原位缩聚合成含聚芳酰胺／酯的微相复合物 Ⅴ．共聚酰胺与聚砜的微相复合物制备

用原位缩聚法合成了芳香-脂肪共聚酰胺与聚砜的徽相复合物(PAA／PSF)。初步结果表明:PAA／PSF微相复合物具有热致液晶性能;PAA的加入大大提高了微相复合物的力学性能。以PA30(PAA=29．5ω)为例,拉伸强度和模量分别提高到原来的2．5倍和3．5倍。     

原位缩聚合成含聚芳酰胺/酯的微相复合材料Ⅳ.全芳香聚酰胺与聚砜的微相复合材料制备

以原位缩聚方法合成了PPTA/PSF的微相复合材料。FTIR、DSC等分析结果表明,PPTA/PSF微相复合材料较PPTA/PBT-PTMG分子链间存在着更强的相互作用,PPTA对基体聚合物的力学性能有较大的提高。初步结果表明,加入第三单体双酚A在一定程度上提高了复合材料的抗张强度和断裂伸长率,但是模量有所下降。     

原位缩聚合成含聚芳酰胺/酯的分子复合材料Ⅰ分子复合材料的研究进展

高分子复合材料是指两种或两种以上物理和化学性质不同的高分子所组成的多相固体材料,是能够将各组分的优点有机结合起来,并表现某些新的有用特性的材料体系。近年来有关刚性棒状高分子与柔性基体聚合物的复合与研究非常活跃,但是,由于刚性棒状高分子与柔性基体存在着在热力学上的不相容性,使两组分达到分子水平的分散相当困难;而且由于刚性棒状高分子难溶难熔,因此更难于用溶液共混或螺杆挤出共混的方法制备分子复合材料。因此改进刚性高分子与柔性链聚合物基体的混溶性是多相高分子体系的一个重要课题。文章综述并讨论了分子复合材料的研究进展以及各种合成技术。     

原位缩聚合成含聚芳酰胺／酯的微相复合物 Ⅲ．全芳聚酰胺与聚酯-聚醚体系的研究

对于聚对苯二甲酰对苯二胺(PPTA)和PBT-PTMG体系,比较了溶剂配比(CH2Cl2／NMP)、聚合物浓度、强极性溶剂的用量和加料方式对缩聚反应的影响。发现溶剂配比、基体聚合物PBT-PTMG影响PPTA的转化率和PPTA的分子质量。通过FTIR研究发现PPTA中的酰胺键-NH-和PBT-PTMG的醚键特征吸收均向低渡数位移;通过用PBT-PTMG 的良溶剂二氯甲烷对复合物进行产抽提,结果发现,刚性链PPTA与PBT-PTMG分子链有较强的氢键相互作用,从而改进了分子间的相容性,获得了PPTA／PBT-PTMG的微相复合物。PPTA／PBT-PTMG的微相复合物有较好的力学性能。     

原位缩聚合成含聚芳酰胺/酯的微相复合材料Ⅱ.基体聚合物溶剂对微相复合材料形态与性能的影响

通过研究对羟基苯甲酸(HB)在基体聚合物聚对苯二甲酸丁二醇酯-聚四亚甲基醚多嵌段共聚物(PBT-PTMG) 的溶液中原位缩聚制备微相复合材料过程中所用溶剂的影响,研究基体聚合物溶剂对微相复合材料形态与性能的影响。     

多元共缩聚半芳香透明聚酰胺的热性能研究

利用差示扫描量热仪(DSC)、热重分析仪(TG)和动态热机械分析仪(DMA)测试了多元共缩聚半芳香透明聚酰胺的热性能,对其耐热性和热稳定性进行了分析讨论。实验结果表明:随着半芳香组分的增多,分子链中引入了更多的刚性基团,导致分子链段的活动能力下降,玻璃化转变温度Tg提高;共缩聚半芳香透明聚酰胺的热降解过程为一步降解,热降解温度均在440℃以上,表明该半芳香透明聚酰胺具有优异的热稳定性;在低温下有明显的γ转变峰,表明该半芳香透明聚酰胺在低温下有较好的韧性。     

固相缩聚半芳香透明聚酰胺的流变性能

采用毛细管流变仪对固相缩聚半芳香透明聚酰胺(Semi-AromaticTransparent Polyamide,简称SATPA)的流变性能进行了研究。研究结果表明:固相缩聚SATPA熔体属假塑性流体,非牛顿指数随剪切速率的增大而减小;表观黏度随温度、剪切速率和剪切应力的升高而降低。随着剪切速率的增大,黏流活化能减小,表观黏度对于温度的敏感性减弱。     

微纳层叠共挤PP/PA6/CNTs原位微纤复合膜的制备及性能研究

采用双转子连续混炼挤出机与微纳层叠共挤出成型设备制备了聚丙烯/聚酰胺6/碳纳米管（PP/PA6/CNTs）复合材料和原位微纤复合膜,通过扫描电子显微镜（SEM）、流变仪、差示扫描量热仪（DSC）、万能拉伸试验机及电阻测试仪对其微观结构、流变性能、结晶性能、力学性能和导电性能进行了表征。结果表明,与共混相比,微纳层叠共挤出法使得分散相PA6/CNTs形成了微纤,微纤的形成不仅提升了复合膜的动态流变性能,并且增加了基体PP相的结晶度,提高了PA6相的结晶温度,提升了复合膜的结晶性能;当CNTs含量为0.5 %（质量分数,下同）时,复合膜的拉伸强度和断裂伸长率均达到最大值,分别为42.17 MPa和857.82 %,体积电阻率（R）下降到10⁴ Ω·cm,综合力学性能和导电性能达到最佳。     

新型半芳香共聚酰胺PA10T/10Py的制备及性能表征

采用两种结构相近的半芳香酰胺对苯二甲酰癸二胺(10T)和2,5吡啶二甲酰癸二胺(10Py)盐,通过成盐、预聚合、固相后聚合“三步法”制得一种新型半芳香共聚酰胺PA10T/10Py,采用相对黏度、傅立叶变换红外吸收光谱仪(FTIR)、差示扫描量热仪(DSC)、热重分析仪(TG)和X射线衍射仪(XRD)等表征手段对其结构性能进行分析。结果表明,共聚酰胺中酰胺键的红外吸收峰峰位相比于均聚半芳香聚酰胺PA10T变高。PA10Py的加入降低了半芳香聚酰胺材料的熔点,并维持了较高的热分解温度,初始分解温度在390℃以上。同时也提高聚酰胺材料的机械性能,相比对不添加PA10Py的样品,拉伸强度可提高16%。吡啶环结构的定量加入为制备具有良好加工性能和机械性能的半芳香聚酰胺材料提供了一种新的技术路线。     

共聚酰胺6/66的合成与表征

采用己内酰胺和己二酸己二胺盐等为原料合成系列共聚酰胺6/66,研究了共聚单体配比、开环剂及相对分子质量调节剂对共聚物性能的影响。通过傅里叶变换红外光谱、核磁共振氢谱、X射线衍射和差示扫描量热仪分别对共聚物的结构与热性能进行了测试。结果表明:己二酸己二胺盐和ε-氨基己酸对共聚反应不仅具有一定的促进作用,还降低了共聚物的可萃取物含量;己二酸己二胺盐的加入并未改变主体聚酰胺6的晶型结构,均为稳定的α晶型;共聚酰胺6/66的熔融双峰是由于晶体结构的重组导致的。     

Surface modification of polysulfone membranes by low‐temperature plasma–graft poly(ethylene glycol) onto polysulfone membranes

A novel and general method of modifying hydrophobic polysulfone (PSF) to produce highly hydrophilic surfaces was developed. This method is the low‐temperature plasma technique. Graft polymer‐modified surfaces were characterized with the help of Fourier transform infrared attenuated total reflection (FTIR–ATR) and X‐ray photoelectron spectroscopy (XPS). Study results demonstrated that poly(ethylene glycol) (PEG) could be grafted onto the PSF membrane surface by low‐temperature plasma. The hydrophilic character of the modified surfaces was increased in comparison with that of the parent membrane. The contact angle for a modified PSF membrane was reduced apparently. We analyzed the effectiveness of this approach as a function of plasma operating variables including plasma treatment power and treatment time. Hence, plasma‐induced graft polymer modification of membranes can be used to adjust membrane performance by simultaneously controlling the surface hydrophilicity and hemocompatibility. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 979–985, 2000     

原位乳液聚合聚苯胺/聚甲基丙烯酸甲酯复合物及其表征

以DBSA为乳化剂和掺杂剂,在水介质中采用原位乳液聚合法制备出了聚苯胺/聚甲基丙烯酸甲酯(PANI/PMMA)复合物。采用扫描电镜、红外光谱分析、紫外光谱分析、热失重分析、X射线光电子能谱分析对PANI/PMMA复合物进行了表征。结果表明:复合物产物粒径在80～120nm;电导率可达到10-2S/cm,接近于乳液聚合得到的DBSA掺杂态PANI;乳化剂DBSA以掺杂剂和稳定剂两种状态存在于复合物中。     

直接缩聚合成聚乳酸研究进展

聚乳酸是一种性能优良的完全生物降解塑料,产品价格高是其进入市场的重要障碍,通过直接缩聚法有望能合成低 成本的聚乳酸。综述了溶液缩聚及直接熔融缩聚、熔融缩聚-扩链、熔融缩聚-固相聚合合成聚乳酸的研究进展。展望了直接 缩聚法合成聚乳酸的前景。     

Synthesis of poly(alkylene succinate) biodegradable polyesters, Part II: Mathematical modelling of the polycondensation reaction

In this investigation, synthesis of three biodegradable aliphatic polyesters, namely poly(ethylene succinate) (PESu), poly(propylene succinate) (PPSu) and poly(butylene succinate) (PBSu), is presented using the appropriate diols and succinic acid in the presence of tetrabutoxytitanium as catalyst. A theoretical mathematical model for the polycondensation reaction is developed and applied successfully in the simulation of all experimental data. From measurements of intrinsic viscosity (IV) at four polycondensation temperatures (210, 220, 230 and 245 °C) and different times from 15 min to 3 h, it was concluded that PESu exhibits higher values followed by PBSu and finally PPSu. Using additional measurements on the carboxyl content and the simulation model results, it was found that when ethylene glycol is used as reactant, both esterification and transesterification reaction rates are promoted resulting thus in lower carboxyl concentrations and higher IV values. However, the transesterification reaction rate constant of PPSu is much lower compared to PBSu leading to higher carboxyl and hydroxyl end groups and therefore finally lower IV values. Moreover, the esterification rate constant was estimated always to be much larger compared to the rate constant of the transesterification reaction, meaning that the former reaction proceeds much faster compared to the later, resulting thus in very low values of the carboxyl end groups compared to corresponding hydroxyl end groups. Finally, from measurements of the mechanical properties of the polyesters produced it was found that concerning the tensile strength and the elongation at break, PBSu exhibits the larger values followed by PESu in the order: PBSu > PESu > PPSu, whereas PESu exhibits higher Young's Modulus in the order: PESu > PBSu > PPSu.     

Synthesis of novel optically active poly(ester imide)s by direct polycondensation reaction promoted by tosyl chloride in pyridine in the presence of N,N‐dimethyformamide

4,4′‐Hexafluoroisopropylidene‐2,2‐bis(phthalic acid anhydride) (1) was treated with L ‐methionine (2) in acetic acid and the resulting 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐methionine) diacid (4) was obtained in high yields. The direct polycondensation reaction of this diacid with several aromatic diols, such as bisphenol A (5a), phenolphthalein (5b), 1,4‐dihydroxybenzene (5c), 4,4′‐dihydroxydiphenyl sulfide (5 d), 4,6‐dihydroxypyrimidine (5e), 4,4′‐dihydroxydiphenyl sulfone (5f), and 2,4′‐dihydroxyacetophenone (5g), was carried out in a system of tosyl chloride (TsCl), pyridine (Py), and N,N‐dimethylformamide (DMF). The reactions with TsCl were significantly promoted by controlling alcoholysis with diols, in the presence of catalytic amounts of DMF, to give a series of optically active poly(ester imide)s, (PEI)s, with good yield and moderate inherent viscosity ranging from 0.43 to 0.67 dL/g. The polycondensation reactions were significantly affected by the amounts of DMF, molar concentration of monomers, TsCl and Py, aging time, temperature, and reaction time. All of the aforementioned polymers were fully characterized by ¹H NMR, FTIR, elemental analysis, and specific rotation. Some structural characterization and physical properties of these optically active PEIs are reported. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 455–460, 2006     

Diameter control of poly(p-oxycinnamoyl) microspheres prepared by self-organizing polycondensation

The diameter control of poly(p-oxycinnamoyl) (POC) microspheres was examined. POC microspheres were prepared by the polycondensation of (E)-4-acetoxycinnamic acid in liquid paraffin at 320 °C. The microspheres were formed through the formation of microdroplets by the reaction-induced liquid-liquid phase separation and the subsequent polymerization of oligomers in the microdroplets leading to the solidification. The size of the microspheres was actually governed by the coalescence of the microdroplets in the growth process. In order to control the coalescence of the microdroplets, 4-octadecyloxybiphenyl (ODB) was added to the polymerization solution as a coalescence inhibitor, which exhibited amphiphilicity to liquid paraffin and POC. ODB inhibited the coalescence of the microdroplets. The average diameter decreased with the increase of the ODB concentration, and it was tunable from 0.97 to 4.61 μm.     

Synthesis and characterization of aqueous (polyurethane/aromatic polyamide sulfone) copolymer dispersions from castor oil

Aqueous dispersions of castor oil-based polyurethane (PUCO)/aromatic polyamide sulfone (APAS) block copolymers (PUCO-co-APAS) were successfully synthesized via a copolymerization reaction. PUCO was prepared by an emulsion polymerization process in four steps, namely isocyanate-terminated prepolymer preparation step (PUCO_NCO), neutralization step, chain extension step and dispersion step, using castor oil (CO), toluene diisocyanate (TDI), dimethylol propionic acid (DMPA) and ethylene diamine (EDA) as a chain extender. APAS was prepared by a polycondensation reaction between bis(4-aminophenyl)sulfone (in molar excess) and terephthaloyl chloride to produce amino-terminated APAS. Three PUCO-co-APAS were prepared via a copolymerization reaction between the amino-terminated APAS and isocyanate-terminated PUCO_NCO prepolymer. APAS, PUCO and PUCO-co-APAS copolymers were characterized using FTIR, ¹H NMR, particle size distribution (PSD), zeta potential (ZP), thermal analysis (DSC and TGA) and GPC. The effect of the copolymerization process on the thermal, chemical, physical and mechanical properties of PUCO films was studied. The obtained results revealed that the mean particle size of PUCO decreased from 80 nm to 46–49 nm after the copolymerization process. Additionally, narrower size distribution was obtained by the copolymerization process. However, the molecular weight increased with increasing the amount of APAS in the copolymer chains. The copolymerized samples showed better thermal stability than PUCO as a result of the stronger hydrogen bonds and the rigid aromatic groups introduced by APAS in the copolymeric chains.