Copolycarbonates derived from bisphenol A phthalates

Blocked copolymers from aliphatic diacids and diol-terminated aromatic polyester blocks have been prepared and studied. The preparations of such block copolymers with good molecular weights proved difficult, but a final carbonation reaction enabled the preparation of materials with values of [η] above 1.0. The mechanical and thermal properties of these have been studied and reported.     

Epigenetic Regulation of Autophagy in Cardiovascular Pathobiology

Cardiovascular diseases (CVDs) are the number one cause of debilitation and mortality worldwide, with a need for cost-effective therapeutics. Autophagy is a highly conserved catabolic recycling pathway triggered by various intra- or extracellular stimuli to play an essential role in development and pathologies, including CVDs. Accordingly, there is great interest in identifying mechanisms that govern autophagic regulation. Autophagic regulation is very complex and multifactorial that includes epigenetic pathways, such as histone modifications to regulate autophagy-related gene expression, decapping-associated mRNA degradation, microRNAs, and long non-coding RNAs; pathways are also known to play roles in CVDs. Molecular understanding of epigenetic-based pathways involved in autophagy and CVDs not only will enhance the understanding of CVDs, but may also provide novel therapeutic targets and biomarkers for CVDs.     

合成双酚A催化剂研究新进展

介绍了用于合成双酚A催化剂离子交换树脂的改性、固体酸催化剂,包括分子筛、杂多酸、自主合成固体酸以及离子液体等新型催化剂;分析比较了它们的催化效果;评述了介孔分子筛、杂多酸、离子液体等催化剂的催化性能和存在的问题,并对未来催化剂的发展提出了建议。     

Preparation and properties of bisphenol A polyetherketoneketone based phthalonitrile resins

A promising high temperature phthalonitrile (PN) resin composed of a polyetherketoneketone (PEKK) core bridged by two bisphenol A linkers and end capped with PN groups is presented. This PEKK-PN resin was characterized via differential scanning calorimetry, thermogravimetric analysis, proton nuclear magnetic resonance spectroscopy, scanning electron microscopy, dynamic mechanical analysis, attenuated total reflection Fourier transform infrared, and rheometry. The PEKK-PN resin was evaluated with two different compositions containing 1) 70:30 PEKK-PN to bisphenol A PN (n = 0) and 2) pure PEKK-PN. The 70:30 PEKK-PN resin was mixed with bis[4-(3-aminophenoxy)phenyl]sulfone and exhibited a melt viscosity of 271 cP, much lower than the 657 cP viscosity of the pure PEKK-PN mixture. Void-free PEKK-PN polymers were easily prepared by degassing and curing up to 380°C, resulting in fully crosslinked networks exhibiting thermal stability above 500°C and a 75% char yield. Additionally, the cured PEKK-PN polymer samples displayed good mechanical integrity retaining 50% stiffness at 300°C. This combination of properties suggests these new PEKK-PN resins are excellent materials for high temperature thermosets in composite applications.     

Epoxy resin cured by bisphenol A based benzoxazine

Bisphenol A based benzoxazine was prepared from bisphenol A, formaline, and aniline. This benzoxazine was used as a hardener of the epoxy resin. Curing behavior of the epoxy resin and the properties of the cured resin were investigated. Consequently, curing reaction proceeded without a curing accelerator. The molding compound showed good thermal stability under 150°C, which corresponded to the temperature in the cylinder of injection molding. Above 150°C, the curing reaction proceeded rapidly. The cured epoxy resin showed good heat resistance, water resistance, electrical insulation, and mechanical properties compared with the epoxy resin cured by the bisphenol A type novolac. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1903–1910, 1998     

水杨酸双酚A酯的合成与表征

研究了以水杨酸乙酯、双酚A为原料，二丁基氧化锡为催化剂合成水杨酸双酚A醇，考查了催化剂及用量、反应温度、反应时间及物料配比等因素的影响。结果表明：催化剂用量为0．6g，反应温度为120-130℃，反应时间为4h，物料配比为2．10：1，在此条件下，产率在94%以上。产物结构经元素分析、红外光谱、核磁氢谱进行了表征。     

Reactive Alder‐ene blend of diallyl bisphenol A novolac and bisphenol A bismaleimide: synthesis,cure and adhesion studies

A novel, addition‐curable novolac resin (ABPF) was synthesized by the reaction of diallyl bisphenol A with formaldehyde using p‐toluene sulfonic acid as the catalyst. The synthesis conditions were optimized to obtain soluble polymer of desirable molecular weight distribution which was characterized by FT‐IR, NMR and SEC. ABPF was reactively blended with bisphenol A bismaleimide (BMIP) and cured through an Alder‐ene reaction at high temperatures. The cure characteristics of BMIP–ABPF blend with a maleimide:allyl phenol stoichiometry of 1:1 were studied using FT‐IR, DSC and DMA, which evidenced the multi‐step cure reactions taking place in the system. Cure optimization was evaluated by DSC, DMA and adhesive property tests. The moderately crosslinked blend was conducive for achieving the optimum adhesive properties on aluminium substrates. Retention of the adhesive properties was greater than 100% at 150 °C. © 2001 Society of Chemical Industry     

臭氧氧化双酚A的性能及机理

采用臭氧氧化法在动态条件下降解双酚A,考察了臭氧浓度、水样进水流速、pH、双酚A初始浓度及温度对氧化降解双酚A效果的影响,探究了臭氧氧化双酚A的反应机理。结果表明,臭氧对溶于水中的双酚A具有良好的去除效果,在反应条件(臭氧浓度11.04 mg/L、水样进水流速2 mL/min、原水pH=6.83、双酚A初始浓度10 mg/L、温度40℃)下,去除率达86.12%。增加臭氧浓度或适当升高温度可增加臭氧氧化双酚A去除率。pH和进水流速的提高会降低双酚A去除率。偏酸性条件下,臭氧降解双酚A的效果更好。臭氧氧化双酚A反应活化能较低,属于快速反应。臭氧浓度不变,增加双酚A初始浓度会使其去除率减小。臭氧氧化双酚A以臭氧直接氧化为主,同时也存在羟基自由基间接氧化。     

双酚A反应技术的发展与展望

对双酚Ａ的几种反应技术进行评述,并介绍了近年来的技术发展情况     

双酚A下游产品应用市场分析

综述了双酚A在环氧树脂、聚碳酸酯和阻燃剂中的应用、国内外产能及消费需求变化,分析了双酚A下游产品的市场发展趋势及最新动态。     

A novel solid acid for synthesis of bisphenol A

A novel solid acid was prepared from boric, phosphorous and sulfuric acid by a simple method, and characterized by FT-IR, XRD and TG. Surprisingly, the prepared solid acid is an effective catalyst for the synthesis of bisphenol A from condensation of phenol with acetone. The high conversion of acetone (91.8%) and selectivity of bisphenol A (93.4%) were achieved in the presence of the novel catalyst.     

Solvent effects on the miscibility of poly(methyl methacrylate)/poly(bisphenol a carbonate) blends

Blends of atactic or syndiotactic poly(methyl methacrylate) (designated as aPMMA or sPMMA) and poly(bisphenol A carbonate) (PC) were prepared from solution casting. Tetrahydrofuran (THF) and chloroform were used as solvent. Experimental results indicated that the as‐cast blends from THF were quite different from the chloroform‐cast ones. After film preparation, THF‐cast blends did not show any visible phase separation. However, chloroform‐cast blends formed a phase‐separated structure. The as‐cast PC from either solvent was not completely amorphous, and had a melting point at 239–242°C, indicating a certain degree of crystallinity. In contrast, the quenched samples of aPMMA/PC blends prepared from the two solvents behaved virtually the same. They both showed aPMMA dissolves better in PC, but PC solubility in aPMMA is very little. Using sPMMA instead of aPMMA to blend with PC, different results were obtained. The quenched sPMMA/PC blends cast from THF showed only one T_g. However, immiscibility (i.e., two T_gs) was found in the same blend system when cast from chloroform. THF was believed to cause the observation of single T_g due to the following kinetic reason. sPMMA and PC were still trapped together even after THF removal in a homogeneous, but nonequilibrium state below the glass transition. Therefore, the quenched sPMMA/PC blends were not truly thermodynamically miscible. From the results of aPMMA or sPMMA with PC, increasing syndiotacticity seemed to improve the miscibility between PMMA and PC. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2842–2850, 2001     

Synthesis of a novel luminescent copolymer based on bisphenol A

A new luminescent copolymer (BPAEt₂‐BP; Scheme 1 ), with short alternating divinylbiphenyl units and O‐diethylated bisphenol A (BPAEt₂), was synthesized via the Wittig reaction. The polymer is fully soluble in common organic solvents and has a number‐average molecular weight of 4600 g mol^?1 with a polydispersity index of 1.79. The structure of the polymer was confirmed by ¹H NMR, ¹³C NMR, FTIR and Raman analysis. Thermal analysis of the polymer showed good stability up to 280 °C. Furthermore, polymer film absorbs at 360 nm and emits in the blue at 426 and 451 nm. The band‐gap calculated from the UV‐vis spectrum was about 2.80 eV. A single‐layer device of the configuration indium tin oxide (ITO)/BPAEt₂‐BP/Al has a relatively low turn‐on voltage of 3 V. Copyright © 2005 Society of Chemical Industry     

Molecularly imprinted polyethersulfone microfibers for the binding and recognition of bisphenol A

Bisphenol A (BPA)‐imprinted polyethersulfone (PES) microfibers for the recognition of BPA were prepared by means of wet‐spinning method based on the liquid–liquid phase separation technique. Two kinds of the BPA‐imprinted microfibers were fabricated with the diameters of about 85 μm and 265 μm, respectively. Extraction of BPA from the microfibers was carried out by immersing the imprinted microfibers into ethanol. In the recognition experiments, the binding amounts were about 24.0, 43.0, and 70.0 μmol/g for the nonimprinted microfibers, whereas those were about 50.0, 87.0, 120.0 μmol/g for the imprinted PES microfibers with the diameter of about 85 μm in 100, 200, and 400 μM BPA solution, respectively. Both of the binding amounts and the adsorption rate for the imprinted microfibers with smaller diameter were higher than that for the microfibers with larger diameters. The selectivity results indicated that the BPA‐imprinted microfibers showed higher recognition coefficient (α) for BPA than phenol. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

引进双酚A技术提高企业经济效益

本文介绍了双酚A的应用领域，国内外的供需情况及工艺路线的筛选，并从企业发展的角度提供了可借鉴发展方式。     

丙氧基化双酚A缩水甘油醚的合成与固化性能

以丙氧基化双酚A（D33）、环氧氯丙烷（ECH）和液碱为主要原料,采用两步法工艺合成了丙氧基化双酚A缩水甘油醚（DGEPBA）。考察了原料配比、催化剂用量、反应温度、反应时间等因素对反应的影响。结果表明：开环催化剂三氟化硼-乙醚（BF₃-Et₂O）,质量分数0.1%,D33与ECH的质量比为1∶2.0,反应温度70℃,反应时间2.5h;闭环催化剂苄基三乙基氯化铵质量分数0.2%,D33与NaOH的质量比为1∶2.2,反应温度40℃,反应时间6h时,产物环氧值为0.291eq/100g,产率95.4%,黏度为1180mPa·s。通过FTIR和¹H NMR对产物结构进行表征,并将不同质量分数的DEEBAPO掺入到E-51环氧树脂中,与二乙烯三胺（DETA）进行固化,并对其固化物力学性能进行测试。因为DGEPBA的掺入,使得E-51固化物在抗拉伸、抗冲击方面均有明显提高。热失重（TGA）分析表明固化物热稳定性稍有提高,扫描电镜（SEM）显示断裂面为韧性断裂。     

气提脱酚制备聚碳级双酚A工艺研究

针对传统的精馏法、结晶法及刮膜蒸发法脱酚工艺存在的诸多弊端,有必要对新的脱酚工艺进行研究,以制备超低游离酚质量分数的聚碳级双酚A。鉴于双酚A-苯酚物系高沸点、热敏性特性,文中以降膜蒸发脱除大部分苯酚、获得的粗双酚A为原料,采用向真空填料塔通入过热水蒸气进行气提的方法,研究制备超低游离酚质量分数聚碳级双酚A的脱酚工艺。研究结果表明:气提塔的操作压力、水蒸气温度和流量对脱酚效果有很大的影响。操作压力越低,组分间相对挥发度增大,脱酚效果越好。但过低的压力对脱酚效果的改善将不明显,带来的负面影响是设备投资的增加;水蒸气温度越高,塔内物料温度也随之升高,苯酚的饱和蒸汽压增大,脱酚效果越好;水蒸气流量越大,在操作压力不变的情况下,苯酚的气相分压就越低,脱酚效果越好。适宜的工艺条件是:操作压力为4.0—5.0 kPa;气提水蒸气温度185—190℃,流量为处理量的2%。     

巯基助催化剂对双酚A催化剂活性影响

选择4种不同结构的巯基试剂青霉胺、二甲基色胺、N,N-二乙基-4-巯基丁胺和N,N-二甲基-3-巯基丙胺对主催化剂改性,并进行活性评价,结果表明,N,N-二甲基-3-巯基丙胺对双酚A催化剂改性效果最佳,在苯酚与丙酮物质的量比10∶1、反应温度(60~90)℃、空速1 h-1及催化剂用量20 m L条件下,丙酮转化率大于91%,双酚A选择性大于97%。在实验室条件下,助催化剂用量0.7 g和改性时间2 h时,双酚A催化剂活性最好。     

巯基改性双酚A催化剂的制备及其催化活性

制备了巯基改性双酚A催化剂,连续评价试验表明,该催化剂具有催化活性高、选择性好和活性稳定等优点,综合性能达到工业应用技术指标要求。     

聚碳级双酚A结晶精制过程的研究

研究了以甲苯为溶剂,从双酚A-苯酚的加合物晶体中,用结晶方法制备双酚A的精制工艺,讨论了加合物晶体中苯酚的质量分数、结晶终温、结晶时间、溶剂比对双酚A的结晶收率、产品熔点和产品色号的影响,得出了用甲苯溶剂结晶法从加合物晶体中提纯具有特殊用途的聚碳级双酚A晶体的适宜工艺条件为溶剂摩尔比0∶1,结晶终温38℃,结晶时间190 m in。