羧酸型离聚体的研究进展

综述了羧酸型离聚体的合成、链结构和聚集体结构,和由其结构引起的特殊力学性能和溶液性质;介绍了羧酸型离聚体在共混物增容、包装材料及纳米复合材料等方面的应用及其发展。     

CPVC羧酸型离聚体的合成以及性能研究

采用氯化原位接枝制备的氯化聚氯乙烯接枝丙烯酸(CPVC-g-AA)与Al(OH)3中和,制备羧酸型离聚体.将离聚体纯化后进行傅立叶变换红外光谱(FT-IR)和差示扫描量热仪(DSC)分析,并进行动态机械分析(DMA)测试,讨论了离聚体力学性能和溶胀性能.结果表明,FT-IR谱图显示出现了新的离子特征吸收峰;离聚体的玻璃化转变温度比CPVC-g-AA的有很大提高;Al离子含量和中和度对离聚体的力学性能具有较大影响;Al离子含量高时,离聚体表现出溶胀行为.     

离聚体的制备及抗静电研究

乙烯丙烯酸共聚物(EAA)在熔融中和反应下形成离子聚合物,首先测试了不同中和度的钾离聚体的流变性能和抗静电性能,另外测试了K、Na、Mg、Zn四种离子中和两种EAA而得的离聚体抗静电的效果,并讨论了两种羧酸含量的EAA按不同比例复配、中和后对抗静电性能的影响。结果发现,钾离聚体的抗静电性能最为优异,中和度为80%的EAA 5200钾离聚体,其表面电阻率可达2.53×10~9Ω,但是由于原料中羧酸含量较低,复配效果不明显。在表征了不同离子的离聚体吸水能力后,发现钾离聚体的吸水能力和稳定性最高,其平衡吸水率可达20.19%。     

高乙烯基聚丁二烯橡胶双羧酸型钠离聚体的阻尼性能

将高乙烯基聚丁二烯橡胶(HVBR)与马来酸酐接枝改性后,与氢氧化钠络合制备了HVBR双羧酸型钠离聚体。结果表明,HVBR接枝共聚物断裂表面出现许多裂痕,在动态力学性能测试中发生断裂,而HVBR钠离聚体断裂表面出现许多相连的凸起结构。与HVBR相比,HVBR钠离聚体具有较好的抗湿滑性、低生热和低滚动阻力,拓宽了有效阻尼温域,更接近于室温。     

烯烃复分解法制备高乙烯基聚丁二烯离聚体及其结构和性能

以甲基丙烯酸乙酯(EMA)为改性单体,采用交叉烯烃复分解法对高乙烯基聚丁二烯(HVBR)酯基官能化改性。研究了烯烃复分解催化剂种类和用量、EMA用量、反应条件等对改性HVBR的接枝率和黏均相对分子质量(M_v)的影响。研究表明,使用Hoveyda-Grubbs二代催化剂,催化剂与单体的质量比为1.5×10^-4,EMA与HVBR的质量比为1时,产物接枝率最高。烯烃复分解反应优先与HVBR的侧乙烯基双键反应。采用溶液法酯基官能化改性后的HVBR与NaOH反应可制备HVBR羧酸钠离聚体。离聚体的拉伸强度与HVBR相当,扯断伸长率提高了50%,撕裂强度提高了30%,力学性能得到显著改善。硫化胶的动态机械性能分析仪(DMA)数据显示,HVBR羧酸型离聚体的阻尼温域均变宽,提高了20%以上,是一种良好的宽温域阻尼材料;离聚体具有高抗湿滑和低滚阻,可以用于绿色轮胎制造。     

中和度对EAA-Na离聚体及EAA-K离聚体结晶形态的影响

通过熔融中和反应,分别制备了Na OH及KOH中和乙烯-丙烯酸共聚物(EAA)离聚体(记作EAANa离聚体,EAA-K离聚体)。利用偏光显微镜、广角X射线衍射仪研究了EAA-Na离聚体、EAA-K离聚体中和度对其结晶形态的影响。结果表明:EAA中引入Na+和K+后,离聚体结晶度降低,而且在中和度较高的情况下,在离聚体内部可观察到一些未反应的颗粒,尤其是EAA-K离聚体内部出现了更多的堆积颗粒;EAA-Na离聚体的结晶度比EAA-K离聚体高,且其晶粒尺寸比EAA-K离聚体小。     

弹性离聚体的研究进展

总结及评述了近年来弹性离聚体的研究进展,包括羧基离聚体、磺化离聚体及遥爪离聚体等,介绍了最近用新方法合成的新型离聚体.     

磺酸钠基苯乙烯-丁二烯-苯乙烯嵌段共聚物离聚体的力学性能及其应用

由环氧化苯乙烯-丁二烯-苯乙烯嵌段共聚物(SBS)与NaHSO3开环反应合成了磺酸钠基SBS离聚体。研究了离聚体力学性能的影响因素、离聚体对SBS/氯醇橡胶(CHR)的增容作用、质量比对离聚体/聚丙烯(PP)共混物性能的影响。结果表明:硬脂酸锌能提高离聚体的力学性能;随着离聚体离子含量的增加,拉伸强度及扯断伸长率增加。加入少量离聚体,使离聚体/CHR共混物的力学性能提高,扫描电镜显示两者的相容性增加;离聚体与PP共混,在拉伸强度方面呈现协同效应。质量比各为1/1的离聚体增容SBS/CHR和离聚体/PP共混物的耐油性均较SBS大为改善。     

顺丁烯二酸钾基(苯乙烯-丁二烯-苯乙烯)嵌段共聚物离聚体的力学性能及其应用

用环氧化(苯乙烯-丁二烯-苯乙烯)嵌段共聚物(SBS)开环反应合成了含顺丁烯二酸钾基的SBS离聚体,考察了离子基团不同含量对含顺丁烯二酸钾基的SBS离聚体力学性能的影响,研究了离聚体/聚丙烯(PP)共混物的力学性能和耐溶剂性能,以及离聚体对氯醇橡胶(CHR)/SBS共混物的增容效果。结果表明,该离聚体呈现热塑性弹性体行为;随着离子基团含量的增加,离聚体的拉伸强度及扯断伸长率增大,但当离子基团含量超过1.69mmol/g时,离聚体的力学性能又有所下降,离子基团最佳含量为1.23~1.69mmol/g;该离聚体与PP共混,在拉伸强度方面呈现协同效应;离聚体作为增容剂提高了SBS与CHR的相容性,当离聚体质量分数为3%时,力学性能达到最佳,共混物的耐溶剂性能也得到了改善。     

不同金属离子及胺中和的磺化丁基橡胶离聚体的性能

研究了不同金属离子及胺中和的磺化丁基橡胶离聚体的熔融流动性及力学性能。结果表明,随着硬脂酸锌加入量的增加,锂离聚体的熔融黏度降低,拉伸强度增大;随离聚体中磺酸基含量的增加,锂离聚体的熔融黏度和拉伸强度增大。对于一价金属离子中和的离聚体,其熔融黏度及拉伸强度随着离子电位的降低而减小;对于二价金属离子中和的离聚体,随着离子电位的下降及共价性的增加,熔融黏度下降而拉伸强度增大。用胺中和的离聚体,硬脂酸锌的影响较小,未加硬脂酸锌的离聚体具有较高的扯断伸长率及较低的永久变形,是良好的热塑性弹性体;随离聚体中磺酸基含量的增加,乙胺离聚体的拉伸强度增大。对于不同胺中和的离聚体,其拉伸强度按下列顺序依次降低：乙胺,三乙胺,二乙胺;乙胺,己胺,十二胺,十八胺。     

磺化丁苯橡胶离聚体与一些聚合物的熔融共混及产物性能

将磺化丁苯橡胶镁离子交联聚合体（简称离聚体）在增塑剂硬脂酸锌存在下分别与聚丙烯（ＰＰ）、高密度聚乙烯（ＨＤＰＥ）、丁苯嵌段共聚物（ＳＢＳ）、聚苯乙烯（ＰＳ）、顺丁橡胶（ＢＲ）在Ｂｒａｂｅｎｄｅｒ塑性仪密炼机中熔融共混，考察了共混比对平衡扭矩及物理机械性能的影响。结果表明，磺化丁苯橡胶镁离聚体与ＳＢＳ或ＰＰ共混，其拉伸强度呈协同效应，与ＨＤＰＥ共混呈加和效应，而与ＰＳ或ＢＲ共混则呈抵销效应。透射电镜     

磺化乙丙橡胶离聚物的研究进展

对磺化乙丙橡胶离聚物的研究作了简要回顾，介绍了磺化乙丙橡胶离聚物的制备方法，重点评述了在原料选择、反应条件、反应机理等方面取得的研究进展．并对磺化乙丙橡胶离聚物的性能及应用进行了简述。     

The control of miscibility of PP/EPDM blends by adding lonomers and applying dynamic vulcanization

The control of miscibility for isotactic polypropylene (PP) and ethylene-propylene-diene terpolymer (EPDM) has been attempted by adding poly(ethylene-comethacrylic acid) (EMA) ionomers and by applying dynamic vulcanization. The rheological properties, crystallization behavior, and morphology of the dynamically vulcanized EPDM/PP/ionomer ternary blends were investigated with a Rheometrics dynamic spectrometer (RDS), a differential scanning calorimeter (DSC), and a scanning electron microscope (SEM). Two kinds of EMA ionomers neutralized with different metal ions (Na⁺ and ZN⁺⁺) were investigated. Blends were prepared on a laboratory internal mixer at 190°C. Blending and curing were performed simultaneously, i.e., EPDM was vulcanized with dicumyl peroxide (DCP) in the presence of PP/ionomer. The composition of PP and EPDM was fixed at 50/50 by wt% and the contents of EMA ionomer were vaired from 5 to 20 parts based on the total amount of PP and EPDM. It was found that the addition of ionomers and the application of the dynamic vulcanization were effective in enhancing the miscibility of PP and EPDM. The structure of the blends was controlled by the following three component phases, i.e., the phase of the dynamially valcanized EPDM, PP, and Zn-neutralized ionomer. The ternary blends showed more miscibility than the PP/EPDM binary blend. This is due to the thermoplastic interpenetrating polymer network (IPN) of the ternary blends. The structure and properties of the ternary blends differed, depending on the types and contents of ionomer, i.e., the ternary blend containing Na-neutralized ionomer did not show a thermoplastic IPN structure clearly, even though the blend was prepared by dynamic vulcanization. The ternary blend containing Zn-neutralized ionomer clearly showed the behavior of a thermoplastic IPN when the contents of ionomer and DCP were 15 parts and 1.0 part, respectively.     

无规离聚体的力学性能及其影响因素

本文对无规离聚体最基本的性能－力学性能，以及离子含量，平衡离子的性质、过量中和剂、增塑剂和制样过程对其本体力学性能的影响进行了系统的综述，反映了该领域的研究概况和较新的研究成果。     

Synthesis and properties of novel amphiphilic sulfated ionomers by the ring‐opening reaction of an epoxidized styrene–butadiene–styrene triblock copolymer

A method for the synthesis of novel sulfated ionomer of styrene–butadiene–styrene triblock copolymer (SBS) was developed. SBS was first epoxidized by performic acid in the presence of a phase‐transfer catalyst; this was followed by a ring‐opening reaction with an aqueous solution of alkali salt of bisulfate. The optimum conditions for the ring‐opening reaction of the epoxidized SBS with an aqueous solution of KHSO₄ were studied. During the ring‐opening reaction, both phase‐transfer catalyst and ring‐opening catalyst were necessary to enhance the conversion of epoxy groups to ionic groups. The products were characterized with Fourier transform infrared spectrophotometry and transmission electron microscopy (TEM). After the potassium ions of the ionomer were substituted with lead ions, the lead sulfated ionomer exhibited dark spots under TEM. Some properties of the sulfated ionomer were studied. With increasing ionic groups or ionic potential of the cations, the water absorbency and emulsifying volume of the ionomer and the intrinsic viscosity of the ionomer solution increased, whereas the oil absorbency decreased. The sulfated ionomer possessed excellent emulsifying properties compared with the sulfonated SBS ionomer. The sodium sulfated ionomers in the presence of 10% zinc stearate showed better mechanical properties than the original SBS. When the ionomer was blended with crystalline polypropylene, a synergistic effect occurred with respect to the tensile strength. The ionomer behaved as a compatibilizer for blending equal amounts of SBS and oil‐resistant chlorohydrin rubber. In the presence of 3% ionomer, the blend exhibited much better mechanical properties and solvent resistance than the blend without the ionomer. SEM photographs indicated improved compatibility between the two components of the blend in the presence of the ionomer. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of monomer‐casting polyamide 6/polymethacrylic ionomer blends

Monomer‐casting polyamide 6 (MCPA6)/polymethacrylic ionomer blends were synthesized by the in situ anionic ring‐opening polymerization of ?‐caprolactam. The polymethacrylic ionomer used in this study was a copolymer of methyl methacrylate and sodium or zinc methacrylate. Because the polymethacrylic ionomer strongly interacted with polyamide 6 (PA6) chains, it influenced the alignment of the polyamide chains. The change in the degree of the order of hydrogen bonding in MCPA6 caused by the addition of the polymethacrylic ionomer was studied with Fourier transform infrared. The change in the interaction between PA6 chains was studied with rheological measurements. The influence of the polymethacrylic ionomer on the crystallization behavior of MCPA6 was also studied with differential scanning calorimetry. The isothermal crystallization and subsequent melting behavior were investigated at the designated temperature. The commonly used Avrami equation was used to fit the primary stage of the isothermal crystallization. The Avrami exponent (n) values were evaluated to be 2 < n < 3 for the neat MCPA6 and MCPA6/polymethacrylic ionomer blends. The polymethacrylic ionomer, acting as a stumbling‐block agent in the blends, decelerated the crystallization rate with the half‐time of crystallization increasing. The polymethacrylic ionomer made the molecular chains of MCPA6 more difficult to crystallize during the isothermal crystallization process. More less perfect crystals formed in the MCPA6/polymethacrylic ionomer blends because of the interaction between the MCPA6 molecular chains and polymethacrylic ionomer. The crystallinity of the blends was depressed by the addition of the polymethacrylic ionomer. The thermal stability was also studied with thermogravimetric analysis. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Sorption and permeation behavior of water vapor and carbon dioxide gas through ethylene ionomer membranes

Sorption and permeation of water vapor and carbon dioxide gas through ethylene ionomer membranes were studied as a function of pressure. Water sorption increased with an increase of the acid content and especially degree of neutralization of ethylene ionomers. The sodium salt ionomer enhanced water sorption compared to the zinc salt ionomer. However, there was no remarkable difference of permeability coefficient of water vapor through the sodium and zinc ionomer membranes. Diffusion coefficient of the sodium salt ionomer is one order smaller than that of zinc salt ionomer, corresponding to an immobilized water structure in the sodium salt ionomer. Differential scanning calorimetry studies on water sorbed to membrane manifested that water sorbed was almost nonfreezable. Sorption of carbon dioxide gas in ethylene ionomers was a dual-mode type. The pressure dependence of permeability coefficient of carbon dioxide gas was interpreted in terms of a partial immobilization model, independent of the kind of the metal salt in ethylene ionomer.     

Effects of compositional inhomogeneity on the mechanical properties and morphology of styrene-co-methacrylate random ionomer mixtures

A series of poly(styrene-sodium methacrylate) SMANa ionomers of varying ion contents was synthesized, and mixtures of the ionomers were made to artificially broaden the compositional inhomogeneity of the SMANa ionomers at a constant ion content of 7.3 mol%. The mechanical properties of the unblended SMANa ionomer containing 7.3 mol% of ions and the ionomer mixtures were compared. It was found that the ionic moduli of the unblended ionomer and ionomer mixtures were very similar to each other, indicating that the mixing process did not change the degree of clustering. However, the slope of ionic plateau became steeper as the difference in the ion contents of two ionomers in the ionomer mixture increased, suggesting that the inhomogeneity of the matrix and cluster phases increased. It was also observed that the difference between the matrix and cluster T_gs increased as the divergence of the ion contents of two ionomers in the ionomer mixture became wider. In addition, it was found that when the difference of the two ion contents exceeded over 6 mol%, the ionomer mixture started to show a trace of phase-separation. At ca. 9 mol% of ion content difference, the ionomer mixture exhibited a third loss tangent peak, possibly due to the presence of the phase-separated matrix regions. The SAXS study showed that, even though the three-dimensional arrangement of multiplets in an ionomer matrix was not changed upon mixing two ionomers, the matrix phase became inhomogeneous.     

Synthesis and characterization of maleated ionomers via ring‐opening reaction of epoxidized styrene‐butadiene rubber with potassium hydrogen maleate and study of their behavior as compatibilizer

A novel method for synthesizing maleate ionomer of (styrene‐co‐butadiene) rubber (SBR) from epoxidized SBR was developed. The epoxidized SBR was prepared via epoxidation of SBR with performic acid formed in situ by H₂O₂ and formic acid in cyclohexane. The maleated ionomer was obtained by ring‐opening reaction of the epoxidized SBR solution with an aqueous solution of potassium hydrogen maleate. The optimum conditions were studied. It was found that it is necessary to use phase transfer catalyst and ring‐opening catalyst for enhancing the epoxy group conversion. To obtain 100% conversion addition of dipotassium maleate is important. The product was characterized by FTIR spectrophotometry and transmission electron microcroscopy (TEM). The results showed that the product was really an ionomer with domains of maleate ionic groups. Some properties of the ionomer, such as water absorbency, oil absorbency and dilute solution behavior were studied. With increasing ionic groups, the water absorbency of the ionomer increases, whereas the oil absorbency decreases. The dilute solution viscosity of the ionomer increases abruptly with increasing ionic group content. The ionomer can be used as a compatibilizer for the blends of SBS and chlorosulfonated polyethylene (CSPE). Addition of a small amount of the ionomer to the blend can enhance the mechanical properties of the blends. 3 wt % ionomer based on the blend can increase the tensile strength and ultimate elongation of the blend nearly twice. The compatibility of the blends enhanced by adding the ionomer was shown by scanning electron microscopy. The blend of equal parts of SBS and CSPE compatibilized by the ionomer behaves as an oil resistant thermoplastic elastomer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 792–798, 2006