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     

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.     

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.     

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。     

从聚苯乙烯大单体—丙烯酸丁酯—丙烯酸三元共聚物中和制得的热塑性弹性体的力学性能

研究了经离子中和的聚苯乙烯大单体与丙烯酸及丙烯酸丁酯共聚物的力学性能,包括中和方法、羧酸含量、中和度、金属离子种类及聚苯乙烯支链的含量及分子量等对力学性能的影响。这种双重物理交联产物的强度为未中和的三元共聚物或经离子中和的丙烯酸—丙烯酸丁醋共聚物的二倍。动态力学谱表明有二个玻璃化温度,呈现微观相分离。     

Synthesis and properties of random poly(lactic acid)-based ionomers

A random poly(lactic acid), PLA, based ionomer was synthesized by copolymerizing a methacrylate-terminated PLA macromonomer and methyl methacrylate. The copolymerization kinetics were studied using ¹H NMR spectroscopy and the copolymer composition was characterized by ¹³C NMR spectroscopy. Carboxylic acid groups were introduced into the copolymer by reacting the hydroxyl end groups of the PLA macromonomer with succinic anhydride, and the acid groups were neutralized with metal acetates to produce Na-, Ca-, and Y-PLA ionomers. Significant increases in T_g were observed for the ionomers and thermomechanical analysis indicated that the ionomers were more resistant to penetration by a weighted probe and an apparent rubbery plateau was observed above T_g. The ionomers were more hydrophilic than PLA, but relatively low water absorption could be achieved for the Ca²⁺-salt ionomer.     

Effects of acid neutralization on the morphology and properties of organoclay nanocomposites formed from K+ and Na+ poly(ethylene-co-methacrylic acid) ionomers

Nanocomposites were prepared by melt blending various sodium (Na⁺) and potassium (K⁺) ionomers formed from poly(ethylene-co-methacrylic acid) and the M₂(HT)₂ organoclay formed from montmorillonite (MMT). The effects of the neutralization level of the acid groups and the precursor melt index on the morphology and properties of the nanocomposites were evaluated using stress-strain analysis, wide angle X-ray scattering (WAXS), and transmission electron microscopy (TEM) coupled with particle analysis. The aspect ratio generally increases as the neutralization level increases, except for Na⁺ ionomer nanocomposites with neutralization levels >50%. It appears from both WAXS and TEM analyses that Na⁺ ionomer nanocomposites have higher levels of MMT exfoliation and particle orientation in the flow direction than K⁺ ionomer nanocomposites. DSC results indicate that the level of crystallinity in the Na⁺ ionomers generally increases slightly with MMT addition, while the crystallinity in the K⁺ ionomers decreases slightly with MMT addition. The relative modulus of K⁺ ionomer nanocomposites increases as the degree of neutralization increases. The relative moduli of Na⁺ ionomer nanocomposites are higher than the relative modulus of K⁺ ionomer nanocomposites, likely due to the increased crystallinity of the Na⁺ ionomers and the decreased crystallinity of the K⁺ ionomers upon addition of MMT, the higher exfoliation levels measured by the aspect ratios and the particle densities, and the higher particle orientation indicated by TEM and WAXS. The relative modulus generally increases as the aspect ratio increases. The elongation at break generally decreases as the MMT content increases and as the neutralization level increases for both ionomer types. The fracture energy of most of the ionomers increases with the addition of MMT, reaches a maximum between 2.5 and 5 wt% MMT, and then decreases upon further MMT addition.     

Hydrophobic recovery behavior of PMMA and PEA ionomers treated with PSII

The surfaces of poly(methyl methacrylate) (PMMA)‐based and poly(ethyl acrylate) (PEA)‐based ionomers were treated either with plasma or with plasma source ion implantation (PSII), and their hydrophobic recovery behavior was studied by measuring water contact angles. It was found that the hydrophobic recovery of the plasma‐treated and PSII‐treated surfaces of PMMA ionomers was much slower than that of the acid‐form copolymers. This was due to the presence of hydrophilic ionic groups on the ionomer surface. In addition, in the case of the PMMA ionomers, a slow hydrophobic recovery behavior for a long period of time was observed. In the case of the PEA ionomer, the water contact angle values were found to be larger than those for the PMMA ionomers. When the contact angle values of the PMMA and PEA ionomers were compared to those of polystyrene (PS) ionomers, it was found that the order of ionomers showing higher angle value at comparable aging time was as follows: PS ionomer > PEA ionomer > PMMA ionomer. This was due to the difference in polarity and matrix glass transition temperature of the ionomers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3100–3106, 2003     

Effect of metallic ions in photo-induced graft copolymerization onto cellulose

In photo-induced graft copolymerization of methyl methacrylate onto cellulose, the effect of metallic ions as sensitizer was investigated. Some metallic ions were effective in their adsorbed states and accelerated the formation of grafts in the order Fe²⁺ > Ag⁺ > Fe³⁺. However, Cu²⁺ acted negatively, and little effect was observed for Co²⁺, Ni²⁺, Mn²⁺, Zn²⁺, and Cr³⁺. In the systems in which aqueous metallic salt solutions were added, the formation of grafts was generally depressed, but Fe³⁺ was an exception. The effect of metallic ions on the scission reaction of cellulose main chains did not necessarily agree with the effect on the formation of grafts. This is attributed to the varied interaction between cellulose and the different active species produced by irradiation, depending on the type of metallic ions used.     

Facile Bulk Synthesis of Homogeneous and Transparent Nanocrystals Hybrids via In Situ Transformation of Ionomers into CdS Quantum-Dot-Polymer

We systemically report on a method for fabricating bulk CdS QD-polymer hybrids nanocomposites with tunable control photoluminescence (PL) by using as-prepared ionomers. Firstly, we rationally designed to synthesize well-dispersed PMMA/Cd(AA)₂ (cadmium acrylate) ionomers containing different concentrations of Cd²⁺ ion clusters via free-radical polymerization. And then, we introduced H₂S gas into the ionomer solutions to obtain transparent PMMA/CdS QD-polymers in situ. Subsequently, we employed PMMA/CdS QD-polymers to further produce claviform CdS/PMMA hybrid nanocomposites via in situ bulk polymerization. The properties of as-prepared QD-polymers and their hybrid nanocomposites were thoroughly investigated by Ultraviolet–visible (UV-vis), transmission electron microscope (TEM), Fourier transform infrared spectra (FT-IR), photoluminescence (PL), thermogravimetric analyses (TGA) measurements. We have found that these QD-polymers exhibit uniform dispersity, good optical property and an obvious advantage on thermal stability, along with facilely producing bulk nanocrystal/polymer hybrid nanocomposites with a large scale.     

Rheological properties,tensile properties,and morphology of PP/EPDM/lonomer ternary blends

The rheological and tensile properties and the morphology of polypropylene (PP)/ethylenepropylene-diene terpolymer(EPDM)/ionomer ternary blends were investigated, using a rheometric dynamic spectrometer (RDS), a dynamic mechanical thermal analyzer (DMTA), a tensile tester, and a scanning electron microscope (SEM). Two kinds of poly(ethylene-co-methacrylic acid) (EMA) ionomers, neutralized with different metal ions (Na⁺ and Zn⁺⁺), were used. Blends were melt-mixed, using a laboratory internal mixer at 190°C. The composition of PP and EPDM was fixed at 50/50 by wt % and the EMA ionomer contents were varied from 5 to 20 wt %, based on the total amount of PP and EPDM. It was found that the ternary blends, containing Na-neutralized ionomer, showed considerably different rheological properties and morphology as compared to the PP/EPDM binary blends, due to the compatibilizing effect of the ionomer for PP and EPDM, while the ternary blends, containing the Zn-neutralized ionomer, did not. The compatibilizing effect was most prominent at 5 wt % ionomer concentration. © 1994 John Wiley & Sons, Inc.     

Bulk and emulsion copolymerizations of n-butyl acrylate and poly(methyl methacrylate) macromonomer

Bulk and emulsion copolymerizations of an ω-unsaturated poly(methyl methacrylate) (PMMA) macromonomer with n-butyl acrylate (n-BA) were investigated. The reactivity of PMMA macromonomer in bulk copolymerization with n-BA was found to be lower than that of methyl methacrylate monomer with n-BA. The incorporation of PMMA macromonomer into poly(butyl acrylate) (PBA) latex particles by miniemulsion copolymerization was proved by high performance liquid chromatography-silica adsorption spectroscopy. Dynamic mechanical studies showed that PMMA macromonomer was grafted to the PBA backbone, and the degree of grafting increased as the ratio of PMMA macromonomer to n-BA increased. Microphase separation of the PMMA macromonomer grafts was observed at higher ratio of macromonomer (higher or equal to 10% weight of macromonomer based on total polymer phase). The n-BA/PMMA macromonomer copolymer behaved completely differently from the physical blend of PBA and PMMA macromonomer particles of the same composition. © 1996 John Wiley & Sons, Inc.     

Degree of crosslinking and physical properties of dimethyloldihydroxyethyleneurea/acrylic acid crosslinked cotton fabrics after treatment with various metallic salts

Three metallic salts were used to posttreat dimethyloldihydroxyethyleneurea (DMDHEU)/acrylic acid (AA) crosslinked cotton fabrics, and the results showed that at a given value of the tensile strength retention (TSR), the dry crease recovery angle (DCRA) and wet crease recovery angle (WCRA) of the crosslinked and posttreated fabrics were higher than those of the DMDHEU–AA‐treated fabrics, and those of the crosslinked and posttreated fabrics were in the order of Ag⁺ > Cu⁺² > Al⁺³. The DCRA and TSR values for the crosslinked and posttreated fabrics were higher than those for the DMDHEU–AA‐crosslinked fabrics, and those for the crosslinked and posttreated fabrics were in the order of Ag⁺ > Cu⁺² > Al⁺³; however, WCRA values for the crosslinked and posttreated fabrics were lower than those for the DMDHEU–AA‐crosslinked fabrics, and those for the crosslinked and posttreated fabrics were ranked as Ag⁺ > Cu⁺² > Al⁺³ at a given number of crosslinks per anhydroglucose unit. IR spectra clearly revealed the different interactions and bonding states between the hydroxyl group of the cellulose and the various metallic ions and the strength of the interaction. All crosslinked and posttreated fabric samples showed good odor absorption and antibacterial and washing‐fastness properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 584–594, 2005     

Effects of acid neutralization on the properties of K+ and Na+poly(ethylene-co-methacrylic acid) ionomers

The effects of the degree of neutralization of the acid groups and, to some extent, the precursor melt index on the thermal, rheological, and mechanical properties of two series of poly(ethylene-co-methacrylic acid) (EMAA) ionomers, one based on sodium (Na⁺) cations and one based on potassium cations (K⁺), were examined. Differential scanning calorimetry (DSC) and modulus results indicate that the secondary crystallization of the ionomers is generally completed 21 days after melt processing. DSC results indicate that the extent of crystallization increases with increasing neutralization level. The mechanical relaxation seen by dynamic mechanical analysis (DMA) in the vicinity of the secondary crystal melting point shifts to higher temperatures as the neutralization level increases. The rheological properties increase with decreasing precursor melt index and with increasing neutralization level to a lesser extent. The ionomer modulus and yield strength increase with increasing neutralization level up to 40% neutralization and then plateau or slightly decrease with further neutralization. The plateaus/maxima may be the result of an optimal spacing of alkaline ions and carboxyl groups within ionic groups at neutralization levels near 33%. The elongation at break and the Izod impact strength decrease with increasing neutralization. The modulus, yield stress, and impact strength are generally lowest for the ionomers with the highest precursor melt index.     

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。     

Fracture mechanics investigation on the PP/EPDM/ionomer ternary blends using j-integral by locus method

The fracture mechanics investigation of the polypropylene (PP)/ethylene–propylene–diene terpolymer (EPDM)/ionomer ternary blends was performed in terms of the J-integral by measuring fracture energy via the locus method. Blends were prepared in a laboratory internal mixer. The composition of PP and EPDM was fixed at a 50/50 ratio by weight. Two kinds of Poly(ethylene-co-methacrylic acid) (EMA) ionomers were used. The J-integral value at crack initiation, Jc, of the PP/EPDM/EMA ionomer ternary blends were affected by the cation types (Na⁺ or Zn²⁺) and contents (5–20 wt %) of the added EMA ionomers. The ternary blend having 5 wt % of Na-neutralized ionomer showed a higher Jc value than that of any other ternary blends. The results were discussed with regard to the fracture topology by a scanning electron microscope (SEM). © 1994 John Wiley & Sons, Inc.     

Polyurethane anionomers using phenolphthalins. II

Polyurethane anionomers based on phenolphthalins have been characterized by differential scanning calorimetry, swelling, and mechanical studies. DSC study shows that introduction of ionic groups into the polymer chain lowers the T_g of the polyurethane. Swelling studies reveal that water uptake is high for ionomers. From the tensile data we observe that Zn⁺² neutralized ionomers showed enhanced properties. ©1996 John Wiley & Sons, Inc.     

Evaluation of polymethacrylic ionomer as compatibilizers for MCPA6/clay composites

The compatibilization effects provided by polymethacrylic ionomer (PMMA ionomer) on monomer‐casting polyamide6 (MCPA6)/clay (pristine sodium montmorillonite) composites were studied in this work. The PMMA ionomer used in this study was sodium polymethacrylate ionomer (PMMA Na⁺‐ionomer), which is a copolymer of methyl methacrylate and sodium methacrylate, prepared using emulsion polymerization. MCPA6/clay/PMMA Na⁺‐ionomer composites were prepared by in situ anionic ring‐opening polymerization (AROP) of ε‐caprolactam (CLA). X‐ray diffraction (XRD) and transmission electron microscopy (TEM) plus rheological measurement were used to characterize those composites. The results indicated that PMMA Na⁺‐ionomer is a good compatibilizer for this system. With increasing PMMA Na⁺‐ionomer content, a better dispersion of clay layers was successfully achieved in the MCPA6 matrix. Furthermore, differential scanning calorimetry (DSC) and XRD results indicated that well dispersed silicate layers limit the mobility of the MCPA6 molecule chains to crystallize, reduce the degree crystalline, and favor the formation of the γ‐crystalline form of the MCPA6 matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008