二苄基二硫代氨基甲酸锌的合成及应用研究

通过研究金属氧化物与其他原料在水中的"一步法"合成工艺,制备了橡胶硫化促进剂二苄基二硫代氨基甲酸锌,收率达到87%。并与传统促进剂作比较,研究了该促进剂对NR力学性能和硫化性能的影响。结果表明,二苄基二硫代氨基甲酸锌是一种性能优良的硫化促进剂,完全可取代传统的二乙基二硫代氨基甲酸锌之类的促进剂。     

促进剂种类对ZnO硫化BIIR的影响

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。     

二硫代氨基甲酸镧双配体稀土促进剂第二配体对三元乙丙橡胶性能的影响

研究二乙基二硫代氨基甲酸-二苯胍-镧(LaDC-D)、二乙基二硫代氨基甲酸-硫脲-镧(LaDC-TU)、二乙基二硫代氨基甲酸-2-巯基苯并咪唑-镧(LaDC-MB)和二乙基二硫代氨基甲酸-2,6-二叔丁基-4-甲基苯酚-镧(LaDC-BHT)4种双配体稀土促进剂对三元乙丙橡胶(EPDM)性能的影响,并与单配体稀土促进剂二乙基二硫代氨基甲酸镧(LaDC)进行对比。结果表明:与LaDC相比,LaDC-D具有较好的硫化促进活性,两种配体发生了较好的协同活化作用,混炼胶的t90明显缩短,硫化胶的交联密度增大;第二配体为具有防老效果的两种双配体稀土促进剂LaDC-MB与LaDC-BHT硫化胶的撕裂强度较高,抗切割性能和耐热氧老化性能较好,其中LaDC-MB硫化胶的耐热氧老化性能最好;双配体稀土促进剂不仅能有效提高混炼胶的硫化效率,而且能改善硫化胶的耐热氧老化性能,为橡胶多功能助剂的开发提供了新思路。     

环保型促进剂ZBEC-70在EPDM汽车密封条胶料中的应用

本文对比研究了环保型促进剂ZBEC-70(二苄基二硫代氨基甲酸锌)替代ZDBC-80、ZDEC-80、ZDMC-80、TDEC-75等二硫代氨基甲酸盐类普通促进剂在EPDM汽车密封条胶料中的应用。结果表明:与普通促进剂ZDBC-80、ZDEC-80、ZDMC-80、TDEC-75对应的胶料相比,ZBEC-70所对应的胶料具有较大的交联密度,物理性能基本相当,耐热老化性能优异,压缩永久变形较小,在高温硫化时不产生致癌性的亚硝胺物质。促进剂ZBEC-70是二硫代氨基甲酸盐类普通促进剂ZDBC-80、ZDEC-80、ZDMC-80、TDEC-75等的理想环保替代品。     

环保型促进剂二苄基二硫代氨基甲酸锌对天然胶乳硫化胶膜性能的影响

选择二苄基二硫代氨基甲酸锌(ZBDC)、二异丙基黄原聚硫、二硫化四苄基秋兰姆作为天然胶乳(NRL)的硫化促进剂,采用正交试验确定了NBL的硫化配方及最佳工艺,对比了促进剂ZBDC及传统促进剂二乙基二硫代氨基甲酸锌(ZDC)对NRL硫化胶膜性能的影响,考察了贮存时间对NRL硫化程度及硫化NRL黏度、机械稳定性的影响。结果表明,硫化NRL的最佳配方及工艺:促进剂ZBDC、硫黄、氧化锌用量分别为0.75,1.25,0.50份,硫化温度为70℃,硫化时间为2.5 h;随着促进剂ZBDC用量的增加,NRL硫化胶膜的交联密度逐渐增大,而300%定伸应力、500%定伸应力、700%定伸应力、拉伸强度均呈现先增大后减小的趋势;当促进剂ZBDC与ZDC并用时,硫化胶膜的300%定伸应力、500%定伸应力、700%定伸应力和交联密度都达到了最大值,但拉伸强度和撕裂强度比采用最优方案制得硫化胶膜小;随着促进剂ZBDC用量的增加,NRL硫化胶膜的耐老化性能先提高后又下降;无论ZDC与ZBDC并用还是单独使用,硫化胶膜的耐老化性能都较优;随着贮存时间的延长,无论是使用环保型促进剂ZBDC还是使用促进剂ZDC,NRL的硫化程度均增加,硫化NRL的黏度均逐渐增大,而机械稳定性先稍有提高后下降。     

防焦剂MTP和CTP在秋兰姆无硫硫化体系中防焦机理的探讨

本文通过试验对防焦剂MTP与CTP在TMTD无硫化体系中的防焦机理作了探讨。防焦剂MPP和CTP均能与TMTD无硫硫化体系中所产生的超促进剂ZDMC——二甲基二硫代氨基甲酸锌反应,从而延迟了ZDMC浓度的积累,延迟了焦烧,所以MTP与CTP在TMTD无硫硫化体系中具有防焦作用。 CTP与ZDMC作用生成二甲基硫代氨基甲醚基吗啉基二硫化物(简称DTMS)和酞酰亚胺锌盐。DTMS是一种延迟性的活性硫化剂,它使橡胶焦烧延迟,硫化速度加快,交联密度提高。 CTP与ZDMC作用生成二甲基硫代氨基甲酰基环己基二硫化物(简称DTCS)和酞酰亚胺锌盐,DTCS不能引起橡胶硫化,因此CTP虽能防止焦烧但因它使硫化剂量受到损失因而使胶料性能下降。     

影响天然胶乳硫化胶膜N-亚硝胺含量若干因素的研究*

目前胶乳工业常用的仲胺基型硫化促进剂(如ZDC、TMTD等)在胶乳制品加工过程中容易产生致癌性N-亚硝胺,其对人体健康产生很大的影响。降低胶乳制品中N-亚硝胺的含量是胶乳制品行业亟需解决的一大问题。本研究采用硫磺硫化体系,考察氢氧化钙Ca(OH)₂、氢氧化钡Ba(OH)₂等碱土金属氢氧化物、抗坏血酸(VC)和α-生育酚(VE)等亚硝胺消除剂、N-亚硝基胺生成量低的硫化促进剂如二苄基二硫代氨基甲酸锌(ZBEC)、二异丁基二硫代氨基甲酸锌(ZDiBC)等对所制备的天然胶乳硫化胶膜的N-亚硝胺含量的影响,同时考察硫化温度、沥滤等加工工艺条件对制备的硫化胶膜N-亚硝胺含量的影响。     

橡胶助剂的发展现状(二)

2．4 Perkacit ZBEC Perkacit ZBEC化学名为二苄基二硫代氨基甲酸锌,为美国Akron公司和尤尼罗伊尔公司新开发的二硫代氨基甲酸盐类促进剂,不易产生致癌亚硝胺,硫化活性温度较低,操作较为安全,是噻唑类促进剂优良的活化剂,可用于替代促进剂ZDMC（二甲基二硫代氨基甲酸锌）、ZDEC（二乙基二硫代氨基甲酸锌）等,用作天然橡胶、丁苯橡胶、丁基橡胶、三元乙丙橡胶、     

促进剂ZBEC对天然胶乳胶膜的硫化及力学性能的影响

研究了二苄基二硫代氨基甲酸锌(ZBEC)、二乙基二硫代氨基甲酸锌(ZDC)以及氧化锌(ZnO)和硫化温度对天然胶乳配合胶膜的硫化及力学性能的影响。结果表明,随着促进剂ZBEC、ZDC、ZnO用量的增加和硫化温度的提高,天然胶乳配合胶膜的硫化速度显著提高,且与ZDC相比,ZBEC略快。当ZBEC用量从0.5份增加到1.5份时,定伸应力、拉伸强度、撕裂强度先增加后减小。当ZDC用量从0.5份增加到1.5份时,定伸应力、拉伸强度随之增大,撕裂强度先增大后减小。随硫化温度的提高,以ZBEC为促进剂的硫化体系及以ZDC为促进剂的硫化体系的硫化胶膜的定伸应力、拉伸强度及撕裂强度均先增大后减小。     

二硫代氨基甲酸锌和噻唑类促进剂并用对天然橡胶的硫化作用

在噻唑类促进剂存在情况下,研究了天然橡胶硫化过程中由安全胺衍生的几种二硫代氨基甲酸锌(ZDCs)生成安全的二硫代氨基甲酸盐。比较了常规的不安全的二甲基二硫代氨基甲酸锌(ZDMC)与结合了噻唑类促进剂的安全的ZDC的力学性能。研究表明,二硫化秋兰姆和2-巯基苯并噻唑(MBT)总是形成于ZDC与二硫化二苯并噻唑(MBTS)或ZDC与N-环己-2-苯并噻唑次磺酰胺(CBS)的反应过程。结果证明,从MTBS或CBS生成的MBT与ZDC反应生成二硫化四甲基秋兰姆。根据硫化和物理数据讨论了此协同活性,并采用高效液相色谱分析结果,对反应机理进行了解释。在研究的所有双组份系统中都观察到了协同活性。当二硫代氨基甲酸锌(N-苄基哌唑)促进系统中的比例为3:6mM时,获得最高的拉伸强度。在拉伸强度和模量值方面,结合噻唑基的安全ZDCs促进剂可以成功替代不安全的ZDMC。     

Dual crosslinking of carboxylated nitrile butadiene rubber latex employing the thiol‐ene photoreaction

At present, the most common used crosslinking process for carboxylated nitrile butadiene rubber (XNBR) latex is an accelerated sulfur curing system with zinc oxide. To avoid allergenic reactions related to residual accelerator levels in dipped XNBR latex articles such as medical gloves, a dual curing process has been developed combining thermal and photochemical crosslinking reactions. The two‐step procedure involves the formation of covalent and ionic bonds to ensure good mechanical properties of the final products. The photochemical thiol‐ene reaction is used to generate covalent crosslinks between the remaining C?C double bonds of the butadiene units whereas the carboxylic moieties are conventionally cured with divalent metal oxides (ZnO) under elevated temperature (formation of ionic crosslinks). The photochemical curing step is carried out both in the latex phase using a falling film photoreactor (prevulcanization) as well as in the solid phase by UV irradiation of dried XNBR films (postvulcanization). The mechanical properties and crosslink densities of the cured XNBR films are determined and the influence of selected curing parameters is assessed. The results give evidence that a combined approach of thermal prevulcanization and photochemical postvulcanization makes the production of latex articles (e.g., gloves) with tailored properties and good skin compatibility feasible. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

氟橡胶双酚AF/BPP硫化体系硫化特性的研究

研究了双酚AF硫化体系中硫化剂双酚AF、促进剂BPP对氟橡胶硫化特性的影响以及硫化温度对硫化特性的影响.结果表明：硫化剂双酚AF的用量主要影响胶料的交联密度以及硫化时间,并且可以改善胶料的加工性能;促进剂BPP的用量主要影响胶料的硫化时间,对加工性能有一定的影响;硫化温度的提高会使交联密度下降.     

快速硫化型丁腈橡胶的特征行为

分别在丁腈橡胶(NBR)中采用湿法和干法填充不同类型的促进剂制得的混炼胶,研究了不同质量分数的促进剂对硫化胶的交联密度、硫化速率和物理性能的影响.结果表明,采用湿法填充0.12％～0.16％(质量分数)二硫化秋兰姆类促进剂可以获得快速、适宜和可控的硫化速率,硫化胶的综合物理性能优良.     

Dramatic influence of curing temperature on micro–nano structure transform of HNBR filled with zinc dimethacrylate

The influence of the curing temperature on micro‐nano structure transform of hydrogenated nitrile‐butadiene rubber (HNBR) reinforced by zinc dimethacrylate (ZDMA) through in situ polymerization was studied by means of Scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, and X‐ray diffraction. The results showed that both the amount and diameter of the poly‐ZDMA aggregates increased and the graft ratio of poly‐ZDMA decreased with the increase of curing temperature. Meanwhile, with the increase of curing temperature, the maximum torque of the curing curve, the crosslinking density (especially for the ionic crosslinking density), and the mechanical properties of HNBR/ZDMA composite decreased significantly. We put forward a possible mechanism that can well explain the phenomenon observed in this work. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Molecular dynamics simulation of crosslinking process and mechanical properties of epoxy under the accelerator

To simulate the crosslinking process of epoxy resin under the accelerator action, the crosslinking system of bisphenol-A diglycidyl ether (DGEBA) as a monomer, methyl tetrahydro-phthalic anhydride (MTHPA) as a thermal curing agent and 2,4,6-tris (dimethylaminomethyl) phenol (DMP-30) as a thermal curing accelerator has been studied using molecular dynamics (MD) simulation. An algorithm that can construct the high-crosslinked system with different crosslinking density is completed based on the Perl language, and the subsequent properties are simulated. The results of molecular dynamics simulation show that modulus have an increasing trend, and glass transition temperature (Tg) raises from 325 K to 480 K when crosslinking density is from 0% to 95.5%. Conversely, cohesive energy density lessens from 620 J/cm³ to 170 J/cm³, solubility and Poisson's ratio decrease, and the tensile strength firstly increases and then diminishes. The friction coefficient decreases firstly and then increases, meanwhile, the temperature suddenly adds by 20 K and the relative concentration distribution (RCD) grows by 1.58 times at the contact surface. This study predicts for the crosslinking process and micro mechanical properties in the DGEBA/MTHPA/DMP-30 system.     

Phthalonitrile end‐capped polyarylene ether nitrile: crystals embedded in matrix through crosslinking reaction

A novel single‐component composite based on phthalonitrile end‐capped polyarylene ether nitrile (PEN‐Ph) which undergoes a crosslinking reaction combined with crystallization behavior has been prepared successfully by hot compressing. The project focuses on studying the influence of the processing temperature and curing time on the crosslinking reaction and crystallization behavior. Differential scanning calorimetry analysis indicates that the crosslinking degree increases with an increase of processing temperature and curing time. In contrast, the crystallinity increases first and then decreases as the curing time increases, owing to the effect of the restriction of the crosslinking reaction on the crystallization behavior. Thermal polarizing microscope images provide direct evidence for crystal formation as a result of crosslinking reaction. Moreover, through comparative analysis of amorphous and crystallized PEN‐Ph sheets, the conclusion is drawn that the glass transition temperature and mechanical properties are affected by not only the degree of crosslinking but also by the crystallinity. © 2015 Society of Chemical Industry     

Synthesis of isocyanurate-based imidazole carboxylate as thermal latent curing accelerator for thermosetting epoxy resins

A novel thermal latent curing accelerator, 1-(2-cyanoethyl)-2-methylimidazole/tris (2-carboxyethyl) isocyanurate adduct (2MICN-T), was successfully synthesized through an acid–base neutralization of tris(2-carboxyethyl)isocyanurate (TCEIC) and 1-(2-cyanoethyl)-2-methylimidazole (2MICN). It was further added into diglycidylether of bisphenol A based epoxy resin/methylhexahydrophthalic anhydride mixture to form one-component curing systems. With the addition of 2 wt% of 2MICN-T, the one-component system could be steadily stored for more than 1 month at room temperature, while the shelf life of 2MICN curing system was only 2 days. Nonisothermal differential scanning calorimeter also demonstrated the excellent thermal latency of 2MICN-T in low-temperature region and rapid initiation of the curing reaction when raising temperature. Compared to the cured resins with original 2MICN as accelerator, the resulted thermosets exhibited enhanced glassy storage modulus, glass transition temperature, and thermal stability when 2 wt% of 2MICN-T was applied. It was attributed to the chemical incorporation of the isocyanurate moieties with multi carboxyl groups and nitrogen-contained heterocyclic ring, effectively increasing the crosslinking density, chain rigidity, and heat resistance of the cured resin. Thus, it is suggested that 2MICN-T can play both roles as latent curing accelerator and modifier for one-component epoxy compounds, and is particularly recommended for application in electronic packaging fields.     

Thermally stable bromobutyl rubber with a high crosslinking density based on a 4,4′‐bismaleimidodiphenylmethane curing agent

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.     

快速固化酚醛树脂胶黏剂的研制

以缩短酚醛树脂固化时间为目的,使用纳米氧化铝为催化剂,丁腈橡胶为增韧剂,AlCl3络合物为固化促进剂,制备了一种能够快速固化的酚醛树脂胶黏剂。通过固化时间、DSC、TG和力学性能等测试,结果表明,当加入15%丁腈橡胶和2%AlCl3络合物时,酚醛树脂胶黏剂的增韧效果和固化速度均为最佳,可在180℃下20min内实现快速固化,同时具有优异的耐热性能和力学性能。     

原位合成甲基丙烯酸锂增强丁腈橡胶的性能和结构

讨论了在过氧化二异丙苯(DCP)的作用下,氢氧化锂和甲基丙烯酸在混炼过程中原位生成的甲基丙烯酸锂(LiMA)增强丁腈橡胶(NBR)的性能和结构。结果表明,原位生成LiMA对NBR有较明显的增强作用,随着LiMA生成量的增加,NBR硫化胶的邵尔A硬度、100%定伸应力和撕裂强度逐渐增加,拉伸强度和扯断伸长率呈现先上升后下降的趋势;在DCP的作用下,LiMA可显著提高NBR的硫化速率及硫化程度,硫化速率与LiMA生成量呈线性增加关系;随着LiMA生成量的增加,NBR硫化胶的总相对交联密度、离子键相对交联密度增加,而共价键相对交联密度有所下降,说明LiMA改变了NBR的结构。