高性能聚芳酯纤维的研制和表征

介绍了热致性液晶聚芳酯纤维的制备。选用双酚A、对苯二甲酸、间苯二甲酸为单体进行熔融聚合,制得具有不同相对分子质量的双酚A-对/间苯二甲酸共聚酯,探索了后续固相聚合工艺,研究了后续固相聚合对原熔融聚合物相对分子质量、热性能以及力学性能的影响。原聚合物再经固相聚合及不经固相聚合的两种聚芳酯在不同的纺丝和热处理工艺条件下,可以获得力学性能相近的聚芳酯纤维,为进一步研制热致液晶型聚芳酯纤维生产路线提供可靠的工艺数据。     

共聚PET固相聚合粘度变化规律的研究

利用固相聚合生产装置,研究了共聚PET固相聚合反应温度、停留时间、氮气流量、催化剂含量、基础切片端羧基含量对增粘的影响。结果表明:在一定的工艺条件下,产品粘度随反应温度提高、停留时间的延长及催化剂含量的增大而增大;当气固比大于0.3时,增大氮气流量对增粘速率不再产生影响。     

固相聚合PET及饮料瓶的热性能研究

应用 DSC、 TGA和 TMA研究了固相聚合 PET树脂的双重熔融行为、热稳定性及瓶坯、包装瓶的结晶性能和膨胀性。结果表明 ,固相聚合 PET树脂在不同升温速度下的双重熔融行为反映出树脂结晶结构的完整性 ,可为确定固相聚合生产的工艺条件提供参考。对具有不同结晶性能和热稳定性的固相聚合 PET树脂 ,其制坯及吹瓶工艺条件应作必要调整。     

聚合物用热处理装置

瑞士Ｂｉｕｌａｒ机械制造公司开发的聚合物用热处理装置不但能进行干燥，而且还可用作固相聚合。     

新型生物降解材料——含氢键聚乳酸的制备

采用熔融固相聚合制备了乳酸-氨基酸共聚物，并用HNMR IR DSC GPC对共聚物进行了袁征。结果表明：熔融聚合的最佳工艺条件为，催化剂辛酸亚锡用量为0．5％-1％、聚合时间为10h、氨基酸含量为0．5％-1％；固相聚合的工艺条件为，聚合时间20h、催化剂为辛酸亚锡。此工艺条件可制得分子量大于50000的共聚物。     

尼龙6固相聚合的计算机模拟(英文)

建立了尼龙 6固相聚合过程动力学模型 ,并用实验数据进行了验证。考查了模型参数对固相聚合尼龙 6聚合度和多分散性指数的影响 ,分析固相聚合过程诸多的影响因素对尼龙 6聚合度及多分散性指数的影响。利用此模型 ,分析了固相聚合一定时间后水浓度、数均聚合度在颗粒半径方向上的分布     

磷酸二氢钾盐对热致液晶聚合物的合成与性能影响研究

以对羟基苯甲酸、联苯二酚、对苯二甲酸、间苯二甲酸为单体,分别以醋酸酐和乙酸镁为酰化剂和催化剂,并在合成过程中添加0.000%～0.030%(基于单体总质量)磷酸二氢钾盐(KH2PO4),采用预聚合-固相聚合工艺制备热致液晶聚合物(TLCP)。研究了KH2PO4添加量对预聚合、固相聚合工艺以及所得树脂热性能、色泽和力学性能的影响。结果表明:磷酸二氢钾对预聚合与固相聚合有催化作用,TLCP树脂的熔融温度随磷酸二氢钾添加量的增加而提高,当添加0.025%的KH2PO4合成的树脂色泽以及力学综合性能最优。     

聚2,6-萘二甲酸乙二酯的合成及固相聚合

采用生产 PET的工艺路线和设备生产聚 2 ,6 -萘二甲酸乙二酯 ( PEN)。讨论了酯化反应 ,熔融聚合 ,固相聚合阶段的工艺条件。通过固相聚合后 ,PEN切片的特性粘数可由熔融聚合的 0 .5 d L/g提高到 0 .7d L /g以上     

PBT的固相增黏研究

通过对PBT固相增黏反应条件:温度、真空度、反应时间的改变,检测PBT固相扩链反应物的流动速率,比较不同反应条件下的固相聚合增黏效果,总结了工艺参数对固相聚合反应的影响。并且通过红外谱图,DSC谱图分析了增黏反应对PBT树脂分子结构、结晶情况以及熔点的影响。     

超高分子量PET的固相聚合

本文采用分段固相聚合的方法合成了特性粘度达1.5以上的超高分子量PET树脂。研究了聚合温度、聚合时间、聚合体颗粒度、搅拌速度、真空度等对固相聚合速度的影响,初步探讨了固相聚合机理,确立了较佳的工艺路线,为纺制高强PET纤维打下了基础。     

PET固相缩聚工艺技术分析

综述了聚酯(PET)固相缩聚过程特点,重点对比分析了Bepex、Buhler、Sinco及Dupont的NG3连续固相缩聚工艺、关键设备构型及主要操作参数。PET固相缩聚过程中结晶增长与缩聚反应共存并互相耦合,因而结晶工序是固相缩聚工艺的重要组成部分,也是各工艺专利商的专利技术之所在。有效的结晶增长、结晶形态与缩聚反应的解耦合是强化固相缩聚技术的科学基础。     

Radiation-induced solid state polymerization

The literature on radiation-induced solid state polymerization has been increasing exponentially in the last five years. Major advances have been made in retention of crystalline morphology during polymerization, in stereospecific polymerization, in modification of reactivity ratios in copolymerization and in molecular weight control of the product. However, at the present time, no commercial products have resulted from the study of radiation-induced solid state polymerization. Chemically induced polymerization techniques have been keeping abreast of this explosive development in the solid state polymerization field and have up to this time precluded the use in industry of solid state polymerization. The major potential at the present time appears to be in the area of producing fibers without additional processing.     

Solid‐state polymerization of bisphenol A polycarbonate with a spray‐crystallizing method

A novel crystallization method for the production of high‐molecular‐weight bisphenol A polycarbonate by solid‐state polymerization is suggested. In this method, a low‐molecular‐weight polycarbonate prepolymer is dissolved in a solvent and then partially crystallized with a novel spray‐crystallizing method to prepare crystallized polycarbonate particles having a very uniform and porous structure with a narrow melting region. As a result, during solid‐state polymerization, the phenol byproduct can be easily removed from the polymerizing porous polycarbonate particles, and the polymerization rate is dramatically increased. In particular, the effects of the crystallization methods on secondary crystallization during solid‐state polymerization and the melting behavior have been investigated with differential scanning calorimetry studies. The final product, a high‐molecular‐weight polycarbonate, displays a very narrow molecular weight distribution and uniform physical properties. A simultaneous process and an adequate reactor design for spray crystallization and solid‐state polymerization are also suggested. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

N_2对PET连续固相缩聚生产的影响探讨

结合生产试验结果 ,分析、研究N2 流量、温度及其组分对PET固相缩聚反应速率及产品质量的影响 ,用于指导生产 ,优化调整工艺 ,提高瓶用聚酯的产品质量。     

Rapid solid‐state photopolymerization of octadecyl acrylate: low shrinkage and insensitivity to oxygen

Mobility restrictions in solid‐state photopolymerization give extremely poor polymerization kinetics, but octadecyl acrylate can be rapidly photopolymerized in the solid state. The XRD, real‐time Fourier transform IR and DSC analyses prove that the hexagonal packing of monomer molecules is favorable for UV‐initiated solid‐state polymerization, and crystalline long alkyl chains of monomers were preserved as the crystalline long alkyl side‐chains of polymers. More importantly, octadecyl acrylate provides a chance to investigate the shrinkage and oxygen inhibition of UV‐induced solid‐state polymerization. This novel radical‐mediated solid‐state photopolymerization is insensitive to oxygen and lowers the volume shrinkage (1.48%). © 2013 Society of Chemical Industry     

双酚A聚碳酸酯合成新方法的研究进展

介绍了双酚A聚碳酸酯不同于工业生产中常用的光气法和熔融酯交换法的3种新的合成方法,即固相缩聚法、开环聚合法、完全非光气法的实施方法、主要特点及其新进展,探讨了各种方法存在的主要问题以及对生成的聚合物结构和性能的影响。固相缩聚是由预聚物结晶后在固相缩聚,可以获得结晶型双酚A聚碳酸酯并提高聚合物质量;开环聚合法首先合成环状碳酸酯低聚物再开环聚合得到聚合物,可以获得很高分子质量聚合物;完全非光气法在合成过程中完全避免了光气的使用,环境友好,聚合物质量高,很有发展前景。     

丁二烯聚合因素分析及预防措施

丁二烯聚合是影响装置运行质量的关键因素。分析了影响丁二烯聚合的因素，提出了通过控制系统中的氧及铁锈、减少设备管线死角、按量按点注入阻聚剂、采用新型阻聚剂和严格控制工艺操作条件等方法预防丁二烯聚合，保证装置的长周期运行，保证产品质量，杜绝安全事故的发生。     

Solid‐state modification of isotactic polypropylene (iPP) via grafting of styrene. II. Morphology and melt processing

Grafting of vinyl monomers onto isotactic polypropylene (iPP) in the solid state represents a convenient route to chemically modify iPP and, consequently, its properties. Solid‐state modification can be carried out on iPP powder directly from the polymerization reactor. The modified powder is then processed in the melt, usually with the addition of fillers and/or additives, to obtain the final product. In this work we have studied the effect of melt processing on the morphology of solid‐state polymerized PP/polystyrene (PS) blends, i.e., of a iPP powder previously modified in the solid‐state with styrene (St) and optionally in the presence of divinylbenzene (DVB). A series of samples containing different amounts of PS and displaying different grafting efficiencies were investigated before and after processing in the melt. Transmission electron microscopy, scanning electron microscopy, and solid‐state NMR were used to investigate the morphology on different length scales. It was shown that PS coalescence during processing can be hindered, thereby stabilizing the initially polymerized iPP/PS blends morphology. Indeed, reducing the PS amount in the blend or increasing the grafting efficiency resulted in less coalescence of the PS domains. Crosslinking of the PS phase during the solid‐state polymerization resulted also in a very fine but heterogeneous morphology. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 575–583, 2005     

Modeling and simulation of a continuous biomass hydrothermal carbonization process

Abstract

This work evaluates a continuous biomass hydrothermal carbonization process through modeling and steady state simulation using the UniSim Design process simulator. The reactive process was divided into four stages: biomass hydrolysis, intermediate compounds degradation, aromatics formation, and polymerization process, which make it possible to obtain the solid product or hydrochar. Pure biomass types and their mixtures were compared, considering hydrochar and carbon yields, H/C, and O/C ratios, and their deviation from the batch process. The results of hydrochar yield indicated that biomass with high cellulose content can perform satisfactorily in the proposed model. In addition, the possibility of carrying out the process in reactive stages together with the recirculation of liquid product, allowed a greater yield with respect to the batch process. It is concluded that the proposed model improves the characteristics of the obtained hydrochar compared to its crude biomass, achieving lower proportions of hydrogen and oxygen in the solid product.     

Radiation-induced solid-state polymerization in binary systems. VII. Polymerization in solid–liquid equilibrium phase containing long-chain compounds

The radiation-induced polymerization of binary systems consisting of vinyl monomers (mainly methyl methacrylate) and various long-chain compounds in solid–liquid equilibrium state has been studied. Phase diagrams of these systems showed that all systems containing long-chain compounds form a complete crystalline phase at temperatures below the solidus line. It was found that remarkable acceleration of the polymerization occurred in the solid–liquid equilibrium state. The long-chain compounds are classified into three groups according to the acceleration effect. The group including paraffin, long-chain esters, and cetyl alcohol exerted the largest acceleration effect over wide temperature regions at which the solid–liquid equilibrium exists. Maximum polymerization rate was observed at temperatures below the melting point in the presence of long-chain compounds of the above-mentioned group. It was observed in this case that the long-chain compounds crystallized to form very fine colloidal particles and the system was soft and waxy in the solid–liquid equilibrium state. The acceleration of the polymerization in the binary system consisting of a vinyl monomer and a compound having no long-chain substituents or in the homogeneous solution consisting of monomer and viscous solvent were far less than that in the presence of long-chain compounds. It is suggested that the effect can be attributed to the effect of a special reaction matrix favorable to polymerization in the solid–liquid equilibrium.