts of disulfide. The scanning electronic microscopy (SEM) study suggested the change in failure mechanism as influenced by the type of cross-linking present and the devulcanizing agent used. From infrared (IR) spectroscopy it was observed that the oxidation of the main polymeric chain did not occur at the time of high temperature milling.     

加成型液体硅橡胶用含环氧基的有机硅增粘剂的制备、表征及性能

以烯丙基缩水甘油醚和四甲基环四硅氧烷为原料,制备加成型液体硅橡胶用含环氧基的有机硅增粘剂。用红外光谱和核磁共振氢谱对其结构进行了表征,考察了加入量对硅橡胶胶料黏度及硫化胶硬度、介电常数、介质损耗因数、绝缘电阻率、电气强度、粘接性能及封装二极管高温反向漏电流的影响。结果表明:增粘剂能提高硅橡胶的粘接强度;影响其绝缘电阻率和电气强度;降低封装二极管的高温反向漏电流;基本不影响硅橡胶胶料黏度及硫化橡胶的硬度、介电常数、介质损耗因数。     

氧化铈对双组分室温硫化硅橡胶耐热性能的影响

以二月桂酸二丁基锡为促进剂、正硅酸乙酯为硫化剂、白炭黑和氧化铈为填料制备双组分室温硫化硅橡胶,研究了氧化铈用量对双组分室温硫化硅橡胶耐热性能的影响。结果表明,氧化铈能明显提高双组分室温硫化硅橡胶的耐热性能,且其用量为8份(质量,下同)时耐热效果较好。在250℃下经72 h热空气老化后,添加了8份氧化铈的双组分室温硫化硅橡胶拉伸强度和扯断伸长率的损失率都最小。添加6份氧化铈的双组分室温硫化硅橡胶的热分解温度较未添加者提高了25.5℃,氧化铈在400～510℃时抑制了硅橡胶的热失重行为。     

环保型终止剂HSD在丁苯橡胶中的应用

研究了在室温和50℃条件下,终止剂HSD不同加料水平对丁苯橡胶乳液聚合反应的终止效果及对丁苯橡胶生胶门尼粘度和硫化胶性能的影响。结果表明,对于丁苯乳液聚合,在室温和50℃、不同加料水平条件下,HSD均具有良好的终止效果;HSD加料水平对丁苯橡胶生胶门尼粘度和硫化胶拉伸强度、扯断伸长率没有明显的影响,而对硫化胶25 min的300%定伸应力影响较大。随着HSD加料水平的增加,25 min的300%定伸应力提高。当终止剂HSD加料水平为220%时,所合成的样品可达到丁苯橡胶优级品标准,亚硝胺含量可满足欧洲环保性能指标要求。     

EPDM/iPB共混型热塑弹性体的制备与性能

通过对比不同共混比的EPDM/iPB共混体系动态硫化与未硫化的力学性能研究发现,动态硫化后的EPDM/iPB体系的性能明显优于未硫化的,当EPDM/iPB的配比为60/40、动态硫化的时间为6min时,综合性能较好;同时,研究了硫化剂和硫化时间等因素对EPDM/iPB力学性能的影响,结果表明:采用DCP/S作为硫化剂、...     

无卤阻燃型天然橡胶的研究

该文研究了阻燃剂种类和用量对天然橡胶硫化胶的阻燃性能、力学性能和硫化特性的影响。结果表明：单用氢氧化铝时,随着用量增加,硫化胶阻燃性能上升,但力学性能有所下降,氢氧化铝用偶联剂A151表面改性处理后,硫化胶力学性能有所改善;红磷作为阻燃剂用量比较少,在提高硫化胶阻燃性的同时可改善其力学性能;氢氧化铝、红磷和三氧化二锑并用可产生较好的阻燃协同效果,同时会加快橡胶的硫化速度。