Characterization of the interaction energies for polystyrene blends with various methacrylate polymers

The binary interaction energies between styrene and various methacrylates were determined from newly examined phase boundaries with lattice–fluid theory. Because the blends of polystyrene (PS) and poly(cyclohexylmethacrylate) (PCHMA) were only miscible at high molecular weights when the blends were prepared by solution casting from tetrahydrofuran, we examined the miscibility of other blends by changing the molecular weights of PS or methacrylate polymers. On the basis of the phase‐separation temperature caused by the lower critical solution temperature, the miscibility of PS with the various methacrylates appeared to be in the order PCHMA > poly(n‐propyl‐methacrylate) (PnPMA) > poly(ethyl methacrylate) (PEMA) > poly(n‐butyl‐methacrylate) (PnBMA) > poly(iso‐butyl‐methacrylate) > poly(methyl methacrylate) (PMMA) > poly(tert‐butyl methacrylate), and the branching of butylmethacrylate appeared to decrease the miscibility with PS. The interaction energies between PS with various methacrylates obtained from phase boundaries with lattice–fluid theory reached minimum value corresponding to the styrene/n‐propylmethacrylate interaction. They were in the order PnPMA < PEMA < PCHMA < PnBMA < PMMA. The difference in the order of miscibility and interaction energies might be attributed to the terms related to the compressibility. The phase‐separation temperatures calculated with the interaction energies obtained here indicated that the PS/PEMA and PS/PnPMA blends at high molecular weights were miscible, whereas the PS/PnBMA blends were immiscible at high molecular weights. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 2666–2677, 2000     

Blends of poly(2,6–dimethyl–1,4–phenylene oxide) with styrene copolymers

Binary blends of poly(2,6–dimethyl–1,4–phenylene oxide) (PPE) with various styrene copolymers were investigated. Poly(styrene–co–acrylonitrile) (SAN), poly[styrene–co–(methyl methacrylate)] (SMMA), poly[styrene–co–(acrylic acid)] (SAA) and poly[styrene–co–(maleic anhydride)] (SMA) are only miscible with PPE when the amount of comonomer is rather small. From calculated binary interaction densities it can be concluded that the strong repulsion between PPE and comonomer limits miscibility. In blends of PPE with SAN, as well as with ABS, the inter-facial tension between the blend components is significantly reduced upon addition of polystyrene–block–poly–(methyl methacrylate) diblock copolymers (PS–b–PMMA) and polystyrene–block–poly (ethylene–co–butylene)–block–poly–(methyl methacrylate) triblock copolymers (PS–b–PEB–b–PMMA). They show a profound influence on morphology, phase adhesion and mechanical blend properties.     

Phase behavior of tetramethylpolycarbonate blends with styrene‐based methacrylate copolymers and their interaction energies

The miscibility of tetramethylpolycarbonate (TMPC) blends with styrenic copolymers containing various methacrylates was examined, and the interaction energies between TMPC and methacrylate were evaluated from the phase‐separation temperatures of TMPC/copolymer blends with lattice‐fluid theory combined with a binary interaction model. TMPC formed miscible blends with styrenic copolymers containing less than a certain amount of methacrylate, and these miscible blends always exhibited lower critical solution temperature (LCST)‐type phase behavior. The phase‐separation temperatures of TMPC blends with copolymers such as poly(styrene‐co‐methyl methacrylate), poly(styrene‐co‐ethyl methacrylate), poly(styrene‐co‐n‐propyl methacrylate), and poly(styrene‐co‐phenyl methacrylate) increase with methacrylate content, go through a maximum, and decrease, whereas those of TMPC blends with poly(styrene‐co‐n‐butyl methacrylate) and poly(styrene‐co‐cyclohexyl methacrylate) always decrease. The calculated interaction energy for a copolymer–TMPC pair is negative and increases with the methacrylate content in the copolymer. This would seem to contradict the prediction of the binary interaction model, that systems with more favorable energetic interactions have higher LCSTs. A detailed inspection of lattice‐fluid theory was performed to explain such phase behavior. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1288–1297, 2002     

Miscibility of Halogen-containing Polymethacrylates with Various Poly(alkyl acrylate)s

The miscibility behavior of a series of halogen-containing polymethacrylates with poly(methyl acrylate), poly(ethyl acrylate), poly(n-propyl acrylate) and poly(n-butyl acrylate) was investigated by differential scanning calorimetry and for lower critical solution temperature (LCST) behavior. Poly(chloromethyl methacrylate), poly(1-chloroethyl methacrylate), poly(2-chloroethyl methacrylate), poly(2,2-dichloroethyl methacrylate), poly(2,2,2-trichloroethyl methacrylate), poly(2-fluoroethyl methacrylate) and poly(1,3-difluoroisopropyl methacrylate) are miscible with some of the poly(alkyl acrylate)s. Most of the miscible blends show LCST behavior. However, poly(3-choloropropyl methacrylate), poly(3-fluoropropyl methacrylate), poly(4-fluorobutyl methacrylate), poly(1,1,1,3,3,3-hexafluoroisopropyl methacrylate), poly(2-bromoethyl methacrylate) and poly(2-iodoethyl methacrylate) are immiscible with any of the poly(alkyl acrylate)s studied. © 1997 John Wiley & Sons, Ltd.     

Understanding the Miscibility and Morphology of Poly(methyl methacrylate) and Styrenic Copolymer Blends of Tunable Domain Sizes

In the present study, we have investigated the miscibility, morphology and mechanical behavior of poly(methyl methacrylate) (PMMA) blends with a series of poly(styrene-co-maleic anhydride) (SMA) copolymers containing varying amounts of maleic anhydride (MA) content (from 8 to 26%). The experimental findings have been substantiated by the modeling studies to gain fundamental understanding of the observed phenomena with respect to the miscibility of the PMMA and SMA blends of a given MA content. The morphological differences, molecular weights, domain sizes and mechanical behavior of the blends at a given ratio of PMMA and copolymers have been investigated and a correlation has been made between the morphological understanding to the molecular weights and mechanical properties. The results indicate that the PMMA/SMA blends are miscible only at a certain MA content providing transparent PMMA/SMA blends without affecting any of the enabling properties of PMMA that are of commercial interest through a facile melt mixing process. The surface hardness and % recovery (nano-indentation) of these blends were evaluated as well to gain fundamental understanding of the surface characteristics and mechanicals of the blends.     

Miscible blends of amorphous polymers

Thirty-five polymethacrylate/chlorinated polymer blends were investigated by differential scanning calorimetry. Poly(ethyl), poly(n-propyl), poly(n-butyl), and poly(n-amyl methacrylate)s were found to be miscible with poly(vinyl chloride) (PVC), chlorinated PVC, and Saran, but immiscible with a chlorinated polyethylene containing 48% chlorine. Poly(methyl) (PMMA), poly(n-hexyl) (PHMA), and poly(n-lauryl methacrylate)s were found to be immiscible with the same chlorinated polymers, except the PMMA/PVC, PMMA/Saran, and PHMA/Saran blends, which were miscible. A high chlorine content of the chlorinated polymer and an optimum CH₂/COO ratio of the polymethacrylate are required to obtain miscibility. However, poly(methyl), poly(ethyl), poly(n-butyl), and poly(n-octadecyl acrylate)s were found to be immiscible with the same chlorinated polymers, except with Saran, indicating a much greater miscibility of the polymethacrylates with the chlorinated polymers as compared with the polyacrylates.     

Miscibility of polycarbonates with copolymers containing cyclohexylmethacrylate

We prepared various copolymers containing styrene and methacrylates to examine their miscibility with polycarbonates such as bisphenol A polycarbonate (PC), dimethylpolycarbonate (DMPC), and tetramethylpolycarbonate (TMPC). Among the various copolymers examined, poly(methyl methacrylate‐co‐cyclohexylmethacrylate) [P(MMA–CHMA)] copolymers containing proper amounts of cyclohexylmethacrylate (CHMA) formed miscible blends with PC and DMPC, whereas TMPC did not form a miscible blend with P(MMA–CHMA). However, TMPC was miscible with poly(styrene‐co‐cyclohexylmethacrylate) [P(S–CHMA)] copolymers containing less than about 40 wt % CHMA, whereas PC and DMPC were always immiscible with P(S–CHMA). Miscible blends exhibited lower critical solution temperature (LCST)‐type phase behavior. Binary interaction energies were calculated from the observed phase boundaries with lattice–fluid theory combined with a binary interaction model. The quantitative interaction energy of each binary pair indicated that the phenyl ring substitution of polycarbonate with methyl groups did not lead to interactions that were favorable for miscibility with methyl methacrylate (MMA) and CHMA, but it did lead to favorable interactions with styrene. The addition of CHMA to MMA initially increased the LCST but ultimately led to immiscibility with PC and DMPC; however, addition of CHMA to styrene always decreased the LCST with TMPC. The increased LCST of PC or DMPC blends stemmed from intramolecular repulsion between MMA and CHMA, whereas the decreased LCST of TMPC/P(S–CHMA) blends with CHMA content came from negative interaction energy between styrene and CHMA. © 2001 John Wiley & Sons, Inc. J Polym Sci Part B: Polym Phys 39: 1948–1955, 2001     

Novel Silanol-Containing Polymers and Their Blends

ABSTRACT

Novel 4-vinylphenyldimethylsilanol polymer (PVPDMS) and co-polymers (ST-VPDMS) were synthesized by the oxyfunctionalization re- action of the silane. The reaction was found to proceed efficiently and quantitatively. Miscibility studies indicated that about 4 molpercnt; of 4-vin- ylphenyldimethylsilanol (VPDMS) functional group in the copolymer could achieve miscibility with poly(n-butyl methacrylate) (PBMA) and poly(N-vinylpyrrolidone) (PVPr). However, for copolymers containingmore than 34 molpercnt; VPDMS, their blends with PBMA were immiscible. The observed miscibility window of ST-VPDMS/PBMA blends was as- cribed to the competition between the self-association of dimethylsilanol groups and intermolecular hydrogen bonding of dimethylsilanol groups with the carbonyl groups of PBMA. A comparison of the efficiency of the miscibility enhancement and the miscibility windows of VPDMS, p-(hexafluoro-2-isopropyl) styrene (HFPS), and phenolic-containing polymers was made in terms of such competition. The glass transition behavior of the miscible blends involving VPDMS and HFPS-containing styrene copolymers with PBMA were analyzed by the Schneider equation.     

离聚物及其共混体系的研究3.基于配位络合的增容作用

通过将苯乙烯(S)与少量的甲基丙烯酸(MAA)或马来酸酐(MA)共聚及甲基丙烯酸正丁酯(nBMA)与4-乙烯基吡啶(4-VP)共聚,从而在聚苯乙烯(PS)及聚甲基丙烯酸丁酯(PBMA)链上分别引入了功能基团羧酸基(-CO-OH)、酸酐基(-CO-O-CO-)和吡啶基(-N)。通过与锌盐作用获得相应的离聚物(Ionomer)。用红外光谱(IR)表征了共聚物和离聚物的形成;差热分析(DSC)测定共聚物、离聚物和共混物的玻璃化转变温度(Tg)。研究结果表明,随着共聚物中功能基团含量的增加或者共聚物形成离聚物后,其玻璃化转变温度(Tg)提高了;而共聚物的共混物因羧酸基与吡啶基间的质子转移作用而提高了相容性。特别是在引入Zn~(2+)的共混物中,增容作用十分明显,这可归结于BMAVP中的吡啶基和SMAA-Zn~(2+)(或SMA-Zn~(2+))中的Zn~(2+)间的配位络合作用的贡献。     

Study of the miscibility of poly(styrene-co-4-vinylbenzoic acid) with poly(ethyl methacrylate) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] by inverse gas chromatography

Poly(styrene) is immiscible with poly(ethyl methacrylate). The introduction of a small amount of 4-vinylbenzoic acid units along poly(styrene) chains (PS-VBA) enhanced its miscibility with poly(ethyl methacrylate) (PEMA) or with poly[ethyl methacrylate-co-(2-N,N-dimethylaminoethyl) methacrylate] (PEMA-DAE), as observed from the appearance of a single composition dependent glass transition temperature for each binary system using inverse gas chromatography. The negative values of the apparent polymer-polymer interaction parameter, chi(23)app, determined with different families of molecular probes, for three blend compositions and over a range of temperature confirm quantitatively the miscibility of these blends. The chi(23)app values for PEMA(PS-VBA) and (PEMA-DAE)-(PS-VBA) blends are dependent of the chemical nature of the probes, the temperature and the blend composition.     

Hexafluoro-2-hydroxy-2-propyl-modified polyisoprene blends

Dimensionless equilibrium constants describing the self-association of the hexafluoro-2-alkyl-2-propanol group have been determined from infrared spectroscopic data. Corresponding values of these equilibrium constants for a fully modified polyisoprene containing the hexafluoroisopropanol group (PHFPI) were calculated by taking into account differences in the molar volume of the model and the specific repeat unit of the polymer. Equilibrium constants describing the inter-association of PHFPI with methacrylate, acrylate, and acetoxy type carbonyl groups were obtained from spectroscopic studies of miscible PHFPI blends with poly(n-butyl methacrylate), poly(methyl acrylate), and an ethylene-co-vinyl acetate copolymer containing 70 wt% vinyl acetate. The set of equilibrium constant values were then used to calculate theoretical miscibility windows for the complete range of PHFPI blends with poly(n-alkyl methacrylate)s and four copolymers, ethylene-co-methyl methacrylate, styrene-co-methyl acrylate, ethylene-co-methyl acrylate, and ethylene-co-vinyl acetate. Experimental infrared studies confirm the general validity of the predicted miscibility windows. © 1994 John Wiley & Sons, Inc.     

Interactions in SMA-SAN blends

Styrene/maleic anhydride (SMA) and styrene/acrylonitrile (SAN) copolymers have previously been shown to form miscible blends when the MA and AN contents do not differ too greatly. It is shown here that this is the result of a weak exothermic interaction between the MA and AN units by measuring the heats of mixing for appropriate liquid analogs of the various monomer units. The region of copolymer compositions for miscibility of SMA-SAN blends is predicted from the Sanchez-Lacombe mixture theory using net interaction parameters calculated from the analog calorimetry results via a simple binary interaction model for copolymers. Lower critical solution temperature behavior was observed for blends of copolymers having compositions near the edge of the miscibility region. Various glass transition, volumetric, and FTIR results are discussed in terms of the interactions observed.     

Blends of poly(vinyl methyl ether) with styrenic copolymers

Blends of poly(vinyl methyl ether) (PVME) with styrene/acrylonitrile (SAN), with styrene/maleic anhydride (SMA), and with styrene/acrylic acid (SAA) copolymers were examined for glass transition and lower critical solution temperature behavior. These copolymers were found to be completely miscible with PVME at levels of 3% or less of AA; below 10–11% AN, and below 15% MA (w%). Small amounts of the comonomers raised the temperature at which blends with PVME undergo phase separation on heating. This effect was greatest in the order AA > AN > MA. An interpretation of these results is given in terms of recent theories for homopolymer-copolymer blends, and the extent to which solubility parameter theory can be useful is considered.     

Miscibility of poly(styrene‐co‐butyl acrylate) with poly(ethyl methacrylate): Existence of both UCST and LCST

A miscible homopolymer–copolymer pair viz., poly(ethyl methacrylate) (PEMA)–poly(styrene‐co‐butyl acrylate) (SBA) is reported. The miscibility has been studied using differential scanning calorimetry. While 1 : 1 (w/w) blends with SBA containing 23 and 34 wt % styrene (ST) become miscible only above 225 and 185 °C respectively indicating existence of UCST, those with SBA containing 63 wt % ST is miscible at the lowest mixing temperature (i.e., T_g's) but become immiscible when heated at ca 250 °C indicating the existence of LCST. Miscibility for blends with SBA of still higher ST content could not be determined by this method because of the closeness of the T_g's of the components. The miscibility window at 230 °C refers to the two copolymer compositions of which one with the lower ST content is near the UCST, while the other with the higher ST content is near the LCST. Using these compositions and the mean field theory binary interaction parameters between the monomer residues have been calculated. The values are χ_ST‐BA = 0.087 and χ_EMA‐BA = 0.013 at 230 °C. © 2000 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 38: 369–375, 2000     

Synthesis of Poly(Styrene)-block-poly(methacrylate)-block-poly(styrene) via Site Transformation Reaction

Abstract

Triblock copolymers with polystyrene outer blocks and an inner polymethacrylate block were synthesized by a site transformation reaction using anionic and cationic polymerization techniques. In order to obtain such ABA block copolymers, two synthetic routes have been applied. In the first case, different methacrylates (methyl methacrylate, 2-ethylhexyl methacrylate) were polymerized anionically with a bifunctional initiator to get poly(methacrylate) dianions later forming the inner block whereas in the second case poly(styrene)-block-poly(methacrylate) anions were synthesized by monofunctional initiation via sequential monomer addition. In a subsequent step, the living chain ends of the methacrylate dianions on one side, and the diblock copolymer anions on the other side, were functionalized with 1,4-bis(l-bromoethyl)benzene in order to obtain a potential bifunctional or monofunctional macroinitiator for the cationic polymerization of styrene. Then, styrene was polymerized cationically with the macroinitiator in the presence of SnCl₄ as coinitiator and _n Bu₄NBr as a common ion salt in CH₂Cl₂ at -15°C. Block formation was proven by SEC measurements, preparative SEC and NMR characterization.     

由特殊相互作用导致的高分子间的络合

采用结合物理老化技术的示差扫描量热法（ＤＳＣ）以及非辐射能量转移荧光光谱法（ＮＲＥＴ）研究了聚（聚乙烯－ｃｏ－４－乙烯基苯酚与聚甲基丙烯酸乙酯（ＰＥＭＡ）共混体系的相容与络合行为。对ＳＴＶＰｈ／ＰＥＭＡ共混体系,当ＳＴＶＰｈ中的ＯＨ基团含量仅为１ｍｏｌ％时,即可实现相容。随ＯＨ基含量继续增加,共混体系的Ｔｇ值上升并逐渐接近和高于Ｆｏｘ方程计算值,玻璃化转变区域逐渐变窄,ＮＲＥＴ能量转移效率远高于普     

Hyperbranched polymers with maleic functional groups as radical crosslinkers

The crosslinking performance of the unsaturated hyperbranched polyester poly(allyloxy maleic acid‐co‐maleic anhydride) (MAHP) was investigated with copolymerizations of three different monomers: styrene, vinyl acetate, and methyl methacrylate. Both styrene and vinyl acetate afforded interpenetrating‐polymer‐network copolymer gels. The gels exhibited crosslink density gradients through the polymer matrices on a macroscopic level, and density maximums were concentrated around the MAHP moieties. The heterogeneity of the gels is briefly discussed in terms of a modified two‐phase model, where one phase consists of an elastic part of low crosslinking density and the other phase consists of an inelastic dendritic part with a highly condensed bond density. Unlike the two‐phase model developed by Choquet and Rietsch, the modified two‐phase model takes into account that both phases swell in good solvents. Unlike copolymerizations employing styrene or vinyl acetate, the copolymerization of MAHP with methyl methacrylate afforded noncrosslinked starbranched copolymers that consisted of a MAHP core from which long poly(methyl methacrylate) branches were protruding. The different behaviors of the copolymerizations of the three monomers used in this study can rationally be explained by their different reactivity ratios with maleic end groups of MAHP. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 964–972, 2001     

Phase separation of off‐critical polymer blends of poly(styrene‐co‐maleic anhydride) and poly(methyl methacrylate). II. Morphology and mechanical properties

The effects of the phase‐separation temperature and time on the mechanical properties and morphology of poly(methyl methacrylate)/poly(styrene‐co‐maleic anhydride with 10 wt% ethyl acrylate) (SMA) blends were studied. Two compositions (20/80 and 40/60 w/w SMA/PMMAe) were prepared with a miniature twin‐screw extruder. Compared with those of the miscible blends, the Young's modulus values of the blends increased after the phase separation of the 40/60 SMA/PMMAe blend and within the early stage of spinodal decomposition of the 20/80 SMA/PMMAe blend. The mechanical properties, in terms of the tensile strength at break and the elongation, were better for the miscible blends than for the phase‐separation blends. This was believed to be the result of changes in the composition and molecular reorganization. The changes in the phase‐separating domains of both compositions, as observed by transmission electron microscopy, had no significant influence on the tensile moduli. Detailed studies of the morphology revealed a cocontinuous structure, indicating that the blends underwent spinodal decomposition. A morphological comparison of the two compositions illustrated the validity of the level rule. The growth rate of the droplet size was determined by approximation from the light scattering data and by direct measurements with transmission electron microscopy. The discrepancies observed in the droplet size growth rate were attributed to heat variations induced by the different sample thicknesses and heat transfer during the investigation. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 886–897, 2004     

Miscibility study in the blends of novel poly (styrene-co-4-vinylphenyldimethylsilanol) and poly (n-butyl methacrylate)

The miscibility of poly (styrene-co-4-vinylphenyldimethylsilanol) (ST-VPDMS) and poly (n-butyl methacrylate) (PBMA) blends has been investigated by means of DSC and FT-IR spectroscopy. It was found that miscible blends were formed only for the copolymers containing 9–34 mol % 4-vinylphenyldimethylsilanol (VPDMS). The glass transition behavior of the miscible blends was analyzed by recently proposed equations in terms of the physical meaning of the fitting parameters. The results of FT-IR study were found to be fully consistent with the observation of the miscibility window obtained from glass transition temperature measurements. Quantitative information concerning intermolecular hydrogen bond interaction in the carbonyl stretching vibration region of the miscible blends was obtained by curve-fitting method. © 1994 John Wiley & Sons, Inc.     

Copolymerization of 2-phenylvinyl alkyl ethers and maleic anhydride

A series of 2-phenylvinyl alkyl ethers (I) having as alkyl group methyl, ethyl, n-propyl, n-butyl, 2-methylbutyl, 3-methylpentyl, and optically active 1-methylpropyl of (S) absolute configuration, were copolymerized with maleic anhydride to alternating copolymers. The copolymerizations were carried out in bulk at 70°C in the presence of AIBN as initiator. Monomer I (R = Et) was also polymerized with lauroyl and benzoyl peroxide as initiator. The yield and molecular weight were highest when equimolar amounts of both monomers were used. The equilibrium constant of charge-transfer complex of monomer I (R = Et) and maleic anhydride was determined by the transformed Benessi-Hildebrand NMR method and has a value of 0.28 mole/1.