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1.
对丁腈橡胶和丁腈酯橡胶的物理机械性能和动态力学性能进行对比研究,讨论了分子结构对材料热氧老化和动态力学性能的影响。结果表明,丁腈橡胶和丁腈酯橡胶物理机械性能相当,热氧老化试验后丁腈酯表现出更优异的力学性能。在动态力学性能试验中,腈基极性强于酯基,侧基极性愈强,其相互间作用力愈大,单键内旋转愈困难,链的柔顺性愈差,同时丁腈酯的酯基具有柔性,可起到增塑剂的作用,综合因素导致丁腈酯橡胶在低温下的动态力学性能优于丁腈橡胶。热氧老化后,丁腈橡胶和丁腈酯橡胶交联度进一步提高,分子链之间的相互作用力变大导致剪切模量增大。丁腈橡胶的损耗因子偏大是由于丁腈橡胶有极性较强的侧腈基,链段运动时内摩擦阻力大内耗高,热氧老化后损耗因子进一步提高。  相似文献   

2.
双烯类液体橡胶的研发进展   总被引:1,自引:0,他引:1  
液体橡胶作为合成橡胶的重要种类,是室温下能流动的橡胶材料。本文介绍了液体橡胶的性能特点及分类,着重阐述了双烯类液体橡胶即液体聚丁二烯橡胶、液体丁腈橡胶、液体异戊橡胶、液体丁苯橡胶和液体氯丁橡胶的结构特征、性能特点及主要用途,并进一步探讨了它们的研发、生产和使用情况。液体橡胶便于实现生产连续化和自动化,且加工方便,顺应时代发展的"低碳"潮流。从产品种类、牌号,应用范围等方面对今后的发展提出了建议。  相似文献   

3.
橡胶拉伸取向和应变诱导结晶被公认为是天然橡胶和一些合成橡胶(如氯丁橡胶、丁基橡胶、氢化丁腈橡胶等)高效自增强的关键所在,研究该现象和行为规律对理解橡胶增强机理具有十分重要的意义.本文总结了常用于研究橡胶拉伸取向和应变诱导结晶的表征方法,对其原理、特点和适用范围进行了对比分析;综述了纳米填料(炭黑,二氧化硅,黏土,碳纳米...  相似文献   

4.
聚氨酯和丁腈橡胶是两种对环氧树脂增韧效果显著的橡胶弹性体,文章分别介绍了这两种弹性体增韧改性环氧树脂的机理和近年来的主要研究进展,并讨论了聚氨酯增韧环氧树脂和丁腈橡胶增韧环氧树脂各自的特点,展望了弹性体增韧环氧树脂的前景。  相似文献   

5.
通过对比研究硫磺固化液体丁腈橡胶、液体丁腈橡胶/苯基缩水甘油醚、液体丁腈橡胶/邻烯丙基苯基缩水甘油醚3个体系的固化反应,推测了硫磺/含双键橡胶/环氧树脂体系的反应机理.采用示差扫描量热(DSC)法、红外光谱(FTIR)法、X射线光电子能谱(XPS)法、动态力学分析(DMA)法研究了固化反应放热,双键和环氧基团随反应时间的变化,固化产物中苯环、氧元素、网络结构与模型化合物结构的关系.实验结果表明,硫磺/液体丁腈橡胶体系是一步反应、硫磺/液体丁腈橡胶/环氧化合物体系是两步反应,且丁腈橡胶与环氧化合物之间有化学键键接;液体丁腈橡胶/硫磺、液体丁腈橡胶/苯基缩水甘油醚/硫磺、液体丁腈橡胶/邻烯丙基苯基缩水甘油醚/硫磺3个体系的玻璃化转变温度依次升高,储能模量、交联密度依次降低.在此基础上提出液体橡胶与环氧化合物的固化反应机理为:硫磺裂解生成硫自由基,一方面部分硫自由基与体系中的双键发生加成反应,另一方面硫自由基与烯丙基α位的活泼氢反应生成巯基,巯基引发环氧基团发生开环反应,体系内的自由基间相互偶合交联.  相似文献   

6.
基于丁腈橡胶中腈基与金属离子的配位作用,设计了一种全新的含可变形微区的橡胶,即金属配位交联丁腈橡胶(NBR)作为可变形微区增强丁苯橡胶.随着可变形微区中配位键含量的提升,橡胶的强度和模量快速提高.引入20 wt%的丁腈橡胶,丁苯橡胶的强度和模量分别提升2.6倍和3.2倍.这一体系的增强机理主要是金属配位交联NBR作为强但可变形微区,一方面模量更高的微区由于流体力学效应,使得橡胶整体模量提高;另一方面,在外力作用下,应力通过强的界面相互作用传递到微区,致使其在样品断裂之前发生强迫高弹形变,耗散机械能,从而显著增强橡胶.微区中强迫高弹形变可通过高温松弛回复,从而恢复力学性能.本工作为通过可变形微区的设计实现非极性橡胶的增强提供了一种新途径.  相似文献   

7.
壳-核结构增韧剂超高增韧非晶共聚酯的形貌和形态   总被引:10,自引:3,他引:7  
研究了马来酸酐接枝的壳核结构增韧剂 (TPEg)对非晶热塑共聚酯 (PETG)的增韧和增强效果 ,并与马来酸酐接枝的纯橡胶类增韧剂 (POEg)作了对比 .TPEg对PETG具有显著的增韧效果 ,当TPEg含量由 5%增加到 1 0 %时 ,共混物就可以发生由脆性到超高韧性的快速转变 .而POEg虽然也可以使PETG发生由脆性到韧性的快速转变 ,但转变是在较高的增韧剂含量下发生的 ,这意味着共混物的抗张强度和模量损失更多 .利用扫描电镜观察、分析了随增韧剂含量的增加 ,共混物的形貌、形态的演化过程 .共混物的缺口冲击韧性与其形貌、形态之间存在很好的对应关系 .  相似文献   

8.
在丁腈橡胶中引入无机金属盐粒子,通过腈基与金属离子之间的固相配位反应来实现丁腈橡胶的配位硫化,创建了一个完全不同于传统硫磺硫化体系的新型非共价键配位交联的橡胶网络体系.同时制备了具有优异的力学性能的配位硫化橡胶材料,既可以作柔性的橡胶材料使用,也可以作为韧性、脆性的塑料材料使用.本文就影响配位交联反应的两个关键因素(金属盐粉末的粒径和丁腈橡胶的丙烯腈含量)进行了探讨,提出了提高配位硫化效率的办法(结晶水、增塑剂等).  相似文献   

9.
聚醚增韧环氧树脂的研究   总被引:1,自引:0,他引:1  
通过端羟基聚四氢呋喃和顺丁烯二酸酐的反应制备了端羧基聚醚。用浊度测定、动态力学实验和扫描电镜观察等方法研究了聚醚增韧环氧树脂的结构形态。聚醚的分子量、端羧基含量以及固化条件对聚醚相颗粒尺寸有很大的影响。这些因素又进一步影响固化产物的力学性能。端羧基聚四氢呋喃作为环氧树脂的增韧剂有两个优点:(1)橡胶相的玻璃化温度低;(2)环氧树脂的耐热性不因添加增韧剂而降低。  相似文献   

10.
(一)丙烯腈是在上世纪未叶首次由莫列尤(Moureu)制得的。丙烯腈的第一个工业产品则是在本世纪三十年代德国生产的“布纳”(Buna N)橡胶,由丁二烯与丙烯腈共聚合制成的一种耐油的丁腈橡胶。以后美国也生产了商品牌号为 GR-A 的丁腈橡胶。在第二次世界大战期间,由于飞机制造工业上广泛地使用丁腈橡胶,因而丙烯腈的生产量突增。而战后其生产量曾一度骤减,1950年后美国牡邦公司(Du Pont Co.)研究出制造人造羊毛的“(?)纶”(Orlon)聚丙烯腈纤维后,丙烯腈的产量回升,特别是随着生产技术的改进和改进纤维的染色等问题后,丙烯腈的产量逐年上升。1954年德意志联邦共和国也生产了以 PAN 为牌号的聚丙烯腈纤维。此后,英国生产了“阿克利兰”(Acrilan)纤  相似文献   

11.
Fullerenol polyurethane (C60‐PU) and linear polyurethane (linear‐PU) modified phenolic resins were prepared in this study. Phenolic resin/C60‐PU and phenolic resin/linear‐PU blends show good miscibility as a result of the intermolecular hydrogen bonding existing between phenolic resin and PU modifiers. DSC and thermogravimetric analysis methods were used to study the thermal properties of phenolic resin blended with different types of PUs. The intermolecular hydrogen bonding that existed between phenolic resin and C60‐PU was investigated by Fourier transform infrared spectroscopy. The morphology and mechanical properties of phenolic resin/C60‐PU and phenolic resin/linear‐PU blends were also investigated. The char yield of the modified phenolic resins decreased with increasing PU modifier content. Significant improvement in the toughness of the modified phenolic resins was observed. The improvements of impact strength were 27.4% for the phenolic resin/linear‐PU system and 54.3% for the phenolic resin/C60‐PU system, respectively, both with 3 phr linear‐PU and C60‐PU content. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 2436–2443, 2001  相似文献   

12.
A novel epoxidized soybean oil (ESO) internally toughened phenolic resin(ESO-IT-PR) with both good toughness and excellent thermal stability was prepared as the matrix resin of copper clad laminate (CCL). FTIR was adopted to investigate the molecular structure of modified phenolic resins and SEM was used to observe the micro morphology of their impacted intersections. The properties of CCLs prepared with these modified phenolic resins were studied to determine the optimal process and investigate the toughening mechanism. The main modifying mechanism is the etherification reaction between phenol hydroxyl and ESO catalyzed by triethanolamine and the chain extension polymerization between ESO and multi-amine gives the long-chain ESO epoxy grafting on the phenolic resin prepolymer. when the ESO content is 30% and the curing agent content is 7%, the ESO toughened phenolic resin possesses optimal performance. The flexible ESO epoxy shows significant toughening effect and it crosslinks with the phenolic resin to form an internally toughened network, which is the key factor for improving the solderleaching resistance of CCL prepared with this modified phenolic resin. __________ Translated from Journal of South China University of Technology (Natural Science Edition), 2007, 35(7): 99–104 [译自: 华南理工大学学报(自然科学版)]  相似文献   

13.
Polymer/layered silicate nanocomposites belong to one of the most promising group of materials of the past few decades and most probably for the near future. Following the pioneering works of Toyota Research Group in the 1980s, the interest on these materials increased rapidly and research is now being carried out world wide, using all kinds of polymers as base material.In this present study, the aim was to investigate the effects of several different production parameters; on the morphology of resol type phenol formaldehyde based layered silicate nanocomposites produced by mixing and casting. For this purpose; two different liquid resol type phenolic resins (PF76 and PF76TD), two different curing methods (heat cure route and acid cure route), two different montmorillonite clays (unmodified Cloisite Na+ and modified Rheospan), two different clay sources (Wyoming-USA and Tokat-Turkey), and five different clay amounts (0.5%, 1%, 1.5%, 3%, 10%) were used.XRD, SEM, TEM analyses and mechanical tests indicated that resol type phenolic resins lead to better structures when they were modified with ethylene glycol and cured by the use of an acidic curing agent. It was also observed that use of modified clay with no more than 1.5 wt% in the phenolic matrix lead to certain degree of exfoliation consequently better structure and higher mechanical performance.  相似文献   

14.
张孝阿 《高分子科学》2015,33(11):1606-1617
Two carborane-containing resol phenolic resins(P1 and P2) with high boron content were synthesized via the reaction of carborane bisphenols(1 and 2) with formaldehyde in the presence of alkaline. HRMS results indicate that P1 is mainly composed of hydroxymethylated o-carborane bisphenols, the Mw of which was restrained around 500 due to the strong steric hindrance of o-carborane bisphenol. In contrast, the molecular weight of P2 was well regulated under various reaction conditions. The obtained resins were characterized with spectroscopic techniques including FTIR, 1H-NMR, 13C-NMR, and 11B-NMR, which gave satisfactory results. TGA studies show that P2 shows char yield of 88.9% and 92.9% at 900 ?C under nitrogen and air respectively. The imported carborane cage endows phenolic resin with ultrahigh char yield. Particularly, the char yield of the obtained carborane-containing phenolic resin under air is higher than that under nitrogen. FTIR and XRD confirm that the carborane cage could react with oxygen to form B2O3 at elevated temperatures, which postpones the thermal decomposition of phenolic resin and accounts for the high char yield.  相似文献   

15.
磁性功能化酚醛树脂的合成及对金属离子的吸附性能   总被引:3,自引:0,他引:3  
刘春萍  关若飞  王妮 《应用化学》2006,23(9):1037-0
磁性功能化酚醛树脂的合成及对金属离子的吸附性能;环氧酚醛树脂;螯合;金属离子;溶胀;吸附容量;吸附动力学  相似文献   

16.
Novel propargyl that contains phenolic resins via azo‐coupling reaction was synthesized. Peculiarities of curing process were investigated by differential scanning calorimetry analysis. Polymerization of resins with azo groups was estimated to be affected by radicals obtained at resin decomposition causing 10°C peak shift to lower temperatures in comparison with resin containing only propargyl group. At the same time, polymerization of triple propargyl bond was shown to not proceed at radical initiation until Cleisen rearrangement and chromene formation. Thermogravimetric analysis revealed increase of thermal stability by 170–190°C and char yield by up to 20% for modified resins in comparison with original novolac resin. Heat deflection temperature estimated by dynamic mechanical analysis was also shown to be increased by at least 110°C for modified resins in comparison with novolac resin. All the synthesized resins are soluble in acetone and used for preparation of unidirectional glass fiber‐based composites. Flexural strength and modulus for modified resins‐based composites were shown to increase by at least 25% and 10% correspondingly in comparison with novolac‐based composite. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

17.
通过酚醛树脂羟基活性基团与6-氯-5,12-萘并萘醌(1)接枝反应,制备了3种有光致变色性的酚醛树脂:萘并萘醌酚醛树脂(2),甲基萘并萘醌酚醛树脂(3)和氯代萘并萘醌酚醛树脂(4).在四氢呋喃(THF)溶液中,3种光致变色聚合物有与6-苯氧基-5,12-萘并萘醌相似的光致变色行为.同时,发现聚合物骨架上的取代基对聚合物的变色速度影响较小,聚合物的平均分子量影响聚合物的变色速度.  相似文献   

18.
利用自制的有机蒙脱土 ,采用浇模固化成型法制备酚醛树脂 /六次甲基四胺 /蒙脱土纳米复合材料 ,并用XRD观察有机蒙脱土分别在热塑性和热固性酚醛树脂中复合行为 .研究发现 ,由于两种树脂的固化反应机理不同 ,热固性酚醛树脂与蒙脱土复合 ,可得插层型纳米复合材料 ;而采用热塑性酚醛树脂进行固化 ,则得到部分剥离的纳米复合材料 .通过DSC进一步研究热塑性酚醛树脂 /蒙脱土复合体系的固化反应动力学 .运用Kissinger ,Flynn Wall Ozawa ,Crane方法求出活化能和反应级数等动力学参数 .结果发现 ,加入蒙脱土使固化反应活化能下降 ,反应级数减小 ,从而有利于固化工艺的实现 ,便于纳米复合材料实际应用 .  相似文献   

19.
摩阻材料用亚麻油改性酚醛树脂的制备及耐热性研究   总被引:1,自引:0,他引:1  
利用亚麻油改性酚醛树脂,得到高性能的摩阻材料用树脂基体.推导了改性机理和结构特征,并进行了耐热试验和分析.结果表明,亚麻油参与了反应并成为聚合物的一部分,亚麻油改性酚醛树脂固化后的结构特征是互穿聚合物网络(IPN),与普通酚醛树脂相比,亚麻油改性酚醛树脂的耐热性能显著提高,可望用作耐高温磨阻材料树脂基体.  相似文献   

20.
Bisphenol A dicyanate ester (BADCy) was modified with different amounts of an engineering thermoplastic, polysulfone (PS) to improve impact strength of the parent resin. Differential scanning calorimetry of the blends suggested that addition of PS widens the curing exotherm of the BADCy considerably. FTIR of cured neat resins indicated total conversion of cyanate functional groups into triazine rings by cyclotrimerization. The cured neat resins showed phase separated morphology with cyanate ester as the continuous phase. The modified resins were shown to have better thermal, hygrothermal and impact strength properties. However, when glass fiber reinforced composites were made using partially polymerized BADCy and PS, very little or no phase separation in the resin was noticed. Flexural and impact strength measurement of composites showed that PS modification has compromised the flexural properties and only retained the impact strength of the parent resin containing composite. This study thus suggests that improvements realized in thermoplastic modification of monomeric BADCy are not directly transferable to composites using a partially prepolymerized BADCy.  相似文献   

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