带烯键含芴聚芳醚酮增韧改性双马来酰亚胺树脂

采用无溶剂自相溶工艺,将侧链带有烯键的含芴聚芳醚酮(RPFEK)溶解于二烯丙基双酚A（DABPA）,低温下加入4,4′-二氨基二苯甲烷双马来酰亚胺(BMDM)进行熔融共聚,再用高温固化的方式制备了带烯键含芴聚芳醚酮增韧的改性双马来酰亚胺（BMDM/DABPA）复合材料。结果表明,这种复合材料是一种互穿交联网络结构,RPFEK的引入不但对复合材料的玻璃化转变温度无明显影响,而且有利于复合材料热稳定性的提高;可反应烯键的引入提高了RPFEK与BMDM树脂的相容性与界面的粘接作用;与纯BMDM/DABPA树脂相比,10 % RPFEK增韧的BMDM/DABPA树脂的冲击强度从9.0 kJ/m2提高到了15.2 kJ/m2。     

烯丙基双酚A改性双马来酰亚胺-三嗪树脂的热性能

以4,4′-二苯甲烷双马来酰亚胺、双酚A型氰酸酯和2,2-二烯丙基双酚A为基本原料制备了改性双马来酰亚胺-三嗪（BT）树脂。系统地研究了2,2-二烯丙基双酚A对BT树脂固化动力学、BT树脂的溶解性能和BT树脂固化物的热性能的影响。研究结果表明：烯丙基双酚A有效地降低了BT树脂的固化反应温度并提高了BT树脂的溶解性能。当烯丙基双酚A的加入量为20%（质量分数）时,BT树脂的固化反应峰值降至233.1 ℃;并且,其固化物的玻璃化转变温度仍然达到239.4 ℃,5%热失重温度为372.9 ℃,显示了良好的耐热性能。     

一种改性双马来酰亚胺共聚树脂体系及其粘接性能的研究

以二苯甲烷双马来酰亚胺和二烯丙基双酚A为共聚单体，在适当的催化剂等作用下，制备了一种改性双马来酰亚胺共聚树脂。本文对这种改性的双马来酰亚胺共聚树脂的溶解性能、固化反应动力学和固化机理进行了讨论；对体系固化物的机电热性能及其胶粘剂的高低温粘接性能也进行了研究。     

双酚芴、双酚A型聚碳酸酯共聚物的合成及其耐热性能研究

本文采用较少摩尔比双酚芴{9,9-二[4-(2-羟乙氧基)苯基]芴,BPHF}与双酚A(BPA)共聚,通过熔融酯交换法制备共聚PC。结果表明,1H NMR表征结果显示产物为共聚物且共聚PC中含有双酚芴链节,DSC表征结果显示,随着BPHF含量的增加,所得共聚PC的Tg与HDT均呈上升趋势,并且产物有且只有一个Tg。此外,考察加入双酚芴进行共聚对聚碳酸酯光学性能(透光率、雾度)的影响,结果表明随着BPHF与BPA的摩尔比在0%～6%的范围内,其光学性能并无显著变化。     

国内文献摘要

正双酚A合成催化剂及其制备方法本发明涉及离子交换树脂法合成双酚A的催化剂及其制备方法。其以苯乙烯或取代苯乙烯为单体,二乙烯基苯基甲烷等为交联剂,合成交联比较均匀的共聚体,共聚体磺化、耐温性改性后用作制备双酚A催化剂基础树脂,按照常规技术以巯基烷基胺为巯基化剂,通过部分中和法对基础树脂进行改性,获得双酚A合成催化剂。本发明在交联聚苯乙烯型     

新型有机硅化环氧树脂

<正>为了克服环氧树脂的某些缺点,北京化工大学以4,4'-二烯丙基双酚A和环氧氯丙烷为原料,采用两步法合成出一种含烯丙基的环氧树脂二烯丙基双酚A二缩水甘油醚(DADGEBA);然后将DADGEBA和三甲氧基硅烷在氯铂酸催化作用下进     

热致液晶聚合物(TLCP)的溶解性研究

以对羟基苯甲酸(HBA)、联苯二酚(BP)、9,9-二(4-羟基苯基)芴(双酚芴BHPF)、对苯二甲酸(TA)和间苯二甲酸(IA)为单体,醋酸酐为酰化试剂,乙酸镁为催化剂,在程序升温条件下合成了两种热致性液晶聚合物,并采用固相聚合工艺对预聚物进行增黏处理,通过红外(FTIR)、热失重分析(TG)、差示扫描量热分析(DSC)、超景深三维显微镜(偏光模式)、扫描电镜(SEM)、毛细管溶液黏度、熔融剪切黏度、色度测试、溶解性实验以及力学性能测试进行了表征分析。结果发现,以具有大侧基的非平面双酚芴结构部分替代线性联苯二酚结构合成的TLCP溶解性提高,说明通过大侧基和非平面的结构引入能够在一定程度上提高液晶聚合物的溶解性能,但由于分子链中线性棒状结构的减少,其液晶性能有所下降。     

高折射率TiO2纳米杂化材料的制备与性能研究

以 1,2-乙二硫醇、四溴双酚 A环氧树脂和 9,9-二（[2,3-环氧丙氧基）苯基 ]芴为原料,LiOH的甲醇溶液为催化剂,采用巯基 -环氧点击化学反应制备含 S和 Br元素的聚合物基体;以钛酸四丁酯为前驱体,采用溶胶 -凝胶法和分段热固化制备出透明高折射率 TiO₂纳米杂化材料。通过红外光谱、纳米粒度仪、椭圆偏振光谱仪、透射电子显微镜和紫外 -可见分光光度计等仪器对其结构、性能进行表征。结果表明： TiO₂粒子在聚合物基体中成功合成并以纳米尺度均匀分散,材料在可见光区域有很高的透光率,大多在 95%左右;随着 TiO₂粒子杂化量的增加,在 486 nm处的折射率由 1.660 2提高到了 1.756 5,阿贝数由 21.65提高到 34.63。     

高折射率TiO_2纳米杂化材料的制备及性能研究

以1,2-乙二硫醇、四溴双酚A环氧树脂和9,9-二[(2,3-环氧丙氧基)苯基]芴为原料,LiOH的甲醇溶液为催化剂,采用巯基-环氧点击化学反应制备含S和Br元素的聚合物基体;以钛酸四丁酯为前驱体,采用溶胶-凝胶法和分段热固化制备出透明高折射率TiO_2纳米杂化材料。通过红外光谱、纳米粒度仪、椭圆偏振光谱仪、透射电子显微镜和紫外-可见分光光度计等仪器对其结构、性能进行表征。结果表明:TiO_2粒子在聚合物基体中成功合成并以纳米尺度均匀分散,材料在可见光区域有很高的透光率,大多在95%左右;随着TiO2粒子杂化量的增加,在486 nm处的折射率由1.660 2提高到了1.756 5,阿贝数由21.65提高到34.63。     

双酚A工业制法技术经济探讨

一、概述双酚A,又称二酚基丙烷,是一种多用途的化工基础原料,在高分子合成工业中占有重要地位。它与其他原料配合可制造环氧树脂、酚醛树脂、不饱和聚酯和乙烯酯等热固性聚合物,也可生产聚碳酸脂、聚砜、苯氧(Phenoxy)、聚芳酚等线型高聚物;双酚A的卤化、氢化、羟醚化和烯丙基化衍生物,为聚合物提供了很大的改性余地,能合成出性能各异的聚合物材料。它们在机电、仪表、电子、轻工、化工、交通运输和建筑等工业部门得到日益广泛的应用,渗透到现代化技术的各个领域。因此,双酚A制造技术对新型合成材料的应用和发展产     

软聚氯乙烯热可逆交联性的研究

利用Diels-Alder热可逆反应,合成了含有端环戊二烯基(CPD)的硫醇盐,作为具有热可逆性的交联剂,并将其应用于软聚氯乙烯中。研究了交联剂用量、时间及温度对交联程度的影响。采用DTA差热分析对此交联剂的热可逆特性进行了研究,并通过刚果红法和转矩流变仪测试了热可逆共价交联软聚氯乙烯的热稳定性以及加工流动性。     

交联聚苯乙烯的热分解与燃烧性能研究

采用二乙烯基苯(DVB)为交联剂,与苯乙烯(St)单体进行共聚合成了一系列交联聚苯乙烯(PS)。采用热重分析、高温热分解、水平燃烧、氧指数、锥形量热分析等方法研究了交联PS的热分解行为和燃烧性能。结果表明:与线型PS相比,交联PS的热分解温度提高,成炭量增加,热稳定性显著增强;交联PS在燃烧时熔融滴落和发烟量显著减少,热释放速率、质量损失速率和燃烧速率降低,氧指数增加,阻燃性能增强;当St/DVB的质量比为100/3时得到的交联PS的阻燃性能最佳;交联PS在燃烧时生成的大量炭残余物覆盖在聚合物表面形成保护层,对热量传递、氧气和燃料分子的迁移产生屏蔽和阻隔作用,降低了聚合物的热分解速率,提高了其阻燃性能。     

Simpler and more efficient strategy to stabilize the chromophore orientation in electro-optic polymers with copper-free thermal Huisgen reaction

A new strategy is proposed to stabilize the electro-optic (EO) activity of second-order materials using copper-free thermal Huisgen 1,3-dipolar cross-linking reaction. It consists in freezing the chromophores orientation after the poling process by a cross-linking reaction based on the 1,3-dipolar cycloaddition between an azide and an alkyne. To reach this goal, the synthesis of new methacrylate type polymers bearing a derivative of Disperse Red 1 chromophore was performed. The polymeric structure is bearing a cross-linkable function on its backbone and the complementary reactive function is brought by a small molecule called “doping agent” (DA), containing several complementary cross-linking groups, evenly distributed in the polymer film. Materials have been prepared and exhibit large second-order nonlinear optical coefficients (d₃₃) up to 60 pm/V at the fundamental wavelength of 1064 nm. Moreover, the thermal stability of the orientation of the chromophores could reach 150 °C upon cross-linking with such materials, which is higher than previously described cross-linkable EO polymers based on this reaction. Furthermore, this new strategy widens the possibilities offered by copper-free thermal Huisgen 1,3-dipolar cycloaddition as cross-linking reaction for EO polymers.     

Preparation of Silane-Grafted and Moisture Cross-Linked Low Density Polyethylene: Part I: Factors Affecting Performance of Grafting and Cross-Linking

In the present work, the silane grafting and water cross-linking of low density polyethylene (LDPE) were investigated. The grafting reaction was carried out in an internal mixer and polyethylene cross-linking was done in hot water. The effect of silane, peroxide, catalyst, carbon black, cross-linking time, and cross-linking temperature on the grafting and cross-linking processes are reported. Vinyl trimethoxy silane (VTMO) and di-cumyl peroxide (DCP) were selected as grafting agent and initiator respectively. Silane grafting on polyethylene was determined using Fourier transform infrared (FTIR) spectroscopy and torque monitoring of the mixer. Absorption peak due to –Si–OCH₃ groups in FTIR and torque increasing due to silane grafting in the mixer illustrated that silane-grafting reactions occurred. The FTIR data demonstrated that the extent of silane grafting was increased as the concentration of silane and peroxide was increased. Thermogravimetry analysis (TGA) determined that the thermal stability of LDPE increased by increasing the amount of silane grafting. Gel fraction increased with silane and peroxide concentration. As the percent of of catalyst increase the time scale for specified gel content shifted to shorter times. Incorporation of carbon black into LDPE decreased the extent of silane grafting and gel fraction. Water temperature increasing in cross-linking stage reduced the time to maximum degree of cross-linking.     

Sucrose hydrolysis by invertase immobilized on Duolite A-568 employing a packed-bed reactor

The conversion of sucrose to a highly concentrated commercial syrup by immobilized invertase by combining the processes of adsorption and cross-linking using Duolite A-568 as the carrier was studied. Central Composite Design (CCD) was used to assess the effect of glutaraldehyde concentration and cross-linking reaction time on immobilized enzyme activity throughout the hydrolysis of sucrose in a batch reactor. Cross-linking optimization allowed us to find the optimum conditions for activity with a glutaraldehyde concentration of 0.6?g?·?L^?1 and a cross-linking time of 6?h. The temperature and pH that maximized the activity of the immobilized biocatalyst in the cross-linking process were 50°C and 4.0, respectively. Cross-linking allows the biocatalyst to be active at higher temperatures and lower pH. High-sucrose conversions to invert sugar using a continuous fixed-bed reactor were obtained. The immobilized biocatalyst also demonstrated greater thermal stability at low temperatures.     

Investigations on vinylene carbonate. VI. Immobilization of alkaline phosphatase onto poly(vinylene carbonate) -jeffamine® hydrogel beads

Hydrogel-like polymers with reactive cyclic carbonate (CCA) groups have been obtained by the cross-linking reaction of poly(vinylene carbonate) (PVCA) with Jeffamines®. By this reaction, microspheric hydrogel beads with a high water content and a high concentration of reactive CCA groups were prepared. The beads were used as a matrix for the immobilization of the enzyme alkaline phosphatase (ALP) and showed a considerable capacity to couple ALP and a reasonable retention of activity for the immobilized ALP, depending on the reaction conditions. The immobilized ALP exhibited a better thermal stability than did native ALP and a high residual activity was found after repeated use. © 1993 John Wiley & Sons, Inc.     

Thermal Behavior and Degradation Kinetics of Compatibilized Metallocene-Linear Low Density Polyethylene/Nanoclay Nanocomposites

Morphology, thermal degradation and kinetics of metallocene-linear-low-density polyethylene (m-LLDPE)/m-LLDPE-graft-maleic anhydride (m-LLDPE-g-MA)/nanoclay nanocomposites were compared with m-LLDPE/nanoclay, m-LLDPE-g-MA/nanoclay and m-LLDPE/m-LLDPE-g-MA systems. X-ray diffraction measurements revealed intercalated and “highly intercalated” morphologies for the nanocomposites. Thermogravimetric analysis demonstrated that although thermal degradation of m-LLDPE systems were delayed upon the inclusion of nanoclay in air, an inverse effect was perceived for the nanoclay under inert atmosphere. This conclusion was supported by kinetic analysis in terms of reaction order and activation energy. The results obtained from kinetics models also put forward the contribution of m-LLDPE-g-MA, as a compatibilizer, to the thermal stability enhancement through inter-molecular cross-linking augmentation.     

羟丙基纤维素/明胶复合膜的制备及性能表征

以环氧氯丙烷(ECH)作为羟丙基纤维素(HPC)和明胶(GEL)的交联剂,通过均相混合、交联、溶液浇铸、蒸发等工艺制备了一系列ECH交联的HPC/GEL复合膜(EHGF)。利用傅里叶红外光谱(FTIR)、X射线衍射仪(XRD)、紫外-可见分光光度计(UV-Vis)、扫描电子显微镜(SEM)、热重分析仪(TG)、接触角、力学性能等测试手段对EHGF复合膜的结构、微观形貌、热稳定性、耐水性及拉伸断裂强度进行表征和分析。结果表明:交联作用存在于HPC和GEL组分之间,各组分间具有好的相容性;与HPC/GEL共混膜相比,EHGF复合膜显示了更均匀致密的断面形貌和更高的热稳定性,且ECH的交联作用显著提高了HPC/GEL复合膜的水接触角和断裂强度。     

Effects of Silica,Vinyl-Terminated Polydimethylsiloxane (VPDMS) and PMHS-Grafted-POSS (PH) Nanocomposites: Morphology,Thermal Behavior and Mechanical Property

Nanocomposites with different cross-linking agents (PH and PMHS) and silica were prepared. Morphology, thermal and mechanical properties of nanocomposites respectively studied by means of SEM, TGA and universal tensile testing machine. The results revealed that the thermal stabilities and mechanical properties were significantly enhanced by using PH compared with PMHS when silica was added. From the obtained results, it was found that “synergistic” effect of PH on thermal stability and mechanical property of nanocomposites existed. The striking “synergistic” effect of PH on thermal and mechanical properties of nanocomposites was mainly attributed to the organic/inorganic hybrid cross-linking agent of PH.     

热降解动力学方法研究ABS的降解机理

在空气气氛下,采用热重分析(TGA)研究了不同升温速率下丙烯腈-丁二烯-苯乙烯共聚物（ABS）的热降解过程,分别使用Flynn-Wall-Ozawa法和Kissinger法对降解过程进行动力学分析。结果表明,ABS降解包含2个阶段,350~450 ℃之间发生降解反应,同时伴有交联反应,降解活化能（Ea）在200 kJ/mol左右,转化率在80 %~90 %时发生炭化反应,Ea提高到262.81 kJ/mol;500~600 ℃之间是残炭的氧化,Ea降低到130 kJ/mol左右,炭层稳定性较差。ABS的降解过程反应级数为0.946,降解受到随机成核与生长机理控制,降解在ABS基体内进行,而不是表面,所以降解气体燃烧不完全,易产生黑烟和熔融滴落。