共混比对NR/NBR阻尼材料性能的影响

研究了天然橡胶/丁腈橡胶(NR/NBR)两相共混比对共混胶阻尼材料硫化特性、力学性能、压缩生热以及阻尼性能的影响。结果表明:随着NBR含量增加,共混胶M_L、M_H、M_H-M_L均增大,t_(s1)和t_(c90)先缩短后延长;共混胶拉伸强度、拉断伸长率、定伸应力和撕裂强度均减小,硬度有所增大,回弹性明显下降;压缩永久变形和温升明显增大;滞后能量损耗(HED)和阻尼系数增大。DMA曲线上表现出两个明显的损耗峰,随着NBR含量增加,NR相峰值tanδ_(max1)下降而NBR相损耗峰值tanδ_(max2)逐渐增大,损耗模量的变化趋势与之相似。NBR/NBR=70/30时,共混胶力学性能相比纯NR下降程度低,且室温附近的阻尼性能提高明显,综合性能相比其他更佳。     

短切碳纤维对NR/NBR阻尼材料性能的影响

为了探索天然橡胶/丁腈橡胶的阻尼性能,研究了短切碳纤维(CF)对天然橡胶/丁腈橡胶(NR/NBR)阻尼材料硫化特性、力学性能及阻尼性能的影响。结果表明:随着CF添加量增大,共混胶ML、MH和MH-ML增大,ts1缩短而tc90略有延长;拉伸强度和拉断伸长率下降,撕裂强度先增大后减小,当CF为10份时达到最大值,定伸应力明显增大,回弹性下降;滞后能量密度(HED)和阻尼系数增大;DMA测试表明:NR和NBR两相损耗因子(tanδ)峰值均略有下降,损耗模量E'显著增大,室温及较高温度下的tanδ随CF添加量增大而逐渐增大。可以看出,CF的加入能有效增强NR/NBR共混胶的阻尼性能。     

有机蒙脱土对NR/NBR阻尼材料性能的影响

研究了有机蒙脱土(OMMT)对天然橡胶/丁腈橡胶(NR/NBR)阻尼材料硫化特性、力学性能及阻尼性能的影响。结果表明:随着OMMT添加量增大,共混胶M_L、M_H和M_H-M_L增大,t_(s1)和t_(c90)逐渐缩短;拉伸强度、撕裂强度先增大后减小,OMMT为4份时最佳,拉断伸长率降低,定伸应力和硬度增大,回弹性下降;滞后能量密度(HED)和阻尼系数增大。DMA测试表明,NR相损耗峰值略有减小,而NBR相损耗峰值逐渐增大,两相损耗模量E"先增大后减小,在OMMT为4份最大。     

天然鳞片石墨对天然橡胶/丁腈橡胶阻尼材料性能的影响

研究天然鳞片石墨(FG)对天然橡胶(NR)/丁腈橡胶(NBR)并用胶阻尼材料性能的影响。结果表明:随着FG用量增大,NR/NBR并用胶的交联密度提高,硫化速率降低;硬度和定伸应力提高,拉伸强度和撕裂强度先提高后降低,当FG用量为10份时拉伸强度和撕裂强度最高;拉伸/压缩-恢复过程中的滞后能量密度和阻尼系数增大,NR相的损耗因子(tanδ)最大值增大,NBR相的tanδ最大值减小,两相的损耗模量均增大,阻尼性能明显提高。     

橡胶合金SG-301对天然橡胶/丁腈橡胶阻尼材料性能的影响

考察了橡胶合金SG-301对天然橡胶(NR)/丁腈橡胶(NBR)共混胶硫化特性、物理机械性能、压缩生热以及阻尼性能的影响。结果表明,随着SG-301用量的增加,NR/NBR共混胶的最小转矩、最大转矩及转矩差值均逐渐增大,焦烧时间和正硫化时间基本没有变化,拉伸强度、撕裂强度和扯断伸长率均先增大后减小,当SG-301用量为5份时达到最大值,同时,100%定伸应力、300%定伸应力、邵尔A硬度、压缩永久变形和疲劳温升均逐渐增大,回弹性逐渐下降,且两相的损耗峰逐渐靠近,损耗因子峰值均逐渐减小,损耗模量逐渐增大,室温以上温度时的损耗因子逐渐增大。     

硫化体系对NR/NBR阻尼材料性能的影响

研究了硫化体系对天然橡胶/丁腈橡胶(NR/NBR)阻尼材料硫化特性、力学性能、压缩生热以及阻尼性能的影响。结果表明,随着硫磺用量减小而促进剂用量增大,共混胶M_L、M_H和M_H-M_L均减小,t_(s1)缩短而t_(c90)先缩短后延长;共混胶拉伸强度、拉断伸长率、定伸应力、撕裂强度和硬度均逐渐减小,回弹性下降;温升增大而压缩永久变形逐渐减小;滞后能量密度(HED)和阻尼系数增大。DMA表明,NR和NBR两个损耗因子峰略有向低温位移的趋势,且峰值tanδmax明显增大,损耗模量也有所增大,反映出共混胶阻尼性能的提升。     

多壁碳纳米管对天然橡胶/丁腈橡胶阻尼材料性能的影响

研究了多壁碳纳米管(MWCNT)的用量对天然橡胶(NR)/丁腈橡胶(NBR)共混胶的硫化特性、力学性能及阻尼性能的影响。结果表明,随着MWCNT用量的增加,NR/NBR共混胶的最小转矩、最大转矩、最大转矩与最小转矩之差均增大,焦烧时间和正硫化时间缩短;扯断伸长率逐渐减小,撕裂强度、定伸应力和邵尔A硬度逐渐增大,回弹性下降,拉伸强度先增大后减小,当MWCNT用量为4.0份时拉伸强度达到最大值。拉伸/压缩-恢复过程中的滞后能量密度和阻尼系数增大。     

环氧化天然橡胶对天然橡胶/丁腈橡胶阻尼材料性能的影响

研究环氧化天然橡胶(ENR-40)对天然橡胶(NR)/丁腈橡胶(NBR)阻尼材料综合性能的影响。结果表明:随着ENR-40用量的增大,并用胶的最大转矩、最小转矩及两者之差增大,焦烧时间和正硫化时间略延长;拉伸强度和拉断伸长率先增大后略有减小,撕裂强度和定伸应力逐渐增大,硬度不变,回弹值略有减小;压缩永久变形和疲劳温升逐渐减小,滞后能量密度和阻尼系数增大;DMA测试结果显示,两相损耗峰靠近,NR的损耗因子峰值和损耗模量减小,NBR的损耗因子峰值和损耗模量增大。     

酚醛树脂用量对天然橡胶/丁腈橡胶阻尼材料性能的影响

研究了增黏型酚醛树脂(PF)用量对天然橡胶/丁腈橡胶共混阻尼材料的硫化特性、力学性能、压缩生热以及阻尼性能的影响。结果表明,随着PF用量由0增加至10份(质量),天然橡胶/丁腈橡胶共混胶的最小和最大转矩及转矩差均减小,焦烧时间和正硫化时间延长;拉伸强度和定伸应力减小,扯断伸长率和撕裂强度增大,回弹性显著下降;疲劳温升和动态压缩永久变形增大;滞后能量密度和阻尼系数逐渐增大。动态力学分析结果表明,共混后两相的损耗因子峰值均略有下降,但两相的玻璃化转变区域都明显向高温方向移动,共混胶损耗模量峰也向高温方向移动且峰值略有增大,室温附近的阻尼性能明显增强。     

反式聚辛烯橡胶对天然橡胶性能的影响

研究了反式聚辛烯橡胶(TOR)对天然橡胶(NR)动态力学性能、力学性能和屈挠疲劳性能的影响。结果表明,在-70℃~60℃范围内,随着TOR用量的逐渐增大,NR/TOR共混胶损耗因子峰值和Tg均呈现逐渐降低的趋势;在-30℃~60℃范围内,NR/TOR共混胶损耗因子曲线上均出现TOR结晶熔融峰;NR/TOR共混胶损耗因子值均低于NR纯胶;共混胶硬度、无割口直角撕裂强度和回弹性均逐渐升高,拉伸强度先增大后减小,拉断伸长率和相对体积磨耗量均逐渐降低,压缩永久变形降低后趋于稳定,屈挠疲劳性能逐渐升高;当TOR用量达到20份时,共混胶屈挠疲劳性能又出现下降趋势。     

凝固方法对天然橡胶力学性能的影响

研究了三种不同凝固方法对天然橡胶性能和炭黑/天然橡胶硫化胶力学性能的影响。结果表明,采用十二烷基硫酸钠和氯化钙凝固制得的天然橡胶达到5号标准橡胶的质量,其力学性能比用醋酸凝固所制得的天然橡胶的力学性能要好。     

低溴化天然橡胶的研究

对自制的低溴化天然橡胶(BNR)的溴含量、红外谱图、在甲苯中溶解性能、不饱和度及综合力学性能进行研究分析。结果表明:随着反应过程中溴化液用量的增加,制得的低溴BNR的溴含量也增大,且溴含量不与溴化液用量成线性正比关系;溴化天然胶乳的红外光谱分析表明,溴已经接到天然橡胶分子链上,其C-Br键对应的红外光谱位置分别为956 cm-19、08 cm-1;在常温下,低溴BNR在甲苯中溶解性较差,在水浴加热70℃情况下,对低溴BNR在甲苯中的溶解性略有改善,同时随溴含量的增加,溶解性也越差。经塑炼后的低溴BNR在水浴加热70℃的情况下,对低溴BNR能完全溶于甲苯溶剂中;制得的低溴BNR的不饱和度略有降低,不饱和度随溴化液用量的增加变化不大;低溴BNR的加工性能总体较好,经溴化后的天然橡胶较纯胶的综合力学性能都有所下降,其中当硫磺用量为2.7份时,综合力学性能相对较好。     

Cure characteristics and mechanical properties of hydrogenated natural rubber/natural rubber blends

The cure characteristics and mechanical properties of blends consisting of hydrogenated natural rubber (HNR) and natural rubber (NR) blends were investigated. The HNR/NR blends at 50/50 wt ratio were vulcanized using various cure systems: peroxide vulcanization, conventional vulcanization with peroxide, and efficient vulcanization with peroxide. The HNR/NR vulcanizates cured by the combination of peroxide and sulfur donor (tetramethylthiuram disulfide, TMTD) in the efficient vulcanization with peroxide exhibited the best mechanical properties. It was also found that the hydrogenation level of HNR did not affect the tensile strength of the vulcanizates. The tensile strength of the blends decreased with increasing HNR content because of the higher incompatibility to cause the noncoherency behavior between NR and HNR. However, the HNR/NR vulcanizate at 50/50 wt ratio showed the maximum ultimate elongation corresponding to a co‐continuous morphology as attested to by scanning electron micrographs. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

环氧化天然橡胶贮存性能的变异

对环氧化天然橡胶 (ENR)及其胶乳 (ENRL)进行了为期 2年的贮存试验 ,考察其外观和主要物理性能的变异状况 ,探讨了这些性状变异的机理 ,了解到ENR和ENRL原材料长期贮存 ,其外观无明显变化。     

The behavior of dithiocarbimate derivative as safety accelerator of natural rubber compounds

A conventional vulcanization system containing tetrabutylammonium bis(4‐methylphenyldithiocarbimato)zincate(II) (ZNIBU) was used for curing of natural rubber (NR) compounds. Rheometric (t_s1, t₉₀, and CRI) and mechanical properties, such as tensile and tear strengths and modulus at 300%, were measured to evaluate the acceleration potential of ZNIBU. Commercial accelerators (TMTD, MBTS, and CBS) and a binary system CBS/ZNIBU were also tested for comparison purposes. It was observed that ZNIBU alone does not give either safe scorch time or cure rates appropriate for industrial applications. Nevertheless, mechanical properties are comparable to those given by the other accelerators used. As for the binary system, positive synergistic effects can be found in tear strength and modulus of NR vulcanizates. Besides, ZNIBU does not contribute for the formation of nitrosamines in the vulcanization process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

The effects of natural astaxanthin-modified silica on properties of natural rubber

Natural astaxanthin is a natural substance extracted from algae such as Haematococcus pluvialis. Its molecular structure contains conjugated double bonds as well as keto and hydroxyl groups, and therefore it has high activity. In this research, natural astaxanthin was used to modify the surface of the silica, and its effects on natural rubber vulcanization properties, physical and mechanical properties, dynamic properties, and antiaging properties were studied by means of rubber process analyzer, dynamic mechanical anaylsis, and scanning electron microscopy. The results showed that natural astaxanthin-modified silica could reduce the degree of delayed vulcanization. At the same time, the resilience and abrasion resistance of the obtained vulcanizates were increased. The DIN abrasion volume of the vulcanizates modified and reinforced by the second strategy decreased by 19.2% and 23.6%, respectively; the Payne effect of the natural astaxanthin-modified silica/NR composites was weakened, and the dispersibility of the filler and the compatibility with the rubber matrix was significantly improved. Regardless of which strategy was used to modify the silica, the vulcanizates had a lower rolling resistance. Specially, it could greatly improve the hot air aging resistance property of rubber. Natural astaxanthin as being a renewable feedstock is expected to have a quite broad applications in the rubber industry. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 136, 47287.     

淀粉纳米晶对天然胶乳性能的影响

将淀粉纳米晶作为天然胶乳的补强剂,研究其对天然胶乳的胶体性能及硫化胶膜的物机性能、耐水性和耐溶剂的影响。研究结果表明:将淀粉纳米晶加入天然胶乳后,胶乳的粘度变化不大,机械稳定度提高;硫化胶膜的物机性能明显提高,耐溶剂性提高,而耐水性降低。     

三氯溴甲烷改性天然胶乳的研究

用三氯溴甲烷改性天然胶乳，研究了反应时间、反应温度、三氯溴甲烷的用量等对改性胶乳的硫化胶膜物理机械性能的影响，利用DSC对产物进行了分析。结果表明，反应时间为10h，反应温度在35℃时，所得胶膜物理机械性能较好；随着三氯溴甲烷用量的增加，改性天然胶乳的硫化胶膜物理机械性能下降：三氯溴甲烷改性天然胶乳的玻璃化温度高于未改性天然胶乳。     

Comparison of physical and mechanical properties of NR/carbon black/reclaimed rubber blends vulcanized by conventional thermal and microwave irradiation methods

This work experimentally monitored the physical and mechanical properties of natural rubber/carbon black/reclaimed rubber blends vulcanized by microwave (MW) irradiation and conventional thermal (CT) systems, and the curing mechanisms are addressed in conjunction with the vulcanizate properties. The microwave oven for rubber blend vulcanization was specially designed and constructed in this work. The results suggested that the tensile modulus and the hardness of the vulcanizates could be enhanced by increasing the reclaimed rubber (RR) content, whereas the tensile stress, elongation at break, and tear strength decreased with the RR loading. The mechanical properties of the vulcanizates from the CT method were higher than those from the MW method. The vulcanizates from the MW method had higher resistance to toluene penetration than those from the CT method. The differences in the properties of the vulcanizates from the CT and MW methods became smaller at higher RR contents. The sensitivity in property changes of the vulcanizates due to addition of the RR content was greater for the CT method than for the MW method. The differences in the results between these two curing systems could be explained in terms of the density and the types of crosslinks present in the vulcanizates. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 5039–5048, 2006     

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。