CPVC-cg-AA钠盐离聚体的合成、表征和力学性能

用自制的氯化聚氯乙烯接枝丙烯酸(CPVC-cg-AA)与NaOH中和制备出Na盐离聚体。用红外光谱、核磁共振等方法对离聚体进行了表征和测试。结果表明:通过CPVC-cg-AA与NaOH中和成功制备了Na盐离聚体;离聚体的力学性能随着体系中和度的增加而提高;在中和度为100%时,随着Na离子含量的增加,离聚体的拉伸强度先上升后下降,而断裂伸长率变化不大。     

聚乙烯氯化原位接枝马来酸酐离聚体的制备、表征及性能

采用氯化原位接枝技术合成了氯化聚乙烯接枝马来酸酐(CPE-cg-MAH),之后将接枝物与碱金属的氢氧化物反应制备氯化聚乙烯离聚体,并用离聚体制备了氯化聚乙烯橡胶(CM)。综合性能测试结果表明,离聚体型CM的拉伸强度比传统CM要高15%~20%左右;扯断伸长率、压缩永久变形、低温性能都能达到行业所需的基本要求;红外光谱显示,离聚体在1 584 cm-1和1 406 cm-1处出现了新的吸收峰;扫描电镜和透射电镜图中可以看到明显的离子聚集体的存在。     

乙烯-丙烯酸钙离聚体的制备及研究

用动态中和法合成了乙烯-丙烯酸共聚物(EAA)的钙离聚体,研究了不同含量的钙离子在哈克密炼机中熔融共混的中和效果,并用双螺杆挤出机挤出造粒制备了离聚体薄膜,用红外光谱(FT-IR)和DSC等手段进行了表征和分析,并通过红外理论分析得到离聚体近似的中和度.     

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。     

熔融法制备聚乙烯离聚体及其性能研究

在熔融状态下,采用马来酸酐接枝的线性低密度聚乙烯(LLDPE-g-MAH)与SnCl4制备聚乙烯离聚体,研究了聚乙烯离聚体的性能及其对线性低密度聚乙烯( LLDPE)性能影响.研究表明,聚乙烯离聚体的力学性能明显优于LLDPE-g-MAH的,熔点与结晶度降低,同时离聚体结晶温度向高温方向移动；LLDPE/LLDPE-g-MAH/SnCl4体系,随着体系中LLDPE-g-MAH含量增多,体系中生成的离聚体增多,力学性能略微提高,体系的黏弹行为由黏性转为弹性.     

含规整PMMA支链的共聚物及其离聚体的力学性能

研究了用聚甲基丙烯酸甲酯（ＰＭＭＡ）大单体与丙烯酸丁酯（ＢＡ）共聚制得的接枝共聚物及其与ＢＡ及丙烯酸（ＡＡ）共聚并中和制得的离聚体的力学性能与支链分子量、支链含量、共聚物分子量、羧基含量、中和度及离子种类的关系．结果表明这二种产物均呈现较好的热塑性弹性体行为，而离聚体的性能更为优越。     

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。     

含聚氧乙烯支链的三元共聚物及其离聚体

用聚氧乙烯（PEO）大单体与丙烯酸丁酯（BA）及丙烯酸（AA）共聚，合成了三元规整接枝共聚物，并经离子中和生成了离聚体。研究了共聚条件对各单体转化率及共聚物相对分子质量的影响。产物经纯化后用红外光谱仪，膜渗透压计，凝胶渗透色谱仪等进行了表征。研究了共聚物的平均接枝数，结晶度，力学性能及吸水性，还研究了丙烯酸质量分数，PEO质量分数，中和度及不同离子对离聚体力学性能的影响。结果表明，共聚开始大单体的转化速率大于小单体的，后期则相反。大单体转化率随引发剂用量增加而增加，随大单体占总单体的质量分数及大单体相对分子质量增加而下降，共聚物相对分子质量则随聚合时间增加而增加，随引发剂用量增加而降低。共聚物有一定结晶度及100％－200％的吸水率。三元共聚物中和成离聚体后拉伸强度明显增加，呈热塑性弹性体性质。铅或锌离子中和的离聚体拉伸强度最大。     

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%。     

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。     

Dynamic mechanical properties of three different combinations taken from styrene-co-itaconate, styrene-co-methacrylate, and styrene-co-sulfonate ionomers

Dynamic mechanical properties of three different styrene-based ionomer blends containing ca. 5 mol% of ionic repeat units were investigated; the three ionic units were itaconate (ITANa), methacrylate (MANa), and styrenesulfonate (SNa). For SNa-MANa ionomers, it was observed that this ionomer system showed only two loss tangent peaks, implying that this ionomer system resembles a typical miscible system. When the ion content increased, however, the ionomer blend showed two cluster loss tangent peaks, indicating the presence of phase-separated cluster regions. This suggests that, with increasing ion content, the role of ionic units becomes more important than that of host non-ionic units to determine ionomer properties. In the case of ITANa-MANa and ITANa-SNa ionomers, however, it was suggested that the multiplets of the MANa and SNa ionomers might be disrupted upon the addition of the ITANa ionomers. In addition, the SEM images showed that the fracture surfaces of ionomers changed upon blending.     

Melt synthesis of sulfonated EPDM ionomers in batch and continuous processes

Zinc-neutralized sulfonated EPDM ionomers (Zn-SEPDM) were prepared by batch and continuous melt sulfonation processes, and the ionomer products were compared with ionomers synthesized by sulfonation of EPDM in homogeneous solution. The efficiency of a batch melt sulfonation using an intensive mixer as a reactor was comparable to that of the solution sulfonation process, but the efficiency of the melt sulfonation in a twin-screw extruder was considerably lower, which was thought to be a consequence of a relatively short reaction residence time due to limitations of the equipment. Melt neutralization was not complete, which produced a dark colored product. However, the incomplete neutralization and the color of the product did not affect the mechanical properties of the melt sulfonated ionomers, which were comparable to those of ionomers made by conventional solution sulfonation. The metal sulfonate concentration alone determined the mechanical properties of the ionomer. Melt sulfonation of Zn-SEPDM ionomers by batch or continuous melt processes appears to be a practical alternative to solution sulfonation, but further optimization of the melt sulfonation processes is needed to ensure uniform sulfonation and complete neutralization.     

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.     

Plasticization effects on the mechanical properties and morphology of cobalt and sodium neutralized poly(ethyl acrylate-co-acrylate) ionomers

The present study aimed to investigate the effects of plasticization on the mechanical properties and morphology of poly(ethyl acrylate) ionomers neutralized with either Co²⁺ or Na⁺. In experiments, the dynamic mechanical properties of divalent Co²⁺-neutralized poly(ethyl acrylate) ionomers containing polar and non-polar plasticizers were compared with those of the monovalent Na⁺-neutralized ionomers. In the case of the ionomers plasticized with non-polar 4-decylaniline (4-DA), residing in non-ionic regions, the matrix and cluster T_gs of the ionomer decreased with increasing 4-DA contents. The decreasing rates of the matrix and cluster T_gs were found to be similar at 0.8 and 1.0 °C/(wt% of 4-DA) for the Co²⁺ and Na⁺ ionomers, respectively. The ionic modulus of the Co²⁺ ionomer changed only slightly with increasing 4-DA contents, but that of the Na⁺ ionomer decreased noticeably. In the SAXS study, it was observed that the un-plasticized Co²⁺ ionomer showed a strong small angle upturn and a very broad SAXS peak, indicating that the ionomer phase was compositionally heterogeneous. The plasticization of the Co²⁺ ionomer with 4-DA, however, induced a well-developed SAXS peak that was comparable to that of the un-plasticized Na⁺ ionomer. These results suggested that the addition of 4-DA to the Co²⁺ ionomer made the ionomer have more multiplets at a prevalent distance, leading to more clustering. In the case of the Co²⁺ ionomers plasticized with polar glycerol (Gly) that acted mainly as multiplet plasticizer, a very weak cluster glass transition, decreasing ionic modulus and only a well-developed small angle upturn were observed. These indicated that the addition of Gly to the Co²⁺ ionomer disrupted the multiplet formation, resulting in lower clustering.     

氢化羧基丁苯橡胶离聚体的表征及其与聚乙烯共混

从氢化羧基丁苯胶乳出发，与钠、钾、锂、镁、锌和铅等金属离子中和，生成羧基丁苯离聚体胶乳。用IR，DSC，TEM对试样进行了表征，同时测定了不同离子中和及不同氢化度的离聚体物理机械性能，还将钾离聚体与聚乙烯以不同比例共混。结果表明，该离聚体既含有离子微区，又含有结晶微区；各种离聚体均呈现热塑性弹性体性能，其中铅及锂的离聚体拉伸强度最大；钾离聚体与聚乙烯以质量比为25／75-50／50共混时，试样拉伸强度呈现协同效应。     

Properties of polyamic acid ionomers

Polymers containing amic acid units were produced by reacting an oligomer based on polytetramethylene oxide (PTMO) with 1,2,4,5-benzenetetracarboxylic dianhydride (BTDA). Neutralization by a metal salt produced amic acid ionomers. Similar to other ionomer systems, neutralization from the acid to the ionomer led to the formation of a separate ionic phase as determined by dynamic mechanical analysis. Phase separation resulted in a substantial increase in mechanical properties. The effect of neutralization level, cation, soft-segment molecular weight, and soft-segment end group on mechanical and thermal properties was investigated. © 1993 John Wiley & Sons, Inc.     

Preparation,characterization, and some properties of ionomers from a sulfonated styrene–butadiene–styrene triblock copolymer without gelation

The conditions for the sulfonation of a highly unsaturated styrene–butadiene–styrene triblock copolymer (SBS) in cyclohexane containing a small amount of acetone with acetyl sulfate made by sulfuric acid and acetic anhydride without gelation were studied. After neutralization with metallic ions, the ionomers were characterized with IR spectrophotometry, dynamic mechanical analysis, and transmission electron microscopy. The melt flow, solution properties, and mechanical properties of the ionomers were studied. The results showed that gelation occurred during the sulfonation of SBS in cyclohexane at a 5–10% concentration without acetone, whereas in the presence of 5–10 vol % acetone, sulfonation proceeded smoothly without gelation. Transmission electron microphotographs of the lead ionomer indicated the presence of ionic domains. A dynamic mechanical spectrum showed the presence of three transition temperatures: ?82.9, 68, and 96.5°C. The melt viscosity of the ionomer increased with the sulfonate content. The melt viscosity of the different ionomers neutralized with different cations seemed to decrease with decreasing ionic potential for both monovalent cations and divalent cations The solution viscosity of the sodium‐sulfonated ionomer increased with increasing sulfonate content. The ionomer still behaved as a thermoplastic elastomer and showed better mechanical properties than the original SBS. The tensile strength of the different ionomers decreased as follows. For the monovalent cations, it decreased with decreasing ionic potentials: Li⁺ > Na⁺ > K⁺. For the divalent cations, it decreased with increasing ionic potentials: Pb²⁺ > Zn²⁺ > Mg²⁺. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1398–1404, 2005