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改性木质素作BIIR交联剂 总被引:1,自引:0,他引:1
研究了羟甲基化木质素(HKL)对BIIR的交联。结果表明,在165℃或以上的温度下,BIIR/HKL混炼胶转矩随硫化时间的延长而上升,这是由于木质素与BIIR形成了交联网状结构所致。10份HKL在165℃交联BIIR达t90所需的时间为650s;当温度升至175℃,达t90的时间则为418s。随羟甲基化木质素质量分数提高,达到t90时间缩短。硫化胶主要物理机械性能同样表明这一体系已形成了三维网状结构。改性木质素在这一体系中,不仅有增强作用,而且可使BIIR橡胶交联。 相似文献
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考察了烯丙基酚醛树脂与传统酚醛树脂(溴化对-特辛基酚醛树脂、辛基酚醛树脂)对溴化丁基橡胶(BIIR)硫化特性、物理机械性能及耐老化性能的影响,并采用差示扫描量热仪和无转子硫化仪研究了3种酚醛树脂硫化BIIR的反应动力学,探讨了硫化机理。结果表明,烯丙基酚醛树脂的加入能提高BIIR混炼胶的硫化速率,缩短正硫化时间,降低硫化反应活化能,提高硫化反应活性;烯丙基酚醛树脂硫化BIIR的物理机械性能优于辛基酚醛树脂硫化BIIR,与溴化对-特辛基酚醛树脂硫化BIIR相当,且耐老化性能最优。 相似文献
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选用无溶剂的本体法,以N-溴代琥珀酰亚胺与少量丁基橡胶(IIR)和稳定剂的预混物为溴化剂,在橡胶加工设备中对IIR进行化学改性,制备溴化丁基橡胶(BIIR)。通过红外光谱、核磁共振氢谱对产物BIIR的结构进行分析,并考察反应时间、温度和溴化剂用量等对BIIR硫化特性和物理性能的影响。结果表明:采用该方法可以制得BIIR,没有观察到腐蚀设备的情况,产物BIIR的硫化速率相比原料IIR有明显提高,硫化特性和物理性能达到了商品BIIR的水平;溴化反应温度应在60~100℃范围内,在所考察的范围内,溴化剂用量和反应时间对BIIR的硫化特性和物理性能影响不大。 相似文献
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研究三氧化二锑/氢氧化铝/十溴二苯乙烷复合阻燃剂对溴化丁基橡胶(BIIR)胶料性能的影响。结果表明:三氧化二锑/氢氧化铝/十溴二苯乙烷的优选配比为30/25/15;随着硫化温度的升高,不同复合阻燃剂用量的BIIR胶料的门尼粘度增大,t90呈缩短趋势,交联程度呈增大趋势;当复合阻燃剂用量为35份、硫化温度为143 ℃时,BIIR胶料的硫化特性、力学性能和耐老化性能较优,阻燃等级达到UL-94V-0,能够较好地满足产品的需求。 相似文献
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研究了不同并用质量比的氯化丁基橡胶/溴化丁基橡胶(CIIR/BIIR)共混胶的硫化特性、力学性能、老化性能和动态力学性能。结果表明,不同并用质量比的CIIR/BIIR共混胶相容性良好,仅有一个损耗因子(tan δ)峰,随着BIIR用量提高,共混胶的交联程度略降低,正硫化时间延长,硫化速率减慢,力学性能没有明显变化,玻璃化转变温度明显向高温偏移;当CIIR/BIIR并用质量比为90/10时,共混胶的动态力学性能达到最优,60℃的tan δ值比纯BIIR硫化胶降低19%。 相似文献
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通过改变促进剂种类,研究了ZnO-促进剂硫化体系对溴化丁基橡胶(BIIR)硫化特性、硫化反应动力学参数及硫化胶物理机械性能的影响。研究表明,促进剂二硫化二苯并噻唑(MBTS)、N-环己基-2-苯并噻唑次磺酰胺(CBS)抑制了ZnO对BIIR的硫化,使硫化胶的交联密度降低,硫化胶的物理机械性能下降;促进剂二硫化四甲基秋兰姆(TMTD)和二甲基二硫代氨基甲酸锌(ZDMC)则促进了ZnO对BIIR的硫化,提高了硫化胶的物理机械性能;MBTS、TMTD、ZDMC均降低了ZnO硫化BIIR的反应活化能。 相似文献
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Thermally stable bromobutyl rubber with a high crosslinking density based on a 4,4′‐bismaleimidodiphenylmethane curing agent
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The development of thermally stable bromobutyl rubbers has been a challenge in rubber chemistry and engineering. In this circumstance, 4,4′‐bismaleimidodiphenylmethane (BMI) was newly applied as a novel crosslinking agent for thermally stable brominated isobutylene–isoprene rubber (BIIR) with a high crosslinking density. With oscillating disk rheometry and differential scanning calorimetry, the curing characteristics of BIIR were systematically investigated with respect to the content of BMI. We found that BMI alone could crosslink BIIR at higher temperature, and a corresponding possible chemical reaction mechanism was proposed. With the introduction of zinc oxide, the curing reaction of BIIR with BMI was significantly accelerated, and the resulting vulcanizate provided a higher state of curing with excellent overcure reversion stability even at a temperature of 190 °C for 2 h. The content of the dicumyl peroxide (DCP) reaction accelerator was also optimized to be BMI/DCP = 1:0.05 on the basis of considerations of the curing rate, scorch safety, maximum rheometric torque, and reversion resistance at 160 °C. Compared with the conventional sulfur‐cured BIIR, the BMI‐cured BIIR exhibited a higher crosslinking density with a superior low compression set property at elevated temperatures and an excellent thermal stability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 44092. 相似文献
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用热失重法(TG)和差示扫描量热法(DSC)分别测定了添加4种新型液体抗氧剂的溴化丁基橡胶(BIIR)的热失重温度、氧化诱导时间和氧化诱导温度,综合考察了4种抗氧剂的热稳定性和抗氧化性能,评选出性能最好的抗氧剂及其最佳添加量,并分别计算了BIIR的等温和非等温(动态)热氧化反应的活化能。结果表明,4种抗氧剂的热稳定性和抗氧化效果差异较大,但均能不同程度改善BIIR热氧化稳定性。等温热氧化动力学实验结果表明,BIIR热氧化反应符合阿伦尼乌斯方程,抗氧剂添加前后BIIR等温氧化反应活化能分别为131.14kJ/mol、150.25kJ/mol;动态热氧化动力学实验得到抗氧剂加入前后BIIR的非等温氧化反应活化能分别为86.23kJ/mol和108.49kJ/mol。 相似文献
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制备了不同交联剂含量的交联聚乙烯(XLPE)材料及滚塑制品,比较了交联母料不同稀释比例下所得材料的流变特性、交联行为,研究了交联剂含量对样品力学性能(弯曲强度、缺口冲击强度)、不同温度时的落锤冲击强度以及厚度梯度方向的晶体尺寸、结晶度以及交联度等微观结构的影响。结果显示:随交联母料稀释比增大,交联反应略有延迟、交联反应程度降低,制品结晶度增加、缺口冲击强度降低、弯曲模量升高;交联母料稀释比在1:6~1:12时,测试温度25℃时样品落锤冲击强度均为25 J/mm以上,测试温度由25℃逐步下降至-40℃时,交联剂含量高的滚塑样品(M1-6)的落锤冲击强度可保持25 J/mm以上,稀释比例较大的滚塑样品出现韧性-脆性转变(-40℃落锤冲击为1 J/mm)。 相似文献
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Pei Xie Kai Wang Peijian Wang Yang Xia Guangsheng Luo 《American Institute of Chemical Engineers》2017,63(3):1002-1009
Bromobutyl rubber (BIIR) is an important synthetic rubber with better vulcanizing behavior than traditional butyl rubber (IIR). It is hard to synthesize for the high reactant viscosity and strong corrosion caused by Br2 and HBr. A microreactor platform was developed to solve the corrosion problem with cheap materials and obtain high quality BIIR based on microscaled mixing. The results showed that low reaction temperature and quickly eliminating HBr from the reacting solution were crucial to obtain high selectivity of demanded molecule structure and prevent polymer from decomposition. Owing to the corrosion resistance ability, a water assistant technology was successfully implemented in the microreactor system, which produced high quality BIIR with almost 100% selectivity and less reduced molecule weight. © 2016 American Institute of Chemical Engineers AIChE J, 63: 1002–1009, 2017 相似文献
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采用动态力学分析(DMA)法和红外光谱(FT-IR)法,研究了不同老化条件下SBSVP(吡啶基官能化苯乙烯-丁二烯-苯乙烯嵌段共聚物)的热老化行为。结果表明:SBSVP在无氧热老化过程中,其降解反应与交联反应并存,并发生动态变化;低于160℃时以降解反应为主,超过160℃时交联反应占优势,聚合物交联密度变化是导致材料储能模量及玻璃化转变温度发生相应变化的主要原因;SBSVP热老化后,其分子链中的C=C键含量降低,说明老化主要发生在PB链段;SBSVP在热老化过程中,老化温度对其影响程度大于老化时间。 相似文献
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Reactive polyimides bearing a vinylcyclopropane (VCP) moiety in the main chain were successfully synthesized from the corresponding diamine with the VCP moiety. Their radical crosslinking using a dithiol proceeded with the radical ring-opening reaction (RROR) of the VCP moiety to afford the corresponding crosslinked polyimides with the CC bonds in crosslinking moieties. Thermal properties of those crosslinked polyimides were evaluated by thermal gravimetry and differential scanning calorimetry. As a result, the increase of the crosslinking degree in the crosslinked polymer exhibited great residual weight at 600°C. In contrast, the tendency of the glass transition temperature was inverse because the increase in the amount of dithiol unit as a crosslinker would enhance the mitigation of the polymer packing structure and activates the mobility of polymer chains. 相似文献