氟橡胶接枝马来酸酐增容氟橡胶/热塑性聚氨酯共混物的性能

研究了氟橡胶(FKM)接枝马来酸酐(FKM-g-MAH)增容FKM/热塑性聚氨酯(TPU)共混物的物理机械性能及动态力学性能.结果表明,当FKM-g-MAH质量分数为15%时,FKM/TPU共混物的物理机械性能最佳;添加增容剂FKM-g-MAH后,FKM/TPU共混物中FKM和TPU两相的相容性得到改善,且其阻尼性能优于纯FKM.     

Dynamic and Thermo-Mechanical Properties of Some Specialty Fluoroelastomers for Low Tg Seal Materials

The viscoelastic behaviour of three different low Tg fluoroelastomer materials belonging to the class of Fluorosilicones (FVMQ), Perfluoropolyether-hydrosilanes (Sifel™) and Perfluoropolyether-polyurethanes (FEU) was investigated. Materials considered were high hardness rubbers and were characterized by dynamic-mechanical analysis (DMA), thermo-mechanical analysis (TMA), and swelling tests in Fuel C and other solvent mixtures. DMA spectra in dynamic scan allowed the determination of Tg and other minor intensity relaxation phenomena. Thermo-mechanical analysis was used to measure the thermal expansion coefficient α _L and the low temperature retraction curve R _e(T) in creep and recovery experiments with different test conditions. Highly diversified behaviours were observed, apparently related to polymer Tg and damping in the rubbery plateau. Swelling measurements showed a better performance for the two perfluoropolyether samples than for fluorosilicones.     

不同填料对246型氟橡胶性能的影响

研究了3种填料（纳米级碳酸钙、空心玻璃微珠、炭黑）对氟橡胶力学性能及加工性能的影响。结果表明，3种填料在氟橡胶基体中因其形态、结构组成、微观分布的不同，在作为填料使用时，各自都表现出自身的特性及优缺点。     

F2311含量对TATB基PBX蠕变性能的影响

以TATB基高聚物粘结炸药(PBX)为原配方,制备了含氟弹性体(F2311)含量分别为0.05%、0.1%、0.2%、0.4%的4种改性配方,采用动态力学分析仪研究了F2311对PBX的三点弯曲蠕变性能影响。结果发现,加入0.4%的F2311使TATB基PBX的抗蠕变性能下降,减少F2311含量有利于提高其抗蠕变性能。含0.05%F2311的改性配方PBX在60℃/6 MPa下的蠕变应变略低于原配方。研究同时采用六元件模型对TATB基PBX及其改性配方的蠕变行为进行模拟。得到了蠕变曲线的本构方程,理论预测模型和试验数据吻合良好。根据时温等效原理,获得了TATB基PBX及其改性配方在参考温度30℃下的蠕变柔量主曲线,结果表明含0.05%F2311的TATB基PBX改性配方的长期抗蠕变性能优于原配方PBX。     

Vulcanization behavior and mechanical properties of organoclay fluoroelastomer nanocomposites

The vulcanization behavior and mechanical properties of clay/fluoroelastomer nanocomposites produced by melt‐mixing of Dyneon FPO 3741 (a terpolymer of vinylidene fluoride, hexafluoropropylene, and tetrafluoroethylene) with 10 phr of unmodified montmorillonite (CloisiteNA) or di(hydrogenated tallow‐alkyl) dimethyl ammonium‐modified montmorillonites (Cloisite15A and Cloisite20A) were studied. The properties of clay/FKM nanocomposites were compared with composites prepared using 10 and 30 phr of carbon black. The effects of clay surfactant and surfactant concentration on the vulcanization behavior, mechanical, and dynamical properties of peroxide cured composites were studied. XRD results of cured composites showed a decrease in d‐spacing and indicated deintercalation of the clays after the vulcanization process. It was also found that organoclays retard the FKM peroxide vulcanization process. Significantly, higher maximum torque on vulcanization was obtained with organoclays versus unmodified clay and carbon black. Although the morphologies of organoclay/FKM nanocomposites studied by XRD and TEM suggest similar intercalated/exfoliated structures, the organoclay with the lowest concentration of surfactant (95 meq/100 g clay) resulted in the highest increase in torque, modulus, hardness, and tear strength in the clay/FKM nanocomposites. It was also found that organoclays can increase both the hydrodynamic reinforcement and hysteresis loss of FKM nanocomposites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

反应型氟橡胶/改性EPDM并用胶的结构与性能

以甲基丙烯酸甲酯和含氟丙烯酸酯为接枝单体制备了改性三元乙丙橡胶(MEPDM)和氟橡胶(FPM)/MEPDM反应型并用胶。利用全反射傅立叶变换红外光谱仪(ATR-FT-IR)、橡胶硫化分析仪(ODR)、动态热机械分析(DMA)和扫描电镜(SEM)等研究了FPM/MEPDM并用胶的结构与性能,同时考察了材料老化前后的力学性能。结果表明,改性单体的接枝率为28.03%,接枝效率为58.54%;并用胶可以实现共硫化,硫化胶界面结合紧密;硫化胶的综合性能随着FPM用量的增大而提高,且老化后力学性能有所改善,含氟官能团向材料表面迁移。     

氟橡胶生产、应用现状与发展趋势

我国汽车工业快速发展促进氟橡胶需求上升。评述氟橡胶生产及应用现状,重点介绍氟橡胶改性和加工技术,并预测了我国氟橡胶工业发展趋势。     

氟橡胶二段硫化挥发物分析

用液上分析器摸拟２６－４１生胶３种不同硫化体系胶料的二段硫化过程，色谱－质谱联用鉴定出大部分挥发物组分。根据硫化反应机理和进一步实验，对结果进行了讨论。     

氟橡胶在碱性环境中脱氟化氢反应机理及其结构

为了研究26型氟橡胶(偏氟乙烯-六氟丙烯二元共聚物)和246型氟橡胶(偏氟乙烯-四氟乙烯-六氟丙烯三元共聚物)在碱性环境中所发生的反应,本文对其反应机理进行了系统的讨论。采用红外(FTIR)、氢谱(1 H-NMR)和氟谱核磁(19 F-NMR)对氟橡胶反应前、后的分子链结构进行了分析,并对不同序列结构双键及羟基含量进行了计算。结果表明,26型和246型氟橡胶在碱性环境中发生脱氟化氢反应时,会伴随着双键重排及氧化反应的发生。其中,26型氟橡胶遵循以Zaitsev规则消除反应为主、Hofmann规则消除反应为辅的脱氟化氢反应,在分子链中5个位置出现了双键;而246型氟橡胶则与之相反,遵循以Hofmann规则消除反应为主、Zaitsev规则消除反应为辅的脱氟化氢反应,在分子链中7个位置出现了双键;两种氟橡胶中遵循Hofmann规则进行消除反应所产生的双键会被氧化为羟基;相同条件下,反应后246型氟橡胶的双键和羟基含量均高于26型氟橡胶。     

Microstructure and properties of fluoroelastomer/butadiene-acrylonitrile rubber interpenetrating polymer networks

Interpenetrating polymer networks （IPNs） based on fluoroelastomer/butadiene-acrylonitrile rubber （FKM/NBR） by molten blending at a high temperature and chemical cross-linking of two components were prepared. The influence of the two networks component on the mechanical properties and thermostabilities was studied. The experimental results show that the mechanical properties of the IPNs are superior to those of the individual FKM and NBR networks due to forming the case of interpenetrating and intercross-linking between the two networks, the mechanical properties and thermal resistance exhibit higher values when 80/20 （w/w） FKM and NBR is blended and respectively cured simultaneously. The co-continuous morphology of the IPNs in the blends of 80/20 （w/w） FKM/NBR is found by transmission electron microscopy （TEM）, the differential scanning calorimetry （DSC） determination shows that the blends of 80/20 （w/w） FKM/NBR have better compatibility, and the glass transition temperature of the elastomer is -21.5 ℃.