Miscibility of segmented polyurethane/poly(vinyl chloride) blends

Miscibilities of segmented polyurethanes (SPUs) and poly(vinyl chloride) (PVC) or functionalized poly(vinyl chloride) (FPVC) were studied with dynamic mechanical analysis, differential scanning calorimetry, and X‐ray diffraction. Mechanical properties of the blends were also studied with tensile measurements. The miscibility of the blends depended greatly on the hard‐segment content of SPU and the existence of the functional groups. The combination of SPU with a low hard‐segment content and PVC with functional groups made the blend system miscible. Moreover, controlling the blend composition of SPU/FPVC allowed us to modify the mechanical properties of SPU, where the elongation at break was multiplied without a significant change in its tensile strength. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3022–3029, 2001     

Miscibility and thermal behavior of poly(vinyl chloride)/feather keratin blends

Various poly(vinyl chloride) (PVC)/feather keratin (FK) blends were prepared via a solution blending method in the presence of N,N‐dimethylformamide as a solvent. The miscibility of the blends was studied with different analytical methods, such as dilute solution viscometry, differential scanning calorimetry, refractometry, and atomic force microscopy. According to the results obtained from these techniques, it was concluded that the PVC/FK blend was miscible in all the studied compositions. Specific interactions between carbonyl groups of the FK structure and hydrogen from the chlorine‐containing carbon of the PVC were found to be responsible for the observed miscibility on the basis of Fourier transform infrared spectroscopy. Furthermore, increasing the FK content in the blends resulted in their miscibility enhancement. The thermal stability of the samples, as an important characteristic of biobased polymer blends, was finally examined in terms of their FK weight percentage and application temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Miscibility of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(vinyl chloride) blends

The miscibility behaviour of biodegradable poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHB-HV) blended with poly(vinyl chloride) (PVC) was investigated by using differential scanning calorimetry, dynamic mechanical thermal analysis, Fourier-transform infra-red spectroscopy and a mechanical testing system. A blend of PHB-HV containing 8% HV (PHB-8HV) with PVC was immiscible, showing two separate T_g values in all compositions: whereas a blend of PHB-HV containing 18% HV (PHB-18HV) with PVC was miscible, showing a melting-point depression and a single T_g in the whole range of compositions. For the PHB-18HV/PVC system, the C-O-C stretching vibration at 1183 cm⁻¹ of PHB-18HV and the CHCl deformation at 1254cm⁻¹ of PVC were shifted, indicating that there exists a specific intermolecular interaction between the two components. In addition, as the PVC component was increased, tensile strength and Young's modulus were increased, while the inverse behaviour was observed in elongation at break.     

环氧树脂增强聚氯乙烯/丁腈橡胶共混胶的性能

用环氧树脂(EP)增强聚氯乙烯/丁腈橡胶(PVC/NBR)共混胶,研究了EP用量对共混胶力学性能的影响,考察了EP对炭黑增强PVC/NBR共混胶力学性能的影响,并用扫描电子显微镜分析了共混胶的微观形貌。结果表明,用EP增强PVC/NBR共混胶,胶料的力学性能提高,且老化后性能变化不明显。在EP用量为18份左右时共混胶的综合性能最佳。EP对炭黑增强PVC/NBR共混胶力学性能的改善有一定作用。EP在PVC/NBR共混胶中原位聚合生成了直径约为200 nm的纤维。     

Miscibility and mechanical properties of poly(ether imide)/poly(ether ether ketone)/liquid crystalline polymer ternary blends

This paper is concerned with a novel ternary blend composed of poly(ether imide) (PEI), poly(ether ether ketone) (PEEK) and a liquid crystalline polymer (LCP; HX4000, Du Pont). Different compositions were prepared by extrusion and injection moulding. Dynamic mechanical thermal analysis and the observation of the fracture surfaces, before and after annealing, allowed determination of the cold crystallization temperatures and miscibility behaviour of these systems. PEEK/PEI blends are known from previous studies to be miscible at all compositions. In this case it was observed that the PEEK/HX4000 blend was miscible up to 50 wt% HX4000 but partially miscible above this value. The PEI/HX4000 blends were found to be partially miscible in the whole concentration range. As a result, some ternary blend compositions exhibited only one phase, while others exhibited two phases. The measurement of the tensile properties showed that ternary blends with high modulus can be obtained at high LCP loadings, while compositions with high ultimate tensile strength can be obtained with high loadings of PEI or PEEK.     

Miscibility and rheological properties of poly(vinyl chloride)/styrene–acrylonitrile blends prepared by melt extrusion

Styrene–acrylonitrile (SAN) with acrylonitrile (AN) concentrations of 11.6–26 wt % and α‐methylstyrene acrylonitrile (αMSAN) with a wide range of AN concentrations are miscible with poly(vinyl chloride) (PVC) through solution blending. Here we examine the rheological properties and miscibility of PVC/SAN and PVC/αMSAN blends prepared by melt extrusion for commercial applications. We have investigated the rheological properties of the blends with a rheometer and a melt indexer. The PVC/SAN and PVC/αMSAN blends have a low melting torque, a long degradation time, and a high melt index, and this means that they have better processability than pure PVC. The miscibility of the blends has been characterized with differential scanning calorimetry, dynamic mechanical thermal analysis, and advanced rheometrics expansion system analysis. The miscibility of the blends has also been characterized with scanning electron microscopy. The SAN series with AN concentrations of 24–31 wt % is immiscible with PVC by melt extrusion, whereas αMSAN with 31 wt % AN is miscible with PVC, even when they are blended by melt extrusion, because of the strong interaction between PVC and αMSAN. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Miscibility,phase behavior,and mechanical properties of ternary blends of poly(vinyl chloride)/polystyrene/chlorinated polyethylene-graft-polystyrene

The effectiveness of chlorinated polyethylene-graft-polystyrene (CPE-g-PS) as a polymeric compatibilizer for immiscible poly(vinyl chloride)/polystyrene (PVC/PS) blends was investigated. The miscibility, phase behavior, and mechanical properties were studied using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), Izod impact tests, tensile tests, and scanning electron microscopy (SEM). DSC and DMA studies showed that PVC is immiscible with chlorinated polyethylene (CPE) in CPE-g-PS, whereas the PS homopolymer is miscible with PS in CPE-g-PS. The PVC/PS/CPE-g-PS ternary blends exhibit a three-phase structure: PVC phase, CPE phase, and PS phase that consisted of a PS homopolymer and PS in CPE-g-PS. The mechanical properties showed that CPE-g-PS interacts well with both PVC and PS and can be used as a polymeric compatibilizer for PVC/PS blends. CPE-g-PS can also be used as an impact modifier for both PVC and PS. SEM observations confirmed, after the addition of CPE-g-PS, improvement of the interfacial adhesion between the phases of the PVC/PS blends. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 995–1003, 1998     

Electrical properties and transport conduction mechanism of nitrile rubber/poly(vinyl chloride) blend

The current–voltage characteristics of acrylonitrile butadiene rubber (NBR)/poly(vinyl chloride) (PVC) blends are studied as a function of sample temperature and PVC content. These samples showed ohmic behavior up to (225 V), after this value the behavior become SCLC (space charge limited conduction). The results obtained show that the charge carriers are generated by Richardson–Schottky emission from the electrode as well as from trapped ionic impurities at high fields. The activation energy of the prepared samples was calculated by using Arrhenius equation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Thermodynamics of the phase behaviour of poly(vinyl chloride)/aliphatic polyester blends

A series of linear aliphatic polyesters having $\text{CH}{}_2\text{COO}$ ratios in their repeat units from 2 to 14 have been examined for miscibility with poly(vinyl chloride). There is a window of structures in the middle of this spectrum where miscibility is observed. At the low end there is a very sharp boundary lying between $\text{CH}{}_2\text{COO}\text{= 3}$ and 4 dividing the polyesters which are immiscible with PVC from those which are miscible. At the high end the boundary is not so sharp but rather phase separation caused by a lower critical solution temperature occurs at progressively lower temperatures as $\text{CH}{}_2\text{COO}$ increases beyond 10. Thermodynamic interaction parameters for the miscible blends were obtained by analysis of the depression of the polyester melting point after correction for finite crystal thickness using the Hoffman-Weeks method. These results are compared with heats of mixing obtained directly using low molecular weight analogues of the polymers. The two results show very similar trends but are not quantitatively identical for reasons mentioned. A binary interaction model has been used to analyse the heat of mixing data, and it is concluded that there is a strong unfavourable intramolecular interaction between the -CH₂- and -COO- units in aliphatic polyesters which is an important factor in their miscibility with PVC and other polymers.     

Miscibility and thermooxidative degradation of poly(vinyl chloride)/biodegradable aliphatic–aromatic copolyester blends

The miscibility of poly(vinyl chloride) (PVC) and a biodegradable aliphatic–aromatic copolyester (AAC) was investigated by differential scanning calorimetry. The thermooxidative degradation of the blends was investigated thermogravimetrically. The blends were prepared by dissolution in 1,2‐dichloroethane and precipitation with methanol. The investigated blends were completely miscible with the glass‐transition temperatures best predicted by the Fox equation. Fourier transform infrared analysis showed that the interactions responsible for miscibility were the hydrogen bonds between the blend components. The thermooxidative stability of the PVC/AAC blends was improved compared to that of pure PVC. Furthermore, when AAC was added, the dehydrochlorination rate of PVC decreased, and the maximum rate shifted to a higher temperature. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2158–2163, 2006     

Miscibility and melting behavior of poly(ethylene terephthalate)/poly(trimethylene terephthalate) blends

The miscibility and melting behavior of binary crystalline blends of poly(ethylene terephthalate) (PET)/poly(trimethylene terephthalate) (PTT) have been investigated with differential scanning calorimetry and scanning electron microscope. The blends exhibit a single composition‐dependent glass transition temperature (T_g) and the measured T_g fit well with the predicted T_g value by the Fox equation and Gordon‐Taylor equation. In addition to that, a single composition‐dependent cold crystallization temperature (T_cc) value can be observed and it decreases nearly linearly with the low T_g component, PTT, which can also be taken as a valid supportive evidence for miscibility. The SEM graphs showed complete homogeneity in the fractured surfaces of the quenched PET/PTT blends, which provided morphology evidence of a total miscibility of PET/PTT blend in amorphous state at all compositions. The polymer–polymer interaction parameter, χ₁₂, calculated from equilibrium melting temperature depression of the PET component was ?0.1634, revealing miscibility of PET/PTT blends in the melting state. The melting crystallization temperature (T_mc) of the blends decreased with an increase of the minor component and the 50/50 sample showed the lowest T_mc value, which is also related to its miscible nature in the melting state. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Thermal properties of graphite‐loaded nitrile rubber/poly(vinyl chloride) blends

The thermal properties (thermal conductivity, thermal diffusivity, and specific heat capacity) of nitrile rubber (NBR)/poly(vinyl chloride) (PVC) blends were measured in the temperature range of 300–425 K. The incorporation of graphite into the NBR/PVC (30/70) matrix improved its thermal properties. Moreover, these properties slightly changed with the temperature. The thermal conductivity values of the prepared samples were compared with values modeled according to the Maxwell–Eucken, Cheng–Vachon, Lewis–Nielsen, geometric mean, and Agari–Uno models. The Agari–Uno model best predicted the effective thermal conductivity for the whole range of blend ratios and for the whole range of graphite contents in NBR/PVC (30/70)/graphite composites. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

丁腈橡胶/聚氯乙烯/受阻酚AO-60共混物的结构与性能

用差示扫描量热法、X射线衍射法、扫描电子显微镜及元素分析法分析了丁腈橡胶(NBR)/聚氯乙烯(PVC)/四[β-(3,5-二叔丁基-4-羟基苯基)丙酸]季戊四醇酯(AO-60)共混物的结构,并研究了共混物的阻尼性能及力学性能。结果表明,当AO-60用量小于50份时,其分子在基体中以非晶态形式存在;当AO-60用量超过50份时,过量的AO-60形成聚集体并在基体中形成少量的晶体;NBR/PVC/AO-60共混物内部呈现“海相-岛相”结构,连续相主要是NBR,而分散相主要是PVC与AO-60分子。NBR/PVC/AO-60共混物的损耗因子-温度曲线呈双峰特征,且随着AO-60用量的增加,峰值明显增大。当AO-60用量为50份时,NBR/PVC/AO-60共混物的综合力学性能较佳。     

Miscibility and morphology of the poly(vinyl chloride)/styrene-acrylonitrile copolymer/poly(methyl methacrylate) ternary blend system

The phase equilibrium of the ternary system poly (vinyl chloride) (PVC)/styrene-acrylonitrile copolymer (77/23) (SAN)/poly (methyl methacrylate) (PMMA) was investigated using a combination of turbidity, scanning electron microscopy (SEM), and differential scanning calorimetry (DSC) measurements. Both turbidity and DSC were used to determine room temperature ternary phase diagrams. The results are basically similar, but the formulation based on the DSC results and the presumed phase model would seem more reliable since it is possible that immiscible blends may well have different phases with similar refractive indices.     

Miscibility enhancement on the immiscible poly (vinyl pyrrolidone) and poly (ethyl methacrylate) with poly (vinyl phenol)

The miscibility behavior of ternary blends of poly (vinyl phenol) (PVPh)/poly (vinyl pyrrolidone) (PVP)/poly (ethyl methacrylate) (PEMA) was investigated mainly with calorimetry. PVPh is miscible with both PVP and PEMA on the basis of the single T_g observed over the entire composition range. FTIR was used to study the hydrogen bonding interaction between the hydroxyl group of PVPh and the carbonyl group of PVP and PEMA at various compositions. Furthermore, the addition of PVPh is able to enhance the miscibility of the immiscible PVP/PEMA and eventually transforms it into a miscible blend, especially when the ratio between PVP/PEMA is 3:1, probably because of favorable physical interaction. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1205–1213, 2006     

Blends of plasticized poly(vinyl chloride) and waste flexible poly(vinyl chloride) with waste nitrile rubber powder

Blends of poly(vinyl chloride) (PVC) with varying contents of plasticizer and finely ground powder of waste nitrile rubber rollers were prepared over a wide range of rubber contents through high‐temperature blending. The effects of rubber and plasticizer (dioctyl phthalate) content on the tensile strength, percentage elongation, impact properties, hardness, abrasion resistance, flexural crack resistance, limiting oxygen index (LOI), electrical properties, and breakdown voltage were studied. The percentage elongation, flexural crack resistance, and impact strength of blends increased considerably over those of PVC. The waste rubber had a plasticizing effect. Blends of waste plasticized PVC and waste nitrile rubber showed promising properties. The electrical properties and LOI decreased with increasing rubber and plasticizer content. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1552–1558, 2004     

Miscibility and crystallization of biodegradable poly(butylene succinate-co-butylene adipate)/poly(vinyl phenol) blends

Miscibility, crystallization kinetics, crystal structure, and microstructure of biodegradable poly(butylene succinate-co-butylene adipate) (PBSA)/poly(vinyl phenol) (PVPh) blends were studied by differential scanning calorimetry, optical microscopy, wide angle X-ray diffraction, and small angle X-ray scattering in detail in this work. PBSA and PVPh are miscible as evidenced by the single composition dependent glass transition temperature and the negative polymer-polymer interaction parameter. Isothermal crystallization kinetics of PBSA/PVPh blends was investigated and analyzed by the Avrami equation. The overall crystallization rates of PBSA decrease with increasing crystallization temperature and the PVPh content in the PBSA/PVPh blends; however, the crystallization mechanism of PBSA does not change in the blends. Furthermore, blending with PVPh does not modify the crystal structure of PBSA. The microstructural parameters, including the long period, thickness of crystalline phase and thickness of amorphous phase, all become larger with increasing the PVPh content, indicating that PVPh mainly resides in the interlamellar region of PBSA spherulites in the blends.     

Contact angle behaviour of poly(vinyl chloride)/ epoxidized natural rubber miscible blends

—Contact angle studies of miscible poly(vinyl chloride)/epoxidized natural rubber (PVC/ ENR) blends were carried out in air using water and methylene iodide. The solid surface free energy was calculated from harmonic mean equations. Blending of PVC and ENR decreased their contact angle or increased their solid surface free energy due to the improved chain mobility, and the accumulation of excess polar sites at the surface through conformational alterations resulting from the specific interaction of PVC and ENR. The work of adhesion, interfacial free energy, spreading coefficient, and Girifalco-Good's interaction parameter changed markedly with the blend composition. In blends, PVC and ENR improved hydrophilicity, and wettability with polar and non-polar liquids. The presence of a plasticizer in PVC, in general, further improved the wettability and hydrophilicity in blends.     

Miscibility and transesterification in ternary blends of poly(ethylene naphthalate)/poly(pentamethylene terephthalate)/poly(ether imide)

Miscibility and morphology of poly(ethylene 2,6‐naphthalate)/poly(pentamethylene terephthalate)/poly(ether imide) (PEN/PPT/PEI) blends were studied by differential scanning calorimetry (DSC), optical microscopy (OM), proton nuclear magnetic resonance imaging (¹H‐NMR), and wide‐angle X‐ray diffraction (WAXD). OM and DSC results from ternary blends revealed the immiscibility of PEN/PPT/PEI blends, but ternary blends of all compositions were phase‐homogeneous following heat treatment at 300°C for over 60 min. Annealing samples at 300°C yielded an amorphous blend with a clear and single T_g at the final state. Experimental data from ¹H‐NMR revealed that PEN/PPT copolymers (ENPT) were formed by the so‐called transesterification. The effect of transesterification on glass transition and crystallization was discussed in detail. The sequence structures of the copolyester were identified by triad analysis, which showed that the mean sequence lengths became shorter and the randomness increased with heating time. The results reveal that a random copolymer improved the miscibility of the ternary blends, in which, the length of the homo segments in the polymer chain decreased and the crystal formation was disturbed because of the irregularity of the structure, as the exchange reaction proceeded. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3840–3849, 2006     

Miscibility and crystallization of poly(ethylene succinate)/poly(vinyl phenol) blends

Miscibility of biodegradable poly(ethylene succinate) (PES)/poly(vinyl phenol) (PVPh) blends has been studied by differential scanning calorimetry (DSC) in this work. PES is found to be miscible with PVPh as shown by the existence of single composition dependent glass transition temperature over the entire composition range. Spherulitic morphology and the growth rates of neat and blended PES were investigated by optical microscopy (OM). Both neat and blended PES show a maximum growth rate value in the crystallization temperature range of 45-65 °C, with the growth rate of neat PES being higher than that of blended PES at the same crystallization temperature. The overall crystallization kinetics of neat and blended PES was also studied by DSC and analyzed by the Avrami equation at 60 and 65 °C. The crystallization rate decreases with increasing the temperature for both neat and blended PES. The crystallization rate of blended PES is lower than that of neat PES at the same crystallization temperature. However, the Avrami exponent n is almost the same despite the blend composition and crystallization temperature, indicating that the addition of PVPh does not change the crystallization mechanism of PES but only lowers the crystallization rate.