间歇式本体法PP装置闪蒸釜氮气连续汽提工艺研究

在间歇式本体法聚丙烯(PP)装置上研究了闪蒸釜氮气置换工艺,分析测试了闪蒸釜反复抽真空充压工艺和闪蒸釜连续汽提工艺在置换效果、氮气耗量、排人气柜氯气量、携带粉料量、置换时间等.结果表明:与反复抽真空充压工艺相比,闪蒸釜连续汽提工艺能够明显降低间歇式本体法PP装置的丙烯单耗、氮气消耗和污染物排放.     

液相本体聚丙烯脱氯工业试验

千吨级液相本体聚丙烯脱氯工业试验,采用釜式间歇法脱氯工艺,以环氧丙烷和水为脱氯剂,物料配比为:PP:环氧丙烷:水=100:0.33～1.0:0.3～1.0;反应温度110℃;反应时间1h。采用本脱氯工艺可以使产品氯含量由100～200ppm降低到50ppm以下.脱氯后的产品经应用证明,对后加工设备没有腐蚀。采用本工艺,脱氯釜可用1Cr18Ni9Ti材质,4m~3脱氯釜采用夹套传热方式可节省能量和氮气。试验结果表明,本脱氯工艺可行,技术成熟,可以用于千吨级液相本体法聚丙烯生产。     

BLF43型预聚合釜的开发及结构特点

简要介绍了BLF43型预聚合釜的结构特点,该釜应用于本体法PVC树脂的生产,较好地满足了工艺要求。     

2.0万t／a小本体聚丙烯聚合单元设计优化

对某厂２．０万ｔ／ａ聚丙烯装置聚合釜的数量提出建议，通过计算得出用６台聚合釜代替原设计的８台聚合釜，呵满足设计生产能力要求，节省投资。     

苯乙烯系树脂连续本体聚合某些工程问题的探讨

本文论述了聚苯乙烯树脂连续本体聚合工艺的优点,建立试验装置的必要性;本体聚合的关键在于解决高粘物的传热、输送、脱挥和反应器的形式等问题。并从动力学角度分析树脂特性,对比了已有技术的原料、能耗和产品质量;我国开发HIPS宜采用单体汽化的CSTR首釜,多个PFR串联后聚釜的生产工艺。     

本体法氯乙烯聚合釜搅拌试验分析

通过试验研究了搅拌器功率特性和流动状态,分析了本体法氯乙烯聚合的预聚合釜和聚合釜的搅拌性能。     

浅谈顺丁橡胶装置三釜凝聚技术

介绍顺丁橡胶装置中两釜凝聚和三釜凝聚工艺的工艺过程。分析了三釜凝聚的工艺特点和生产中的优势。     

本体法PVC预聚釜和聚合釜的研制

概述了国内引进的本体法PVC 30 m~3预聚釜和50 m~3聚合釜的结构和特性。介绍了国产本体法PVC 42 m~3预聚釜和70 m~3聚合釜的放大研制过程及技术特点,指出该型釜在应用几何相似原则进行尺寸放大的同时须匹配提升聚合釜传热能力。国产本体法PVC 42 m~3预聚釜和70 m~3聚合釜的研制成功提高了我国聚合釜的技术水平,将对我国PVC行业产生重大影响。     

南京炼油厂聚丙烯装置的技改措施

介绍了南京炼油厂间歇式液相本体法聚丙烯装置的几项技术改造措施：优化聚丙烯生产工艺，提高单釜产量和质量；改造聚合釜、闪蒸罐的润滑系统；正确选用聚合釜的轴封填料。     

间歇式液相小本体聚丙烯工艺现状及优化措施

随着丙烯和聚丙烯生产工艺的多元化、大型化、一体化,间歇式小本体聚丙烯聚合装置生存空间越来越小。本文分析了小本体聚丙烯工艺和SPG(丙烯“液相本体聚合+卧式釜气相聚合”组合)聚丙烯工艺在丙烯单耗、能耗、人工成本等方面的差距,并阐述了变压吸附技术、不同催化剂、自动化控制、外循环撤热、停用溴化锂制冷等措施的应用效果,来降低小本体装置生产成本。     

Miscibility, crystallization and melting behaviour, and morphology of binary blends of polycaprolactone with styrene-co-maleic anhydride copolymers

Blends of polycaprolactone (PCL) and random copolymers of styrene and maleic anhydride (SMA) with different maleic anhydride contents were prepared by the coprecipitation technique. The miscibility of both polymers in the melt and in the solid state was studied by means of optical microscopy, light transmission measurements and dynamic mechanical analysis. The crystallization behaviour of PCL in the miscible blends was examined using optical microscopy and the morphology of the semicrystalline PCL/SMA blends was investigated by means of small-angle X-ray diffraction measurements. Their melting behaviour was studied by differential scanning calorimetry. SMA containing 14 and 25 wt% MA was found to be miscible with PCL over the entire composition and temperature range (up to 200°C). SMA appears to segregate interlamellarly during the isothermal crystallization of PCL. The double melting behaviour of PCL in the blends was attributed to a secondary crystallization process and not to a partial melting-recrystallization-remelting process.     

Synthesis and characterization of alkali‐modified styrene‐maleic anhydride copolymer for dispersion of TiO2

A copolymer of styrene and maleic anhydride was synthesized by free radical polymerization at 80°C using N,N‐dimethylformamide (DMF) as solvent and benzoylperoxide as initiator. The monomer feed ratio of styrene to maleic anhydride was varied in the range of 1 : 1 : to 3 : 1. The polymer yield was found to decrease with increase in styrene in the feed. The molecular weight of copolymers which were formed by taking styrene to maleic anhydride ratio of 1 : 1, 2 : 1, and 3 : 1, as determined by Ostwald Viscometery were about 1862, 2015, and 2276 respectively. The acid values of abovementioned three copolymers were found to be 480, 357, and 295, respectively. The typical viscosity values of 20% solids in ammonical solution of copolymers formed by taking feed ratios of Sty : MAn as 1 : 1 and 2 : 1 were 26 and 136 cp, respectively. For the feed ratio 3 : 1, a gel was formed. The synthesized copolymers were hydrolyzed by alkalis, namely, NaOH, KOH, and NH₄OH. The dispersing ability of hydrolyzed styrene‐maleic anhydride (SMA) copolymers for dispersion of titanium dioxide was studied. The modified SMA copolymers were found to be effective dispersants for TiO₂. Among the three alkalis studied, the Sodium salts of SMA were found to give better dispersion. The copolymer having a 1 : 1 feed ratio showed the best dispersing ability for TiO₂ particles among the three ratios studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3194–3205, 2007     

苯乙烯-马来酸酐无规共聚物合金

分别介绍了苯乙烯—马来酸酐共聚物(SMA)与通用树脂、工程树脂共混制取合金后的力学性能；提供了透明、抗冲SMA本身性能改善的途径，以及改善其他树脂性能的思路；列举了三元乙丙橡胶接枝物、丙烯腈—丁二烯—苯乙烯三元共聚物增韧SMA效果，以及抗冲SMA改善聚对苯二甲酸乙二酯等树脂性能的效果。接枝物或增容剂的使用能有效地提高合金性能。     

Preparation of well‐defined block copolymer having one polystyrene segment and another poly(styrene‐alt‐maleic anhydride) segment with RAFT polymerization

Block copolymers, polystyrene‐b‐poly(styrene‐co‐maleic anhydride), have been prepared by reversible addition‐fragmentation chain transfer (RAFT) polymerization technique using three different approaches: 1‐phenylethyl phenyldithioacetate (PEPDTA) directly as RAFT agent, mediated polystyrene (PS) block as the macromolecular PS‐RAFT agent and mediated poly(styrene‐maleic anhydride) (SMA) block with alternating sequence as the macromolecular SMA‐RAFT agent. Copolymers synthesized in the one‐step method using PEPDTA as RAFT agent possess one PS block and one SMA block with gradient structure. When the macromolecular RAFT agents are employed, copolymers with one PS block and one alternating SMA block can be produced. However, block copolymers with narrow molecular weight distribution (MWD) can only be obtained using the PS‐RAFT agent. The MWD deviates considerably from the typical RAFT polymerization system when the SMA is used as the RAFT agent. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Blends of bisphenol A polycarbonate and rubber‐toughened styrene–maleic anhydride copolymers

The morphology and mechanical properties of polycarbonate (PC) blends with rubber‐toughened styrene–maleic anhydride copolymer materials (TSMA) were investigated and compared with the properties of blends of PC with acrylonitrile–butadiene–styrene (ABS) materials. The PC/TSMA blends showed similar composition dependence of properties as the comparable PC/ABS blends. Polycarbonate blends with TSMA exhibited higher notched Izod impact toughness than pure PC under sharp‐notched conditions but the improvements are somewhat less than observed for similar blends with ABS. Since PC is known for its impact toughness except under sharp‐notched conditions, this represents a significant advantage of the rubber‐modified blends. PC blends with styrene–maleic anhydride copolymer (SMA) were compared to those with a styrene–acrylonitrile copolymer (SAN). The trends in blend morphology and mechanical properties were found to be qualitatively similar for the two types of copolymers. PC/SMA blends are nearly transparent or slightly pearlescent. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1508–1515, 1999     

低温合成苯乙烯-马来酸酐交替共聚物

苯乙烯(St)和马来酸酐(MA)自由基引发共聚反应,生成共聚物SMA,是典型的交替共聚。在过氧化苯甲酰(BPO)引发下,以丙酮为溶剂,采用溶液聚合法合成苯乙烯-马来酸酐共聚物,并用收率作为评价标准,对反应条件进行研究。结果表明,在温度为60℃,BPO的质量分数x(BPO)=0.3%,n(苯乙烯)∶n(马来酸酐)=1∶1,w(单体)=30%,反应2 h的条件下,聚合物的收率可达到98.5%。利用化学滴定法测得聚合物中马来酸酐摩尔分数为49.91%,结合理论,证明了合成的苯乙烯-马来酸酐共聚物是一种交替共聚物。一种低温合成苯乙烯-马来酸酐交替共聚物的工艺得到开发。     

SMA树脂工艺过程的中试研究

概要介绍了苯乙烯－马来酸酐共聚物的中试工艺流程和试验结果,中试研究已取得成功,可以为工业规模装置提供基础设计。     

Structure and properties of blends of poly(ethylene-co-vinyl alcohol) with poly(styrene-co-maleic anhydride)

In the present study, ethylene/vinyl alcohol (EVAL) copolymers with different hydroxyl contents were melt mixed with styrene/maleic anhydride (SMA) copolymers. These two copolymers have functional groups capable of reacting intermolecularly, giving stable products. All EVAL copolymers were prepared from the same ethylene/vinyl acetate (EVA) copolymer by controlled hydrolysis. The blends, prepared at constant temperature and rotation speed in the rheomixer, were characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and thermo-gravimetric analysis, as well as mechanical properties and extraction experiments. All the above measurements lead to the conclusion that a certain part of hydroxyls of EVAL have reacted with anhydride groups of SMA, leading to the formation of branched and cross-linked products. The effect of (1) the molar ratio of hydroxyl/maleic anhydride functional groups, (2) the overall concentration of the functional groups, and (3) the mixing time on the structure and properties of the blends are discussed. Emphasis is given on the influence of these factors on the tensile strength, the elongation at break, and impact strength of the products. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 983–999, 1997     

An IGC Study of Interactions in SAN/SMA Blends

Inverse gas chromatography has generated surface energy and acid-base interaction data for copolymers of styrene/acrylonitrile (SAN) and styrene maleic anhydride, (SMA) at mole per-cent compositions of SAN-26, SMA-26, and SMA-18. Also measured were polymer pair interaction data for 1:1 weight ratio blends of the copolymers. Explicit values of the X interaction parameter over wide temperature ranges also were obtained from these experiments. SAN was shown to be amphoteric, while SMA polymer surfaces interact as bases. The surface and bulk compositions differ both in single copolymers and polymer blends, with an excess of styrene moieties at surfaces and interfaces resulting from thermodynamic drives to minimize the relevant energies. Miscibility-immiscibility relationships in polymer blends are strongly temperature-dependent. Blends were shown to be miscible below glass transition temperatures, and again at temperatures above about 190°C, with immiscible conditions between these temperature ranges.     

Grafting cellulose acetate with styrene maleic anhydride random copolymers for improved dimensional stability of cellulose acetate

Graft copolymers of cellulose acetate (CA, d.s.:2.45) with styrene maleic anhydride random copolymers (SMAs) were synthesized by reacting the hydroxyls on CA backbone with the anhydride on SMA. The formation of graft copolymers leads to compatibilized blends with microscopic phase domains under appropriate conditions. The grafting reaction was studied in detail. The uniform dispersion of SMA in the CA matrix brings new properties to the grafting reaction products. Tests from acetone-cast films showed improved dimensional stability in comparison to cellulose acetate; i.e., in the presence of 50% SMA in the formulation, there is more than 50% reduction on the dimensional change as compared to CA. The dimensional stability of the grafting products is better or comparable to cellulose triacetate. There are, for the alloys, reduced moisture adsorption, improved tensile strength, tensile modulus, reduced elongation, as compared to cellulose acetate. © 1994 John Wiley & Sons, Inc.