Disruption of the multiplets in poly(styrene-co-methacrylate) ionomers by the addition of aliphatic diacid salts

Dynamic mechanical properties and morphology of poly(styrene-co-sodium methacrylate) ionomers containing disodium salts of aliphatic diacid were investigated. It was found that upon the addition of diacid salts to the ionomers, the position of the matrix loss tangent peak remained constant, but the cluster loss tangent peak shifted to lower temperatures; the size of the matrix loss tangent peak increased, but that of the cluster peak decreased. In addition, the ionomers containing diacid salts showed X-ray diffraction patterns at relatively wide angles but no DSC melting peak. Thus, it was postulated that the organic salts prohibit the ionic groups of the ionomer from forming multiplets, and that the ionic groups of the ionomer, not forming the multiplets, participate in the formation of ionic aggregates with the ionic groups of the diacid salts.     

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.     

Dynamic mechanical properties of weakly clustered poly(styrene-co-sodium citraconate) ionomers

Summary The properties of poly(styrene-co-citraconate) ionomers were investigated dynamic mechanically. It was found that the loss tangent peak for the matrix glass transition decreased with increasing content of ionic units, while the loss tangent peak for the cluster glass transition was barely detectable. However, the ionic modulus values of the citraconate ionomers as a function of the amount of ionic units were comparable to those of well-clustered methacrylate ionomers. Thus, it was postulated that the ionic modulus was affected by both clustering due to the overlapping of regions of restricted mobility and strong physical cross-links originated from the ionic association of ca. 4 ion pairs. Received: 16 March 2001/Revised version: 25 April 2001/Accepted: 27 April 2001     

Dynamic mechanical properties of polystyrene‐co‐styrenesulfonic acid copolymers neutralized with aliphatic diamines

In this article, we reported the effects of the addition of various aliphatic diamines (ADAs) on the dynamic mechanical properties of poly(styrene‐co‐styrenesulfonic acid) copolymers. It was found that the ionic modulus decreased with increasing chain length of ADAs but increased for the ADA12‐containing ionomers. Upon the neutralization of the copolymers with ADAs, a minor change in the size and position of the matrix loss tangent peak was observed. However, the position of the cluster loss tangent peaks shifted to lower temperatures, and the shift rate depended on the chain length of ADAs. Thus, it was suggested that the ADAs acted mainly as preferential plasticizer for the cluster regions. In addition, the effect of the amount of ADA on the difference between the matrix and cluster temperatures of the ionomers was strongest than that of the type of ADA or ion content. The X‐ray peak of ADA12 suggested that the ADA12 acted both as plasticizer and as filler. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

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.     

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。     

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     

离聚物单体结构对PET非等温熔融结晶过程的影响

利用差示扫描量热仪、扫描电子显微镜、偏光显微镜等方法研究了不同单体结构的乙烯甲基丙烯酸离聚物(Surlyn)、乙烯基丙烯酸离聚物(Aclyn)及苯乙烯基丙烯酸离聚物(SAA)对聚对苯二甲酸乙二酯(PET)非等温熔融结晶过程的影响.结果表明,加入离聚物后PET的结晶速率常数K由0.35提高到1.00～2.37,提高结晶速率的能力为Aclyn>Surlyn>SAA.SAA中苯环的强位阻效应使其自聚集能力下降,Surlyn中羧酸钠基团上的甲基也产生了较大的位阻,降低了其自聚集能力,Aclyn分子链中没有多余基团干扰,其自聚集能力最强.     

Viscoelastic properties of poly(styrene-co-vinylphosphonate) ionomers

Viscoelastic properties of neat and glycerol plasticized poly(styrene-co-diethyl vinylphosphonate) ionomers were investigated. Nanophase separation of a polar phase occurred due to hydrogen bonding or ionic interactions in the acid derivatives and the metal salts, respectively. Metal–phosphonate ion–dipole interactions were much stronger and more temperature persistent than the hydrogen bonding in the phosphonic acid derivatives, which were manifested by a much broader rubbery region in their viscoelastic behavior. The phosphonate interactions were thermally stable up to >250 °C, and the physically crosslinked network produced suppressed viscous flow of the ionomers to very high temperatures. Time–temperature superposition was not applicable for the SVP ionomers even at an ion content as low as 2.4 mol%. The addition of a polar plasticizer, e.g., glycerol, preferentially solvated the ionic associations and diminished the extent of the rubbery plateau of the ionomer and substantially decreased the terminal relaxation time.     

Melt flow and mechanical properties of sulfonated butyl rubber ionomers

Study of melt flow properties and mechanical properties of sulfonated butyl rubber ionomers showed that in the case of lithium ionomers addition of zinc stearate lowered obviously the melt viscosity, represented by torque value of a Brabender rheometer, and enhanced tensile strength of the ionomer up to 25% of zinc stearate, while in the case of ethylamine neutralized ionomer addition of zinc stearate lowered the melt viscosity not so obviously as in the case of lithium ionomer and slightly affected the tensile strength. Amine neutralized ionomers exhibited very low permanent sets, while the lithium ionomer showed much higher permanent set, which increased with sulfonate group and amount of zinc stearate added. Increase of neutralization degree below equivalent ratio of 1 significantly raised the melt viscosity and tensile strength. For monovalent cation ionomer, melt viscosity and tensile strength diminished with decreasing ionic potentials, but for divalent cation ionomers with increasing ionic potentials and with decreasing covalent character tensile strength decreased and melt viscosity increased. For different amine neutralized ionomers tensile strength decreased in the following orders: ethylamine > triethylamine > diethylamine; isopropylamine > ethylamine > tertiary butylamine > methylamine; ethylamine > hexylamine > dodecylamine > octadecylamine.     

Roles of mono- and di-functional organic salts as plasticizer and/or filler in styrene-based ionomers

The plasticization and/or filler effects of sodium salts of hexanoate (Na6), adipate (Na6Na), dodecanedioate (Na12Na), and dodecylbenzenesulfonate (Na12) on the dynamic mechanical properties of styrene-based ionomers were investigated. When a small amount of Na6, having one carboxylate ionic group at one end of alkyl chain, was added to a styrene-methacrylate ionomer, the salt acted as a very effective plasticizer for the ionomer cluster regions. With increasing salt contents, however, the salts became phase-separated and formed bilayer crystalline domains that acted as filler. In the case of the Na12Na and Na6Na salts, containing two carboxylate ionic groups, one at each end of alkyl chain, they formed phase-separated domains, acting as filler, in the methacrylate ionomers. Na12, possessing one sulfonate ionic group at only one end of a long alkyl chain, acted as a plasticizer in a sulfonated polystyrene ionomer. However, an excess amount of Na12 salt also formed phase-separated domains. It was also found that Na12 showed a filler effect only at much higher salt contents in comparison with Na6.     

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。     

Tangible plasticization/filler effects of sodium salts of dimer acids on the mechanical properties of styrene ionomers

The effects of the presence of dimer acid (DA) molecules in Na‐sulfonated polystyrene (PSSNa) and poly(styrene‐co Na‐methacrylate) (PSMANa) ionomers on the ionomer properties were investigated using a dynamic mechanical analysis technique. The DA decreased the matrix and cluster T_gs of PSSNa ionomer without changing the ionic modulus, suggesting that the DA resided both in the matrix and cluster regions of PSSNa ionomer and acted mainly as a plasticizer. On the other hand, the DA decreased the cluster T_g of PSMANa ionomer, without changing the matrix T_g, and also increased the ionic modulus, implying that the DA behaved like plasticizer only for the cluster regions. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

PC/PET/PE-g-MAM三元共混体系流动性的研究

以ＰＥｇＭＡＨ 和ＰＥｇＭＡＮａ 、ＰＥｇＭＡＺｎ 马来酸盐离聚物为相容剂组成ＰＣ／ＰＥＴ／ＰＥｇＭＡＭ 三元共混体系。用毛细管流变仪研究了不同ＰＥｇＭＡＭ 的接枝率及用量对共混物流动性的影响,结果表明：马来酸盐离聚物增强了ＰＣ 和ＰＥＴ 间的相容性,当其含量或接枝率较大时,可以显著降低ＰＣ／ＰＥＴ 共混物的表观粘度,提高体系的流动性,相同接枝率的ＰＥｇＭＡＮａ 对共混体系表观粘度的影响更为显著。     

Effects of the cation valence on the mechanical properties of sulfonated polystyrene ionomers containing dicarboxylate salts

The dynamic mechanical properties of Ba(II)-neutralized poly(styrene-co-styrene sulfonate) ionomers-containing Ba salt of aliphatic diacid were investigated and compared with those of Na(I)-neutralized ionomers-containing Na diacid salt. It was found that the addition of diacid salts led to a negligible change in the matrix and cluster T _gs of the Ba and Na ionomers regardless of the chain length of the aliphatic diacid salts. The log E′ of Ba ionomers, however, increased linearly with increasing chain length of Ba diacid salt, which was different from that of Na ionomers. On increasing wt% of the salts in the ionomers, the matrix T _gs of Ba and Na ionomers did not change, but the cluster T _gs increased slightly for Ba and Na ionomers, except for the Na ionomer-containing C₁₆ diacid salt. In addition, the log E′ increased linearly with the wt% of diacid salts, but the increasing rate was higher for the Ba ionomers, compared to Na ionomers. Thus, it was suggested that the Ba diacid salts would face more difficulty in the formation of multiplet with the ionic groups of the ionomers, compared to Na ionomer system; thus, more Ba diacid salts were phase-separated, which showed a stronger filler effect. In addition, since the Ba ionomers did not flow easily above the cluster T _g of the ionomers, it was proposed that the multiplets of Ba ionomers acted still as effective physical cross-links above cluster T _g, to some extent. Finally, it was concluded that the difference in anionic groups, the increasing amount of Ba salts, and the divalent cation enhanced the filler effects strongly.     

Ethylene/(meth)acrylic acid ionomers plasticized and reinforced by metal soaps

Metal soaps, also known as fatty acid salts, resemble oligomers of ethylene/methacrylic or ethylene/acrylic acid (E/(M)AA) ionomers, in that they contain carboxylic salt headgroups and long methylene sequences in their hydrocarbon tails. Such soaps might thus be expected to form miscible blends with E/(M)AA ionomers under suitable conditions, providing a separate route to increasing an ionomer's ion content and modifying its physical properties. We show here that the structure and property modifications induced by blending metal soaps into E/(M)AA ionomers are complex, and depend on both the neutralizing cation and on whether the hydrocarbon tails are crystallizable. In the melt at sufficiently high temperatures, all blends show a coassembled structure, where the salt groups of the soap coaggregate with the salt groups on the ionomer; despite the high ion content of these blends, they retain the melt processability characteristic of neat E/(M)AA ionomers of much lower ion content. Non-crystallizable magnesium oleate and magnesium erucate act as permanent plasticizers, lowering the matrix glass transition temperature. Magnesium stearate, whose alkyl tails easily form a rotator phase, can slowly ‘cocrystallize’ with ethylene sequences in the ionomers, leading to high moduli; however, primary crystallization is suppressed in these blends. Finally, while sodium stearate is miscible with the ionomers at elevated temperatures, it phase-separates on cooling, prior to crystallization of the ionomer; such blends are essentially composites of pure stearate and ionomer phases, with their associated individual properties, rather than possessing new structures or properties resulting from coassembly.     

Wetting properties of polystyrene ionomers treated with plasma source ion implantation

The wetting properties of polystyrene‐based ionomers treated with plasma source ion implantation (PSII) were investigated by the measurement of water contact angles. When sulfonated ionomers were aged for a few days, the hydrophobic recovery for the ionomers became much slower than that for the nonionic polymers. However, when the samples were aged over 20 days, the water contact angle of the ionomers converged with that of the nonionic polymer. Thus, it was concluded that the ionic interaction between the ionic groups and the presence of ionic groups together resulted in the slow hydrophobic recovery and that the aging effect was significant for the ionomers. For the methacrylate ionomer of low ion content, on the other hand, it was found that the PSII treatment produced only a small change in hydrophobic recovery behavior. Thus, it was suggested that the low ionic content coupled with the small size of the ionic unit might cause changes only of a very insignificant degree in hydrophobic recovery behavior. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2500–2504, 2002     

Preparation and thermal properties of liquid crystalline ionomers having mesogenic ester side chains containing three phenyl groups

A series of liquid crystalline (LC) copolymers having both the repeat units of mesogenic ester side chains containing three phenyl groups and the repeat units possessing an acid group were prepared. The acid groups of the LC copolymers were neutralized with sodium acetate to give a varying degree of neutralization. It was found that the LC properties of the ionomers depended strongly on both the relative amount of the units having the mesogenic side chains and the amount of ionic units. It was also observed that the formation of the nematic phase of the LC ionomers was suppressed by the increase in ion contents. After the analysis of the thermal data of the phase transitions, it was suggested that the transition temperatures of the LC phases of the copolymers and their ionomer forms, and the temperature ranges for the LC phases were affected by the relative amounts of both mesogenic and acidic units and by the degree of neutralization, simultaneously.     

Effects of contact surface area of chains on the mechanical properties of poly(methyl methacrylate-co-acrylate) ionomers

Summary The dynamic mechanical properties of a new ionomer system, poly(methyl methacrylate-co-sodium acrylate), were studied. In addition, to investigate the effect of the chemical structure of ionic group on the mechanical properties, the data obtained from the sodium acrylate ionomers were compared to those obtained from sodium methacrylate ionomers. The matrix and cluster T _gs for the methacrylates were found to be higher than those for the acrylates. It was argued that the difference in the T _gs might be explained with the concept of contact surface area of the chain. Received: 27 November 1998/Revised version: 6 January 1999/Accepted: 13 January 1999