浅谈聚碳酸酯的生产工艺及发展方向

介绍了聚碳酸酯(PC)的合成工艺路线,对光气法、酯交换法及全非光法各自的优缺点作了比较,指出了全非光法是绿色环保工艺路线,代表PC生产技术发展的方向。     

CO2催化转化制碳酸丙烯酯研究进展：催化剂设计、性能与反应机理

CO₂催化转化合成碳酸丙烯酯（PC）是CO₂资源化循环利用的典型反应，同时产物PC作为重要的极性溶剂和聚合物单体在锂离子电池和高性能聚合物等关键领域的需求激增，因此受到科研界和工业界的关注。本文简要介绍了从CO₂出发催化转化合成PC的现有反应路径，详细介绍了目前应用最广泛的CO₂-环氧丙烷（PO）羧基化反应体系，包括CO₂-PO羧基化反应涉及的各种均相和非均相催化体系及其近期研究进展，重点总结了催化剂的设计、构效关系与反应机理。最后，提出了为实现CO₂-PO羧基化合成PC工艺的可持续发展所需解决的问题，并对此提出了解决思路和未来发展方向，以期为CO₂高效转化为绿色环保化学品PC技术的发展提供参考。     

全非光法聚碳酸酯生产工艺概述

分步概述了全非光法合成聚碳酸酯(PC)的生产工艺技术,包括以CO2和环氧丙烷(PO)为原料合成碳酸丙烯酯,碳酸丙烯酯和甲醇(M)进行酯交换生产碳酸二甲酯(DMC)、DMC与苯酚(PH)酯交换反应合成碳酸二苯酯(DPC)、DPC与双酚A(BPA)熔融缩聚制得PC,对各工序所存在的生产工艺问题进行分析并提出了改进方向.     

高分子材料的新型注射成型技术

概要地介绍了气体辅助成型法、注射压缩成型法、模具滑合成型法、剪切场控制取向成型法、硬化PC薄片表面镶嵌成型法及直接注射成型法等若干种用途较为广泛的注射成型新技术的原理,并介绍了高分子材料注射成型技术的发展动向.     

新型增韧剂对PBT/PC合金增韧的研究

以双烯烃、苯乙烯、甲基丙烯酸甲酯为单体,采用种子聚合技术,合成了具有核-壳结构的接枝共聚物(MIS树脂),并与PBT/PC合金共混.结果表明,MIS树脂为15～18份时,PBT/PC合金的冲击强度最大.加入MIS树脂后,PBT/PC合金的断层明星,而且出现了很多小空洞,提高了PBT/PC合金的力学性能.MIS树脂可以用...     

CO_(2)基生物可降解聚碳酸酯研究进展北大核心

综述了CO_(2)基生物可降解聚碳酸酯(PC)合成催化剂研究进展、PC的用途及PC的生产现状。开发生产具有生物可降解和生物相容性好的聚合物,是实现CO_(2)减排目标的重要手段,也是CO_(2)资源化利用的重要途径。随着研究的深入,合成CO_(2)基生物可降解塑料所用催化剂的活性和链基碳酸酯选择性不断提高,CO_(2)基PC的生产成本不断下降,生产规模和应用范围不断扩大,对传统PC的取代成为趋势,一个以CO_(2)为主要原料的PC产业将迎来发展高潮。     

新型固碳工艺思路及技术研究

综述了固碳技术的研发历程,从资源化利用的角度看,CO2是一种大存量的“碳源”,化学固碳兼具碳减排和资源化的优势,是未来固碳技术的重点发展方向。基于化学固碳技术存在的问题及已形成的技术成果,将CO2资源化利用工艺与现有新材料合成工艺相结合,提出了以CO2为基础原料深度延伸产业链生产聚碳酸酯,并形成多元化产品结构、具备工业化实施条件的新型固碳工艺。针对新工艺主要涉及到的CO2合成尿素、尿素法DMC、酯交换法DPC、异丙苯法苯酚工艺、离子交换树脂法BPA合成工艺及非光气法PC等生产过程,进行了技术可行性分析。     

聚碳酸酯合成工艺研究进展

聚碳酸酯（PC）是一种重要的工程塑料,目前主要有双酚A型PC和异山梨醇型PC两种聚碳酸酯。系统综述了这两种聚碳酸酯的各种合成工艺,并重点介绍了非光气熔融酯交换法催化剂的研究进展。传统熔融酯交换催化剂存在催化活性低、金属污染等问题,因此,开发高活性以及绿色环保的离子液体催化剂对熔融酯交换工艺的发展具有重大意义。     

双酚F的合成及其应用研究综述

本文介绍了目前国内外双酚F生产的技术路线,以及双酚F在环氧树脂、PC树脂、酚醛树脂、聚酯树脂等合成材料中的应用,并重点对双酚F型和双酚A型环氧树脂的性能进行了比较。     

减水保坍复合型聚羧酸减水剂的研制

基于聚羧酸型减水剂(PC)分子结构的可设计性,选用烯丙基聚氧乙烯醚(APEG,相对分子质量为2000),异丁烯醇聚氧乙烯醚(HPEG,相对分子质量为2400),异戊烯醇聚氧乙烯醚(TPEG,相对分子质量为2700)等三种不同类型聚醚产品作为合成单体,与丙烯酸(AA)在不同酸醚物质的量比的条件下分别合成一系列PC,并从三种聚醚单体合成的PC中各选一种分散减水效果最好的,再分别引入2-羟基丙烯酸乙酯(HEA)单体,替代部分丙烯酸进一步聚合以改善PC的保坍能力。最后,通过砂浆和混凝土拌合物试验,对合成产品的性能进行验证。结果表明:不同类型聚醚,都存在一个最佳的酸醚物质的量比以达到其所合成PC的最大减水率,此外还有一个最佳的HEA替代AA比例以实现合成PC减水保坍的协调统一。     

Regulation of intestinal apolipoprotein A-I synthesis by dietary phosphatidylcholine in newborn swine

Phospholipid (PL) from both dietary sources and biliary secretions may be important in the regulation of intestinal apolipoprotein (apo) synthesis. We previously demonstrated the up-regulation of apo A-I secretion by phosphatidylcholine (PC) in a newborn piglet intestinal epithelial cell line. We hypothesized that dietary PC increases small intestinal apo A-I synthesis in vivo in the newborn piglet. Two-day-old female swine were fed by gavage for 48 h. Diets consisted of a formula containing 51% of calories as triacylglycerol providing 180 kcal/kg/24 h. The experimental group (+PC, n=7) received 1 g/L added soybean PC, and the control group (−PC, n=7) received no added PC. At the end of the study period, jejunal apo A-I, B, and A-IV synthesis was measured, and apo A-I mRNA levels were quantitated. Jejunal mucosal PI content and serum lipids and apo B and A-I levels were measured. Jejunal apo A-I synthesis was almost twice as high in the +PC group as compared to the −PC group with no difference in apo A-I mRNA levels. Jejunal content of PL was higher in the +PC group than in the −PC group. There were no differences in jejunal apo B and A-IV synthesis or serum levels of lipids and apo-lipoproteins between the two groups. Dietary PC supplementation in newborn swine up-regulated jejunal apo A-I synthesis. Apo A-IV synthesis, which is sensitive to fatty acid flux, was not significantly increased, which suggests a specific effect of PC on apo A-I synthesis. Lumenal PC may be important in the regulation of intestinal apo A-I synthesis in the neonate.     

环氧丙烷与二氧化碳合成碳酸丙烯酯

介绍了PC的性质、应用情况和生产工艺。通过对影响合成PC的主要因素和机理的讨论,指出催化剂和溶剂是影响PC收率的重要因素,较高的压力对提高产品的选择性有利。     

碳酸丙烯酯生产方法及热能综合利用

介绍了几种碳酸丙烯酯的合成方法,重点阐述了二氧化碳与环氧丙烷直接合成碳酸丙烯酯的工艺,并以精馏碳酸丙烯酯为例,介绍了该工艺过程中反应热的利用方法。     

Effects of phosphatidylcholines on de novo synthesis and excretion of sterol by L-929 fibroblasts

The effects on [¹⁴C] sterol synthesis and excretion by exposure of L-929 cells to several phosphatidylcholines (PC) has been examined. No significant effects were noted on either parameter during a 6-hr period if exposure of cells to the phospholipid preceded the addition of [1-¹⁴C] acetate by just 30 min. However, if cultures were grown in media containing delipidized serum and 2×10⁻⁵ M PC through 2 or more subculturings prior to adding [1-¹⁴C] acetate, the amount of [¹⁴C] sterol increased in both cells and medium by 70–200% when saturated or monounsaturated PC were used. Dilinoleylphosphatidylcholine (18∶2 PC) at the same concentration did not stimulate synthesis or excretion of newly synthesized sterol. Total cellular sterol was determined by gas chromatography, and was only marginally affected by long-term exposure to dipalmitylphosphatidylcholine (16∶0 PC), whereas the total sterol of the medium increased by 4-fold over a 19-hr period. Cultures which had been exposed to 16∶0 PC through 3 subculturings continued to display enhanced de novo sterol synthesis, but not excretion, for up to 5 hr after replacement with fresh medium lacking 16∶0 PC. The disparity in response to 2×10⁻⁵ M levels of 16∶0 PC and 18∶2 PC may relate to differences in metabolism of cellular fatty acids, whereas relatively small changes in the cellular fatty acid composition were noted with 16∶0 PC-treated cells. The results indicate that extracellular PC can promote sterol synthesis and excretion by L-929 cells, and that the magnitude of this response is influenced by the time of exposure to the phospholipid and by its fatty acid composition.     

Modulation of phosphatidylcholine biosynthesis by peroxisome proliferating fatty acid analogues

The modulation of phosphatidylcholine (PC) and phosphatidylethanolamine (PE) biosynthesis by sulfur-substituted fatty acid analogues has been investigated in rats. We have compared the effects of two non-β-oxidizable fatty acid analogues, 3-thiadicarboxylic acid and tetradecylthioacetic acid, which induce proliferation of peroxisomes, with those of the analogue tetradecylthiopropionic acid, which is a weak peroxisome proliferator. Repeated administration of 3-thiadicarboxylic acid for seven days resulted in increased hepatic concentrations of both PC and PE, but the PC/PE ratio was decreased. PC synthesis was increased, as evidenced by increased incorporation of [³H]choline into PC and an increased activity of cytidinetriphosphate (CTP): phosphocholine cytidylyltransferase. This was accompanied by a reduction in the pool sizes of choline and phosphocholine. TheS-adenosylmethione/S-adenosylhomocysteine ratio (AdoMet/AdoHcy) was marginally affected, indicating no increase in the rate of methylation of PE to PC. Administration of tetradecylthioacetic acid also resulted in increased hepatic phospholipid levels, increased AdoMet/AdoHcy ratios and in slightly elevated activity of CTP:phosphocholine cytidylyltransferase. The most striking effect observed after tetradecylthiopropionic acid treatment was the development of fatty liver. The activity of CTP:phosphocholine cytidylyltransferase and the incorporation of [³H]choline into PC was reduced compared to 3-thiadicarboxylic acid treatment. Although the rate of methylation of PE seemed to be increased at an elevated AdoMet/AdoHcy ratio, this resulted in only minor changes in the hepatic PC and PE levels, and the PC/PE ratio remained unchanged. Furthermore, the hepatic levels of choline and phosphocholine were reduced in these rats. The activities of the two enzymes competing for choline in the liver, choline kinase and choline dehydrogenase were changed in opposite directions, with the activity of choline kinase increasing approximately 1.5-fold. In addition, it was found that the level of homocysteine was elevated in the liver of tetradecylthiopropionic acid-treated rats. The possibility is discussed that this reflects a reduced flux of choline through the oxidative pathway in the liver. In tetradecylthiopropionic acid-treated rats, there seemed to be a coordinated regulation of the two pathways for PC biosynthesis, with an increase in the methylation of PE to PC and a reduced synthesisvia the CDPcholine pathway. The increase in PC observed in rats treated with 3-thiadicarboxylic acid and tetradecylthioacetic acid suggests that increased PC synthesis is linked to peroxisome proliferation.     

A new,nonphosgene route to poly(bisphenol a carbonate) by melt‐phase interchange reactions of alkylene diphenyl dicarbonates with bisphenol A

This article describes a new, nonphosgene method for the synthesis of poly(bisphenol A carbonate) (PC). The method involves three steps: the reaction of an aliphatic diol with phenyl chloroformate to form an alkylene diphenyl dicarbonate, the reaction of the alkylene diphenyl dicarbonate with bisphenol A to produce an aromatic–aliphatic polycarbonate, and the thermal treatment of the polycarbonate at 180–210°C under a stream of nitrogen with Ti(OBu)₄ to give PC and a cyclic alkylene carbonate. The method furnished low to moderate molecular masses of PC upon the complete elimination of the aliphatic moieties. The approach may be considered a new method, based on polycarbonate thermochemical degradation, for the synthesis of cyclic aliphatic carbonates. The obtained polymers were characterized by intrinsic viscosity and IR, ¹H‐NMR, and ¹³C‐NMR spectroscopy. The thermal treatment step was conducted in a glass reaction tube at 180–210°C under a stream of nitrogen, and the reaction was completed by heating to 250°C. In the thermal treatment step, semisolid effluents composed of cyclic alkylene carbonates were formed and subsequently eliminated from the reaction mixture. Heating to 250°C under nitrogen or under a dynamic vacuum furnished the pure aromatic PC residue. This intrachange reaction provides a flexible method for the synthesis of polycarbonates with alkylene diols containing two or three methylene groups, from which the pure PC homopolymer can be prepared. The potential of this approach was demonstrated by the successful synthesis of PC homopolymer from five different polycarbonates with a bisphenol A unit linked to 1,2‐propylene, 1,3‐propylene, 2‐methyl‐1,3‐propylene, 2,2‐dimethyl‐1,3‐propylene, and 1,3‐butylene as the alkane chains. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

窄带隙共轭聚合物/富勒烯衍生物光探测器件的研究

基于高灵敏度、宽光谱响应的窄带隙共轭聚合物光探测器件的研究取得了突破性进展,受到了学术界和产业界的高度重视,成为了当前光探测器件研究的热点课题之一.本文概述了窄带隙共轭聚合物作为电子给体与电子受体PC61BM下光伏器件的研究进展及存在的问题.提出了带隙更窄、光谱响应更宽的共轭聚合物的合成与器件的优化研究将具有更大的发展...     

An enzymatic method for the synthesis of mixed-acid phosphatidylcholine

The enzymatic synthesis of PC with decanoic acid in the sn-1 and hexanoic acid in the sn-2 position is described. The procedure comprises the following enzymatic steps: (i) treatment of egg yolk with phospholipase A₂ (PLA₂) to hydrolyze egg yolk PC to 1-acyl lysophosphatidylcholine (LPC); (ii) esterification of 1-acyl LPC with hexanoic acid catalyzed by PLA₂ to yield PC with hexanoic acid in the sn-2 position; (iii) removal of the FA in the sn-1 position by lipase-catalyzed ethanolysis to yield 2-hexanoyl LPC; and finally (iv) introduction of decanoic acid in this position by lipase-catalyzed esterification of 2-hexanoyl LPC to yield 1-decanoyl-2-hexanoyl-PC. Two egg yolks with a weight of 16 g were required to obtain 160 mg of the desired product. The chemical purity of the PC product and the positional purity of the FA were around 99%. The method is applicable for the synthesis of other mixed-acid PC species as well.     

国内外PC/ABS合金的生产与研究

综述了国内外聚碳酸酯(PC)/丙烯腈-丁二烯-苯乙烯共聚物(ABS)合金生产商的生产能力和实际产量、国内外PC/ABS合金市场和价格,对国内PC/ABS合金技术现状及其市场发展趋势进行了分析和预测。另外,还介绍了国内外科研开发、技术进展以及新产品开发情况。