Miscible blends containing bacterial poly(3‐hydroxyvalerate) and poly(p‐vinyl phenol)

The miscibility of poly(3‐hydroxyvalerate) (PHV)/poly(p‐vinyl phenol) (PVPh) blends has been studied by differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. The blends are miscible as shown by the existence of a single glass transition temperature (T_g) and a depression of the equilibrium melting temperature of PHV in each blend. The interaction parameter was found to be −1.2 based on the analysis of melting point depression data using the Nishi–Wang equation. Hydrogen‐bonding interactions exist between the carbonyl groups of PHV and the hydroxyl groups of PVPh as evidenced by FTIR spectra. The crystallization of PHV is significantly hindered by the addition of PVPh. The addition of 50 wt % PVPh can totally prevent PHV from cold crystallization. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 383–388, 1999     

Small‐molecule‐induced miscibility of isosorbide‐based polycarbonate with bisphenol A polycarbonate

In this study, we investigated the influence of the small molecule 4,4′‐thiobis(6‐tert‐butyl‐m‐methyl phenol) (AO300) on the miscibility of poly(isosorbide‐co‐1,4‐cyclohexanedimethanol carbonate) (IcC–PC) with bisphenol A polycarbonate (BPA–PC) through the formation of hydrogen‐bonding networks. Differential scanning calorimetry and morphological observation revealed that the initially, immiscible BPA–PC/IcC–PC blends become miscible through the addition of small molecules. Fourier transform infrared spectroscopy confirmed that intermolecular hydrogen bonds formed between the hydroxyl groups of AO300 and the carbonyl groups of the studied polycarbonates. These polycarbonates exhibited different hydrogen‐bonding behaviors and various degrees of glass‐transition temperature composition dependence. Dynamic mechanical analysis demonstrated that AO300 played an antiplasticization role in the BPA–PC/IcC–PC blends with improved storage moduli. To our knowledge, this article is the first to describe the miscibility of isosorbide‐based polycarbonate with BPA–PC. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44537.     

Isothermal crystallization kinetics in binary miscible blend of poly(ε‐caprolactone)/tetramethyl polycarbonate

The crystallization kinetics of pure poly(ε‐caprolactone) (PCL) and its blends with bisphenol‐A tetramethyl polycarbonate (TMPC) was investigated isothermally as a function of composition and crystallization temperature (T_c) using differential scanning calorimetric (DSC) and polarized optical microscope techniques. Only a single glass‐transition temperature, T_g, was determined for each mixture indicating that this binary blend is miscible over the entire range of composition. The composition dependence of the T_g for this blend was well described by Gordon–Taylor equation with k = 1.8 (higher than unity) indicating strong intermolecular interaction between the two polymer components. The presence of a high T_g amorphous component (TMPC) had a strong influence on the crystallization kinetics of PCL in the blends. A substantial decrease in the crystallization kinetics was observed as the concentration of TMPC rose in the blends. The crystallization half‐time t_0.5 increased monotonically with the crystallization temperature for all composition. At any crystallization temperature (T_c) the t_0.5 of the blends are longer than the corresponding value for pure PCL. This behavior was attributed to the favorable thermodynamics interaction between PCL and TMPC which in turn led to a depression in the equilibrium melting point along with a simultaneous retardation in the crystallization of PC. The isothermal crystallization kinetics was analyzed on the basis of the Avrami equation. Linear behavior was held true for the augmentation of the radii of spherulites with time for all mixtures, regardless of the blend composition. However, the spherulites growth rate decreased exponentially with increasing the concentration of TMPC in the blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3307–3315, 2007     

Miscibility of DMPC‐TMPC copolycarbonate/SMMA copolymer blends and their interaction energies of binary pairs involved in blends

The isothermal miscibility map and phase‐separation temperatures caused by lower critical solution temperature‐type phase behavior for blends of poly[2,2,‐propane‐bis{4‐(2‐methyl phenyl)} carbonate]‐poly[2,2,‐propane‐bis{4‐(2,6‐dimethyl phenyl)} carbonate] (DMPC‐TMPC) with poly[(styrene)‐co‐(methyl methacrylate)] (SMMA) copolymers have been determined. SMMA copolymers containing equal to or less than 37 wt% MMA formed miscible blends with DMPC‐TMPC copolycarbonates containing equal to or more than 60 wt% TMPC. The observed phase‐separation temperatures indicate that the miscibility decreases as the DMPC content in DMPC‐TMPC increases, while addition of MMA to the styrene initially increases miscibility with DMPC‐TMPC but ultimately leads to immiscibility. The binary interaction energies involved in these blends were calculated from the phase boundaries using the lattice‐fluid theory combined with the binary interaction model. The spinodal temperatures predicted from the lattice‐fluid theory using the calculated interaction energies are similar to the experimental phase‐separation temperatures. Copyright © 2004 Society of Chemical Industry     

Binary and ternary polymer blends containing poly(vinylidene chloride‐co‐acrylonitrile)

Poly(vinylidene chloride‐co‐acrylonitrile) (Saran F), poly(hydroxy ether of bisphenol A) (phenoxy), poly(styrene‐co‐acrylonitrile) (PSAN), and poly(vinyl phenol) (PVPh) all have the same characteristic: miscibility with atactic poly(methyl methacrylate) (aPMMA). However, the miscibility of Saran F with the other polymer (phenoxy, PSAN, or PVPh) is not guaranteed and was thus investigated. Saran F was found to be miscible only with PSAN but not miscible with phenoxy and PVPh. Because Saran F and PVPh are not miscible, although they are both miscible with aPMMA, aPMMA can thus be used as a potential cosolvent to homogenize PVPh/Saran F. The second part of this report focused on the miscibility of a ternary blend consisting of Saran F, PVPh, and aPMMA to investigate the cosolvent effect of aPMMA. Factors affecting the miscibility were studied. The established phase diagram indicated that the ternary blends with high PVPh/Saran F weight ratio were found to be mostly immiscible. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3068–3073, 2004     

Effects of tetramethylpolycarbonate‐block‐poly(styrene‐co‐acrylonitrile) copolymers containing various amounts of acrylonitrile on the interfacial properties of polycarbonate and poly(styrene‐co‐acrylonitrile) blends

Tetramethylpolycarbonate‐block‐poly(styrene‐co‐acrylonitrile) (TMPC‐block‐SAN) block copolymers containing various amounts of acrylonitrile (AN) were examined as compatibilizers for blends of polycarbonate (PC) with poly(styrene‐co‐acrylonitrile) (SAN) copolymers. To explore the effects of block copolymers on the compatibility of PC/SAN blends, the average diameter of the dispersed particles in the blend was measured with an image analyzer, and the interfacial properties of the blends were analyzed with an imbedded fibre retraction technique and an asymmetric double‐cantilever beam fracture test. Reduction in the average diameter of dispersed particles and effective improvement in the interfacial properties was observed by adding TMPC‐block‐SAN copolymers as compatibilizer of PC/SAN blend. TMPC‐block‐SAN copolymer was effective as a compatibilizer when the difference in the AN content of SAN copolymer and that of SAN block in TMPC‐block‐SAN copolymer was less than about 10 wt%. Copyright © 2004 Society of Chemical Industry     

The totally miscible in ternary hydrogen‐bonded polymer blend of poly(vinyl phenol)/phenoxy/phenolic

The individual binary polymer blends of phenolic/phenoxy, phenolic/poly(vinyl phenol) (PVPh), and phenoxy/PVPh have specific interaction through intermolecular hydrogen bonding of hydroxyl–hydroxyl group to form homogeneous miscible phase. In addition, the miscibility and hydrogen bonding behaviors of ternary hydrogen bond blends of phenolic/phenoxy/PVPh were investigated by using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy, and optical microscopy. According to the DSC analysis, every composition of the ternary blend shows single glass transition temperature (T_g), indicating that this ternary hydrogen‐bonded blend is totally miscible. The interassociation equilibrium constant between each binary blend was calculated from the appropriate model compounds. The interassociation equilibrium constant (K_A) of each individually binary blend is higher than any self‐association equilibrium constant (K_B), resulting in the hydroxyl group tending to form interassociation hydrogen bond. Photographs of optical microscopy show this ternary blend possess lower critical solution temperature (LCST) phase diagram. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of tacticity of poly(methyl methacrylate) on the miscibility with poly(styrene‐co‐acrylonitrile)

Isotactic, atactic, and syndiotactic poly(methyl methacrylates) (PMMAs) (designated as iPMMA, aPMMA, and sPMMA) with approximately the same molecular weight were mixed separately with poly(styrene‐co‐acrylonitrile) (abbreviated as PSAN) containing 25 wt % of acrylonitrile in tetrahydrofuran to make three polymer blend systems. Differential scanning calorimetry (DSC) was used to study the miscibility of these blends. The results showed that the tacticity of PMMA has a definite impact on its miscibility with PSAN. The aPMMA/PSAN and sPMMA/PSAN blends were found to be miscible because all the prepared films were transparent and showed composition dependent glass transition temperatures (T_gs). The glass transition temperatures of the two miscible blends were fitted well by the Fox equation, and no broadening of the glass transition regions was observed. The iPMMA/PSAN blends were found to be immiscible, because most of the cast films were translucent and had two glass transition temperatures. Through the use of a simple binary interaction model, the following comments can be drawn. The isotactic MMA segments seemed to interact differently with styrene and with acrylonitrile segments from atactic or syndiotactic MMA segments. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 2894–2899, 1999     

Miscibility and intermolecular hydrogen‐bonding interactions in poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)/poly(4‐vinyl phenol) binary blends

The miscibility and hydrogen bonding interaction in the poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate)/poly(4‐vinyl phenol) [P(3HB‐co‐3HH)/PVPh] binary blends were investigated by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The DSC results indicate that P(3HB‐co‐3HH) with 20 mol % 3HH unit content is fully miscible with PVPh, and FTIR studies reveal the existence of hydrogen bonding interaction between the carbonyl groups of P(3HB‐co‐3HH) and the hydroxyl groups of PVPh. The effect of blending of PVPh on the mechanical properties of P(3HB‐co‐3HH) were studied by tensile testing. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Melt‐state miscibility of poly(ethylene‐co‐1‐octene) and linear polyethylene

On purpose to examine the effect of branch length on the miscibility of polyolefin blends, miscibility behavior of linear polyethylene/poly(ethylene‐co‐1‐octene) blend was studied and compared to that of linear polyethylene/poly(ethylene‐co‐1‐butene) blend. Miscibility of the blend was determined by observing the morphology quenched from the melt, and by using the relation between interaction parameter and copolymer composition. When the weight composition and molecular weight was the same, poly(ethylene‐co‐1‐octene) was slightly more miscible with linear polyethylene than poly(ethylene‐co‐1‐butene) was. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Ionically Cross‐Linked Proton Conducting Membranes for Fuel Cells

For improving stability without sacrificing ionic conductivity, ionically cross‐linked proton conducting membranes are fabricated from Na⁺‐form sulfonated poly(phthalazinone ether sulfone kentone) (SPPESK) and H⁺‐formed sulfonated poly(2,6‐dimethyl‐1,4‐phenylene oxide) (SPPO). Ionically acid‐base cross‐linking between sulfonic acid groups in SPPO and phthalazone groups in SPPESK impart the composite membranes the good miscibility and electrochemical performance. In particular, the composite membranes possess proton conductivity of 60–110 mS cm⁻¹ at 30 °C. By controlling the protonation degree of SPPO within 40–100 %, the composite membranes with favorable cross‐linking degree are qualified for application in fuel cells. The maximum power density of the composite membrane reaches approximately 1100 mW cm⁻² at the current density of 2800 mA cm⁻² at 70 °C.     

Properties and pervaporation characteristics of chitosan–poly(N‐vinyl‐2‐pyrrolidone) blend membranes for MeOH–MTBE

Clear blends of chitosan with poly(N‐vinyl‐2‐pyrrolidone) (PVP) made from aqueous solutions appear to be miscible from visual appearance. Infrared (IR) spectra used to investigate the carbonyl—hydroxyl hydrogen bonding in the blends indicated compatibility of two polymers on a molecular level. The IR spectra were also used to determine the interaction change accessing with increasing temperature and indicated that a significant conformational change occurred. On the other hand, the blend membranes were evaluated for separation of methanol from methyl tert‐butyl ether. The influences of the membrane and the feed compositions were investigated. Methanol preferentially permeates through all the tested membranes, and the partial flux of methanol significantly increase with the poly(N‐vinyl‐2‐pyrrolidone) content increasing. The temperature dependence of pervaporation performance indicated that a significant conformational change occurred with increasing temperature. Combined with the IR results, the pervaporation properties are in agreement with characteristics of interaction between chain–chain within the blend membranes. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1452–1458, 1999     

The study of poly(styrene‐co‐p‐(hexafluoro‐2‐hydroxylisopropyl)‐α‐methylstyrene)/poly(ethylene oxide) blends

Different hydroxyl content poly(styrene‐co‐p‐(hexafluoro‐2‐hydroxylisopropyl)‐α‐methylstyene) [PS(OH)‐X] copolymers were synthesized and blends with 2,2,6,6‐tetramrthyl‐piperdine‐1‐oxyl end spin‐labeled PEO [SLPEO] were prepared. The miscibility behavior of all the blends was predicted by comparing the critical miscible polymer–polymer interaction parameter (χ_crit) with the polymer–polymer interaction parameter (χ). The micro heterogeneity, chain motion, and hydrogen bonding interaction of the blends were investigated by the ESR spin label method. Two spectral components with different rates of motion were observed in the ESR composite spectra of all the blends, indicating the existence of microheterogeneity at the molecular level. According to the variations of ESR spectral parameters T_a, T_d, ΔT, T_50G and τ_c, with the increasing hydroxyl content in blends, it was shown that the extent of miscibility was progressively enhanced due to the controllable hydrogen bonding interaction between the hydroxyl in PS(OH) and the ether oxygen in PEO. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2312–2317, 2004     

Interpolymer‐specific interactions and miscibility in poly(styrene‐co‐acrylic acid)/poly(styrene‐co‐N,N‐dimethylacrylamide) blends

The miscibility or complexation of poly(styrene‐co‐acrylic acid) containing 27 mol % of acrylic acid (SAA‐27) and poly(styrene‐co‐N,N‐dimethylacrylamide) containing 17 or 32 mol % of N,N‐dimethylacrylamide (SAD‐17, SAD‐32) or poly(N,N‐dimethylacrylamide) (PDMA) were investigated by different techniques. The differential scanning calorimetry (DSC) analysis showed that a single glass‐transition temperature was observed for all the mixtures prepared from tetrahydrofuran (THF) or butan‐2‐one. This is an evidence of their miscibility or complexation over the entire composition range. As the content of the basic constituent increases as within SAA‐27/SAD‐32 and SAA‐27/PDMA, higher number of specific interpolymer interactins occurred and led to the formation of interpolymer complexes in butan‐2‐one. The qualitative Fourier transform infrared (FTIR) spectroscopy study carried out for SAA‐27/SAD‐17 blends revealed that hydrogen bonding occurred between the hydroxyl groups of SAA‐27 and the carbonyl amide of SAD‐17. Quantitative analysis carried out in the 160–210°C temperature range for the SAA‐27 copolymer and its blends of different ratios using the Painter–Coleman association model led to the estimation of the equilibrium constants K₂, K_A and the enthalpies of hydrogen bond formation. These blends are miscible even at 180°C as confirmed from the negative values of the total free energy of mixing ΔG_M over the entire blend composition. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 1011–1024, 2007     

Miscible blends of poly(4‐vinyl phenol)/poly (trimethylene terephthalate)

A new miscible blend of all compositions comprising poly(4‐vinyl phenol) (PVPh) and poly(trimethylene terephthalate) (PTT) was discovered and reported. The blends exhibit a single composition‐dependent glass transition and homogeneous phase morphology, with no lower critical solution temperature (LCST) behavior upon heating to high temperatures. Interactions and spherulite growth kinetics in the blends were also investigated. The Flory–Huggins interaction parameter (χ₁₂) and interaction energy density (B) obtained from analysis of melting point depression are negative (χ₁₂ = ?0.74 and B = ?32.49 J cm^?3), proving that the PVPh/PTT blends are miscible over a wide temperature range from ambient up to high temperatures in the melt state. FTIR studies showed evidence of hydrogen‐bonding interactions between the two polymers. The miscibility of PVPh with PTT also resulted in a reduction in spherulite growth rate of PTT in the miscible blend. The Lauritzen–Hoffman model was used to analyze the spherulite growth kinetics, which showed a lower fold‐surface free energy (σ_e) of the blends than that of the neat PTT. The decrease in the fold‐surface free energy has been attributed to disruption of the PTT lamellae exerted by PVPh in an intimately interacted miscible state. Copyright © 2004 Society of Chemical Industry     

Interpolymer interactions and miscibility in poly(n‐butyl methacrylate‐co‐methacrylic acid)/poly(styrene‐co‐N,N‐dimethyl acrylamide) blends

The miscibility of poly(n‐butyl methacrylate‐co‐methacrylic acid) containing 18 mol % methacrylic acid (BMAM‐18) and poly(styrene‐co‐N,N‐dimethyl acrylamide) containing 17 mol % N,N‐dimethyl acrylamide (SAD‐17) was investigated with viscometry, differential scanning calorimetry (DSC), and Fourier transform infrared (FTIR) spectroscopy. The DSC analysis showed a single glass‐transition temperature for all the blends, indicating that these copolymers were miscible over the entire composition range. The glass‐transition temperatures of these blends were higher than those calculated with the additivity rule. This was characteristic of the presence of specific interactions. The interactions between BMAM‐18 and the tertiary amide of SAD‐17 were studied with FTIR spectroscopy, which revealed that hydrogen‐bonding interactions occurred between the hydroxyl groups of BMAM‐18 and the carbonyl amide of SAD‐17. A new band characterizing these interactions appeared around 1613 cm^?1. The quantitative results showed that the fraction of the associated amide increased with an increase in the amount of the acidic BMAM‐18 copolymer. Although BMAM‐18 and SAD‐17 led to homogeneous solutions in butan‐2‐one, as the concentration of N,N‐dimethyl acrylamide increased to 32 mol % [as within the poly(styrene‐co‐N,N‐dimethyl acrylamide) containing 32 mol % N,N‐dimethyl acrylamide], complexation occurred when this latter compound was mixed with BMAM‐18 in butan‐2‐one. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2717–2724, 2006     

Miscibility of copolycarbonate blends with poly(styrene-co-acrylonitrile) copolymer and their interaction energies

The phase behavior of dimethyl polycarbonate-tetramethyl polycarbonate (DMPC-TMPC) blends with poly(styrene-co-acrylonitrile) copolymers (SAN) and the interaction energies of binary pairs involved in blend has been explored. DMPC-TMPC copolycarbonates containing 60 wt% TMPC or more were formed miscible blends with SAN containing limited amounts of AN. The miscibility of copolycarbonate with SAN decreases as the DMPC content increases. The miscible blends showed the LCST-type phase behavior or did not phase separate until thermal degradation. The binary interaction energies involved in the miscible blends were calculated from the phase boundaries using the lattice-fluid theory combined with binary interaction model. The phenyl ring substitution with methyl groups did not lead to interactions that are favorable for miscibility with polyacrylonitrile (PAN). The interaction energies of the polycarbonates blends with SAN copolymers as a function of AN content were obtained. It was revealed that the incline of the number of methyl groups on the phenyl rings of bisphenol-A unit acts favorably for the miscibility with SAN copolymer when SAN contains less than about 30 wt% AN and shifts the most favorable interaction to the low AN content.     

Phase behavior of ternary blends containing dimethylpolycarbonate,tetramethylpolycarbonate and poly[styrene‐co‐(methyl methacrylate)] copolymers (or polystyrene)

The miscibility and phase behavior of ternary blends containing dimethylpolycarbonate (DMPC), tetramethylpolycarbonate (TMPC) and poly[styrene‐co‐(methyl methacrylate)] copolymer (SMMA) have been explored. Ternary blends containing polystyrene (PS) instead of SMMA were also examined. Blends of DMPC with SMMA copolymers (or PS) did not form miscible blends regardless of methyl methacrylate (MMA) content in copolymers. However, DMPC blends with SMMA (or PS) blends become miscible by adding TMPC. The miscible region of ternary blends is compared with the previously determined miscibility region of binary blends having the same chemical components and compositions. The region where the ternary blends are miscible is much narrower than that of binary blends. Based on lattice fluid theory, the observed phase behavior of ternary blends was analyzed. Even though the term representing the Gibbs free energy change of mixing for certain ternary blends had a negative value, blends were immiscible. It was revealed that a negative value of the Gibbs free energy change of mixing was not a sufficient condition for miscible ternary blends because of the asymmetry in the binary interactions involved in ternary blends. Copyright © 2004 Society of Chemical Industry     

Specific interactions in miscible polymer blends of poly(2‐hydroxypropyl methacrylate) with polyvinylpyrrolidone

The miscibility behaviour and hydrogen‐bonding interaction in blends of poly(2‐hydroxypropyl methacrylate) (PHPMA) with polyvinylpyrrolidone (PVP) were characterized using differential scanning calorimetry and Fourier‐transform infrared spectra. This polymer blend was miscible over the whole composition range and an unusually large positive deviation of T_g from the linearity rule was observed, indicating strong hydrogen bonding between the hydroxyl group of PHPMA and the carbonyl group of PVP. Infrared spectroscopic analysis provided positive evidence for the intra‐molecular hydrogen bonding of PHPMA and inter‐molecular hydrogen bonding between PHPMA and PVP at various compositions and temperatures. Furthermore, equilibrium constants and enthalpies of self‐association and inter‐association between functional groups in the blend of PHPMA and PVP were calculated to explain the results. Copyright © 2004 Society of Chemical Industry     

Effect of bisphenol A on the miscibility,phase morphology,and specific interaction in immiscible biodegradable poly(ε‐caprolactone)/poly(L‐lactide) blends

We have investigated the enhancement in miscibility, upon addition of bisphenol A (BPA) of immiscible binary biodegradable blends of poly(ε‐caprolactone) (PCL) and poly(L ‐lactide) (PLLA). That BPA is miscible with both PCL and PLLA was proven by the single value of T_g observed by differential scanning calorimetry (DSC) analyses over the entire range of compositions. At various compositions and temperatures, Fourier transform infrared spectroscopy confirmed that intermolecular hydrogen bonding existed between the hydroxyl group of BPA and the carbonyl groups of PCL and PLLA. The addition of BPA enhances the miscibility of the immiscible PCL/PLLA binary blend and transforms it into a miscible blend at room temperature when a sufficient quantity of the BPA is present. In addition, optical microscopy (OM) measurements of the phase morphologies of ternary BPA/PCL/PLLA blends at different temperatures indicated an upper critical solution temperature (UCST) phase diagram, since the ΔK effect became smaller at higher temperature (200°C) than at room temperature. An analysis of infrared spectra recorded at different temperatures correlated well with the OM analyses. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1146–1161, 2006