Dow 化学公司本体法工艺及部分ABS产品

综述了美国Dow化学公司本体法生产丙烯腈－丁二烯－苯乙烯三元共聚物（ABS）工艺的演进过程。介绍了该公司根据产品特点和国外市场情况制定的推销策略。通过了解Dow化学公司改善其产品多样性的途径，为我国本体法生产ABS产品及其后续产品的开发应用提供参考。     

苯乙烯连续搅拌釜式本体聚合工业过程模拟

采用了机理分析建模法对苯乙烯工业本体预聚过程进行了模型化研究，并通过对流体在反应器中混合模式的分析，表明预聚釜可视作全混流（CSRT）反应器模型，此外对热聚合机理中的引发级数和终止反应进行了考察，利用预聚釜的工业数据确立了三分子引发，同时考虑偶合和歧化终止以及向溶剂链转移的反应机理模型，并选取了合适的动力学参数，然后利用工业装置采集的数据进行了模拟，从宏观转化率，平均分子量和微观分子量分布两个方面对模型进行了验证，模拟结果和工业数据符合得较好，该模型方程不仅能模拟稳态，非稳态预聚过程，同时也为装置开发新产品，改造扩建，优化操作方案等提供了理论基础。     

本体法ABS和乳液法ABS共混研究

将本体法丙烯腈-丁二烯-苯乙烯共聚物(ABS)和乳液法ABS共混,研究了共混体系的力学性能。结果表明:当本体法ABS质量分数为30%～50%时,共混体系的悬臂梁缺口冲击强度高于单组分的性能,与本体法ABS相比,增幅可达28%;拉伸强度和弯曲强度介于共混前2种ABS之间。动态力学研究表明,来自于2种工艺ABS中的苯乙烯-丙烯腈共聚物相容性良好。     

连续本体法ABS制备工艺进展

综述了连续本体法丙烯腈/丁二烯/苯乙烯(ABS)的制备工艺、接枝和相反转过程的工艺特征、调控粒径及改进性能的方法,指出各种制备工艺的共性和区别,总结出连续本体法ABS制备工艺的关键.     

SMA树脂的本体—悬浮法合成及表征研究

研究了本体 -悬浮聚合法合成SMA(苯乙烯 -马来酸酐无规共聚物 )树脂的工艺条件 ,考察了本体共聚阶段引发剂种类、引发剂浓度、聚合温度、马来酸酐加料方式、马来酸酐滴加时间、滴加液中马来酸酐与苯乙烯的配比等因素对共聚转化率和SMA组成的影响。加入PVA(聚乙烯醇 )水溶液和补加BPO(过氧化苯甲酰 )进行悬浮聚合 ,并进行了放大试验 ,合成出马来酸酐含量为 5 %～15 % (质量含量 ,下同 )的SMA和PS共混物 ,其中SMA约占 90 %～ 95 %。用双螺杆挤出机挤出造粒得成品SMA树脂。对合成出的SMA树脂进行了DSC、热变形温度及力学性能等的测试 ,分析了MA(马来酸酐 )含量对SMA树脂性能的影响     

高分子量苯乙烯—马来酸酐共聚物

介绍了高分子量SMA的国内外研究,应用状况。讨论了其合成工艺、技术路线、共聚物的结构和组成的表征方法。随着高分子量SMA生产工艺在我国的工业化,其在聚合物合金、共混物和复合材料领域的应用开发也会相应加快。     

ABS连续本体聚合技术的研究进展

介绍了近年来丙烯腈-丁二烯-苯乙烯共聚物(ABS)连续本体聚合技术的最新进展,重点介绍了连续本体聚合的工艺和研究方向,并展望了国内的发展趋势。     

连续本体法合成ABS树脂

以3釜串联连续本体聚合工艺合成了(丙烯腈/丁二烯/苯乙烯)共聚物(ABS),并研究了其力学性能。结果表明,在一定橡胶含量条件下,采用双嵌段丁苯橡胶替代聚丁二烯橡胶可使ABS树脂的综合力学性能得以提高;双嵌段丁苯橡胶质量分数每增加0.1%,可使ABS树脂的冲击强度提高约0.98～1.67 kJ/m2,但其耐热性有所下降,拉伸强度和弯曲强度存在峰值。为获得均衡的性能,(苯乙烯/丙烯腈)共聚物(SAN)树脂相重均相对分子质量应控制在2.0×105～2.5×105,高于2.5×105之后,ABS树脂性能提升不明显。与乳液法ABS树脂相比,连续本体法ABS树脂具有极低的残余单体含量,有明显的环保优势。     

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.     

连续本体法聚苯乙烯中试装置的开发

设计开发了我国第一套5kg/h连续本体法聚苯乙烯中试装置。该装置顺利开车并成功生产出通用级聚苯乙烯和高透明抗聚苯乙烯。     

Study on controlled radical alternating copolymerization of styrene with maleic anhydride under UV irradiation

The copolymerization of styrene with maleic anhydride (MAh) in the presence of 1‐(ethoxycarbonyl)prop‐1‐yl dithiobenzoate was carried out under UV irradiation at room temperature, and showed ‘living’ polymerization nature which was evidenced by: linear evolution of molecular weight with conversion; and narrow molecular weight distribution (M_w/M_n = 1.08–1.20). The compositional analysis and the sequence structural information of the copolymer obtained from Distortionless Enhancement by Polarization Transfer (DEPT) NMR experiments demonstrated that the copolymers obtained possess strictly alternating structure. © 2003 Society of Chemical Industry     

Synergistic effect of dual rubber system in toughening styrene maleic anhydride copolymers

Styrene maleic anhydride (SMA) copolymers were toughened by blending with two distinctly different rubber modifiers: styrene‐butadiene‐styrene (SBS) block copolymer and methacrylated butadiene‐styrene emulsion‐made graft copolymer (MBS). The modifiers were used both individually and in combination for the examination of their roles in toughening SMA. SMA was miscible with poly(methylmethacrylate) shell of MBS, whereas it was partially miscible with the polystyrene (PS) phase of SBS. When 40–50% of SBS was used in blends, the PS phase of SBS became immiscible with SMA. SBS did not improve the Izod impact strength of SMA appreciably. A prominent synergistic toughening effect was experimentally observed when SBS and MBS were used in combination in brittle SMA. This effect may be attributed to the fact that the large SBS particles initiate crazes and small MBS particles with good adhesion to SMA matrix improve the ligament thickness, which may play a critical role in craze growth and termination. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2260–2267, 2003     

Study on kinetics of copolymerization of styrene and maleic anhydride in methyl ethyl ketone

The compositional and rate data are measured for the alternating copolymerization of styrene and maleic anhydride in methyl ethyl ketone at 60°C with AIBN as initiator. The kinetic scheme is evaluated in terms of the participation of a monomer-monomer complex, accepting that the monomer radical at the chain end reacts only with the dissimilar monomer of the complex. r₁ and r₂ are determined for vanishing complex concentrations. r₂ is very low but not zero. The ratios of propagation via the complex to those of normal alternating propagation could be evaluated as well as the term 2?δ₁δ₂r₁r₂. The latter only for vanishing [M₁] or [M₂] respectively and for [M₁] = [M₂]. This allowed us to calculate the rate vs. composition curve for three constant overall monomer concentrations. For the lowest overall concentration the agreement between calculation and experiment is only fair, but for the overall concentrations [M₁] + [M₂] = 1 and 3 mol 1^?1 it is good, thus demonstrating the possibility of describing the polymerization process by the model used here. The concept of participation of charge transfer complex between styrene an maleic anhydride is found to explain most features of copolymerization of these monomers in methyl ethyl ketone.     

Copolymerization of styrene and maleic anhydride in supercritical carbon dioxide

The copolymerization of styrene (St) and maleic anhydride (MA) was carried out in supercritical carbon dioxide (SC CO₂). It was found that St and MA are easy to copolymerize in SC CO₂ and the conversion can reach 97%, and that very fine and dry powders are obtained. The products were characterized using Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). GPC data showed that the molecular weight of the copolymer reach 3.62 × 10⁴ g mol^?1. Scanning electron microphotographs showed the minimum particle size of the product is about 200 nm. DSC measurements indicated that the glass transition temperature (T_g) of the copolymer increases with increasing the MA content in the copolymer. TGA curve showed that the copolymers were decomposed at about 350°C. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

阳离子改性苯乙烯-马来酸酐共聚物的制备与表征及应用

以2,3-环氧丙基三甲基氯化铵(ETA)为阳离子化试剂,对苯乙烯-马来酸酐共聚物(SMA)进行阳离子化改性,制备出一种阳离子性高分子分散剂(SMG)。通过红外光谱、含氮量、表面张力以及溶解性等的测定,研究了SMG的结构与性质;通过对颜料黄14的分散性考察,研究了SMG的分散性能。结果表明,SMA在阳离子化过程中,酸酐基团全部开环,部分形成酯键,阳离子化度达到7.5%左右;SMG的表面活性较低,但对颜料黄14的分散稳定性较好,在pH=7.0条件下,可以使颜料的Zeta电位提高至 35.4 mV。     

SMA工业生产计量及分析方法

运用密度法建立了可用于苯乙烯－马来酸酐共聚物（SMA）工业生产听密度－温度－浓度关系式。应用表明，此式在工业生产计量仪表的标定中是可信和可靠的。利用工业生产获得了有关工艺参数，还建立了针对SMA生产的反应器方程式。经20d连续工业生产考察表明，用反应器方式式所预测的转化率与实际值非常吻合，该方程式具有指导SMA工业生产的意义。     

Preparation and characterization of nano‐CaCO3 encapsulated by copolymerization of styrene and maleic anhydride

Encapsulated nanometer calcium carbonate (nano‐CaCO₃) was prepared using styrene and maleic anhydride (MAH) copolymer in 2‐propanol or methanol–water mixture in the presence of different initiator systems. The particle morphology and physical properties of the encapsulated nano‐CaCO₃ particles, such as the interaction between the encapsulating polymer and the nano‐CaCO₃, and the thermal stability of encapsulated nano‐CaCO₃ were studied by Fourier‐transform infrared spectroscopy (FTIR), Soxhlet extraction experiments, thermogravimetric analysis banded with FTIR (TGA‐FTIR) and transmission electron microscopy (TEM). The encapsulating ratio and the stable encapsulating ratio of encapsulated nano‐CaCO₃ were characterized. The results showed that a strong interfacial interaction was obtained due to the formation of a chemical bond or ion‐dipole between the C?O group of MAH and Ca²⁺ ion of nano‐CaCO₃. The encapsulating ratio and stable encapsulating ratio of nano‐CaCO₃ initiated by AIBN was higher than that initiated by BPO. Addition of maleic anhydride increased the encapsulating ratio and the stable encapsulating ratio of encapsulated nano‐CaCO₃. For the encapsulated nano‐CaCO₃ prepared in methanol–water, the diameter of the encapsulated nano‐CaCO₃ particle increased from 60–70 nm to about 100 nm and the morphology changed from a cube with a sharp edge to spherical with a rough surface. Copyright © 2006 Society of Chemical Industry     

Microwave radiation copolymerization in solid state of maleic anhydride and allylthiourea

Microwave radiation copolymerization of maleic anhydride and allylthiourea was studied in solid state. Composition of the monomer feed and the power and time of microwave radiation on conversion and intrinsic viscosity were discussed. Reactivity ratios for maleic anhydride and allylthiourea were also determined. Values of r₁ and r₂ were 0.875 and 0.650 for maleic anhydride and allylthiourea, respectively. The copolymer can be used as soluble macromolecular complexing agents for metal ions. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1563–1566, 1998     

马来酸酐熔融接枝二元乙丙橡胶的研究

在转矩流变仪中,以过氧化二异丙苯(DCP)为引发剂,采用多单体熔融接枝技术,研究了二元乙丙橡胶(EPM)熔融接枝马来酸酐(MAH),考察了MAH含量、DCP用量、反应温度、反应时间、转子转速以及第二单体苯乙烯(St)的用量对接枝反应的影响,并用红外光谱(FTIR)对接枝产物进行了表征.研究结果表明:对于EPM-g-MAH体系,MAH和DCP最佳用量分别为3.0 phr和0.22 phr,最佳反应温度为170℃,反应时间8 min,转子转速60 r/min,此时接枝率最高达到0.46％;加入第二单体St后,当n(St) /n(MAH)为1/1时,EPM-g-(MAH-co-St)的接枝率为0.64％,接枝率明显提高.     

苯乙烯对马来酸酐熔融接枝聚丙烯的影响

用双螺杆挤出机分别制备了马来酸酐(MAH)和MAH-苯乙烯(St)共单体接枝共聚聚丙烯(PP)。红外光谱分析表明:MAH单体被接枝到PP大分子链上;引入St后,产物熔体流动速率从16.42 g/10min降为0.60 g/10 min;吸光度比从0.021升高到0.778,但St含量过高时,PP基体发生交联,影响接枝共聚物的加工性能。探讨了共单体St的作用机理以及交联机理。