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1.
Chlorinated poly(vinyl chloride) (CPVC) was solution blended with poly(caprolactone) (PCL), poly(hexamethylene sebacate) (PHMS), poly(α-methyl-α-n-propyl-β-propiolactone) (PMPPL), poly(valerolactone) (PVL), poly(ethylene adipate), poly(ethylene succinate) and poly(β-propiolactone). From calorimetric glass transition temperature (Tg) measurements, it is concluded that CPVC is miscible with polyesters having a CH2/COO ratio larger than three (PCL, PHMS, PMPPL and PVL). The Gordon-Taylor k parameter was also calculated and found equal to 1.0 and 0.56 for PCL/CPVC and PHMS/CPVC blends, respectively. From these values, it is concluded that CPVC gives a stronger interaction with polyesters than poly(vinyl chloride) due to its larger chlorine content. 相似文献
2.
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 (Tg) and the measured Tg fit well with the predicted Tg value by the Fox equation and Gordon‐Taylor equation. In addition to that, a single composition‐dependent cold crystallization temperature (Tcc) value can be observed and it decreases nearly linearly with the low Tg 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 (Tmc) of the blends decreased with an increase of the minor component and the 50/50 sample showed the lowest Tmc value, which is also related to its miscible nature in the melting state. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
3.
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 Tg 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 相似文献
4.
Robert E. Prud'homme 《Polymer Engineering and Science》1982,22(2):90-95
Poly(caprolactone) (PCL)/poly(vinyl chloride) (PVC) blends are known to be miscible in the solid state. Recents measurements however indicate that a large number of polyesters are also miscible with PVC if the ratio CH2/C?O of the polyester is between 4 and 10. At low CH2/C?O ratios, polyesters are too rigid to interact specifically with PVC. At high CH2/C?O ratios, the number of interacting groups becomes too small to give miscibility. Similarly, a large number of chlorinated polymers are shown to be miscible with PCL if their chlorine content is high enough. Surprisingly, polyesters are not in general miscible with chlorinated polymers if the mixture does not contain either PCL or PVC. The results presented in this paper suggest that a dipole-dipole interaction, between the carbonyl groups and the C-Cl groups, is responsible for the miscibility phenomena observed in polyester/chlorinated polymer blends. 相似文献
5.
Miscibility, phase diagrams and morphology of poly(ε‐caprolactone) (PCL)/poly(benzyl methacrylate) (PBzMA)/poly(styrene‐co‐acrylonitrile) (SAN) ternary blends were investigated by differential scanning calorimetry (DSC), optical microscopy (OM), and scanning electron microscopy (SEM). The miscibility window of PCL/PBzMA/SAN ternary blends is influenced by the acrylonitrile (AN) content in the SAN copolymers. At ambient temperature, the ternary polymer blend is completely miscible within a closed‐loop miscibility window. DSC showed only one glass transition temperature (Tg) for PCL/PBzMA/SAN‐17 and PCL/PBzMA/SAN‐25 ternary blends; furthermore, OM and SEM results showed that PCL/PBzMA/SAN‐17 and PCL/PBzMA/SAN‐25 were homogeneous for any composition of the ternary phase diagram. Hence, it demonstrated that miscibility exists for PCL/PBzMA/SAN‐17 and PCL/PBzMA/SAN‐25 ternary blends, but that the ternary system becomes phase‐separated outside these AN contents. Copyright © 2003 Society of Chemical Industry 相似文献
6.
Dynamic viscoelastic properties for miscible blends of poly(?‐caprolactone) (PCL) and poly(styrene‐co‐acrylonitrile) (SAN) were measured. It was found that the time–temperature superposition principle is applicable over the entire temperature range studied for the blends. The temperature dependency of the shift factors aT can be expressed by the Williams–Landel–Ferry equation: log aT = ?8.86(T ? Ts)/(101.6 + T ? Ts). The compositional dependency of Ts represents the Gordon–Taylor equation. The zero‐shear viscosities are found to increase concavely upward with an increase in weight fraction of SAN at constant temperature, but concavely downward at constant free volume fraction. It is concluded that the relaxation behavior of the PCL/SAN blends is similar to that of a blend consisting of homologous polymers. It is emphasized that the viscoelastic functions of the miscible blends should be compared in the iso‐free volume state. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2037–2041, 2001 相似文献
7.
The miscibility and interactions of binary blends of poly(4-hydroxystyrene) brominated (P4HSBR) with poly(?-caprolactone) (PCL), poly(vinyl acetate) (PVA) and poly(vinyl methylether) (PVME) are investigated by means of differential scanning calorimetry (DSC). Glass transition temperatures, Tgs, are used to assess the miscibility of these systems. All of them were found to be miscible over the whole composition range. Tgs of the blends are lower than Fox predictions, in contrast to the results previously obtained for systems involving poly(4-hydroxystyrene) (P4HS). The melting of PCL in the blends was studied. From the melting temperature depression of PCL in the blends the polymer-polymer interaction parameter was obtained and compared with the ones obtained for P4HS/PCL and poly(4-hydroxystyrene-co-methoxystyrene) (P4HSM)/PCL systems. The best interactions are achieved in P4HS/PCL and the bromination or methoxylation of the P4HS worsen the interactions with the PCL. The presence of a cusp in the Tg-composition curve was analysed in terms of the Kovacs' theory in systems with P4HS and P4HSBR. 相似文献
8.
Lloyd M. Robeson 《乙烯基与添加剂工艺杂志》1990,12(2):89-94
Polymer blends have received particular interest in the past several decades in both industrial and academic research. An initial survey of miscible polymer pairs (1) (1968) revealed 12 combinations. A later survey (2) (1979) noted approximately 180 miscible pairs. Today possibly over 500 miscible combinations have been noted in the open and patent literature (3). However, the vast majority of possible polymer blend combinations are not miscible (thus phase separated). A significant number of diverse polymer structures have been shown to exhibit miscibility with PVC. Several of these blends have been studied in detail and have shown specific interactions primarily involving the α-hydrogen and PVC (considered the proton donor in proton donor-proton acceptor hydrogen bonding type interactions). The blend of poly(?-caprolactone) with PVC illustrates this interaction and has been reported in many published papers. While polymer miscibility in PVC blends offers significant academic interest, industrial utility is also of considerable importance. The addition of low Tg, miscible polymers to PVC offers permanent plasticization. The addition of high Tg, miscible polymers to PVC yields the desired heat distortion temperature enhancement of rigid PVC. A specific example of permanent plasticization involves nitrile rubber blends which have been commercial since the early 1940's. This presentation will review the growing number of polymers noted to be miscible with PVC. The importance of specific interactions will be discussed. 相似文献
9.
Samy A. Madbouly 《应用聚合物科学杂志》2007,103(5):3307-3315
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 (Tc) using differential scanning calorimetric (DSC) and polarized optical microscope techniques. Only a single glass‐transition temperature, Tg, was determined for each mixture indicating that this binary blend is miscible over the entire range of composition. The composition dependence of the Tg 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 Tg 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 t0.5 increased monotonically with the crystallization temperature for all composition. At any crystallization temperature (Tc) the t0.5 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 相似文献
10.
Poly(styrene-co-acrylonitrile)(SAN) and poly(α-methyl styrene-co-acrylonitrile)(MSAN) are miscible with poly(2-hydroxyethyl methacrylate) (PHEMA) and with poly(2-hydroxypropyl methacrylate) (PHPMA). That SAN and MSAN are immiscible with poly(n-propyl methacrylate) and with poly(isopropyl methacrylate) but miscible with PHPMA indicates the enhancement of polymer miscibility due to hydroxyl groups. The miscibility of these blends is explained in terms of recent theories for copolymer/homopolymer blends. 相似文献
11.
The dielectric properties of miscible blends of poly(vinyl chloride) (PVC) and poly(α-methyl-α-n-propy-β-propiolae-tone) (PMPPL) have been investigated at different temperatures above and below Tg. The results were analyzed using the Cole-Cole representation and lead to the conclusion that this mixture does not exhibit micro-scale heterogeneities. Dielectric constant and dielectric loss master curves were constructed using the stress relaxation shift factors determined previously; the same shift factors could be used for the homopolymers and their blends. Similarities between the dielectric master curves and the stress relaxation master curves of PVC, PMPPL, and their blends, are also discussed. 相似文献
12.
Marvin H. Lehr 《Polymer Engineering and Science》1985,25(17):1056-1068
Blends of poly(vinyl chloride) with chlorinated poly(vinyl chloride) (PVC), and blends of different chlorinated poly(vinyl chlorides) (CPVC) provide an opportunity to examine systematically the effect that small changes in chemical structure have on polymer-polymer miscibility. Phase diagrams of PVC/CPVC blends have been determined for CPVC's containing 62 to 38 percent chlorine. The characteristics of binary blends of CPVC's of different chlorine contents have also been examined using differential calorimetry (DSC) and transmission electron microscopy. Their mutual solubility has been found to be very sensitive to their differences in mole percent CCl2 groups and degree of chlorination. In metastable binary blends of CPVC's possessing single glass transition temperatures (Tg) the rate of phase separation, as followed by DSC, was found to be relatively slow at temperatures 45 to 65° above the Tg of the blend. 相似文献
13.
Two series of copolymers have been prepared from α-methylstyrene and α-methylstyrene units modified by the incorporation of the hydrogen-bond donor units, methyl carbinol and trifluoromethyl carbinol, designated PαMS ( I ) and PαMS ( II ), respectively. It has been observed that if the concentration of the donor unit exceeds 4 mol %, one-phase blends can be prepared with a series of polymers containing hydrogen-bond acceptor sites such as poly(vinyl acetate), poly(vinyl pyrrolidone), poly(4-vinyl pyridine), and some poly(alkyl acrylate)s, none of which are miscible with the unmodified PαMS. All the one-phase blends formed are stable at temperatures above the glass transition temperature, Tg, of the blend, but eventually phase separate when the temperature is increased sufficiently. These lower critical cloud-point curves have been measured for a wide range of the blends and act as an indicator of the effectiveness of the hydrogen bonds in enhancing one-phase blend formation. The Tg's of the blends are in many cases higher than those calculated from the simple rule of mixtures and reflect the reduction in chain mobility in the blends caused by extensive hydrogen bonding. The results demonstrate the effect that specific interactions have in enhancing miscibility in binary polymer blends. © 1993 John Wiley & Sons, Inc. 相似文献
14.
Isotactic, atactic, and syndiotactic poly(methyl methacrylates) (i, a, and s PMMAs) were mixed with poly(vinylidene chloride‐co‐acrylonitrile) (Saran F) separately in tetrahydrofuran to make three polymer blend systems. Differential scanning calorimetry (DSC) was used mainly to study the miscibility of these blends. iPMMA and aPMMA were found to be miscible with Saran F based on the transparency and a single glass transition temperature (Tg) of the films. However, sPMMA was immiscible with Saran F because of the observation of two Tgs and opacity in most compositions of the blend. aPMMA is known to be miscible with sPMMA. Therefore aPMMA is both miscible with Saran F and sPMMA but Saran F and sPMMA are immiscible. Preliminary results of the effect of adding of aPMMA to immiscible sPMMA and Saran F mixtures were also reported. First, binary mixtures of atactic and syndiotactic PMMAs were also prepared and confirmed to be miscible. Elevation of Tg of the aPMMA/sPMMA blend above weight average was observed probably due to stereocomplexation occurred between aPMMA and sPMMA. Then ternary blends of atactic and syndiotactic PMMAs and Saran F in the weight ratios of about 3/1/4, 2/2/4, and 1/3/4 were also measured calorimetrically. A single Tg was observed for these three compositions different from two Tgs detected in the sPMMA/Saran F (50.0/50.0, i.e., 4/4) blend. Obviously, the composition of Saran was fixed in the ternary blends. When the other half of the blends was changing from pure sPMMA to sPMMA and aPMMA mixture, the blends became miscible because of the addition of aPMMA. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 1313–1321, 2000 相似文献
15.
Tsung-Tang Hsieh Carlos Tiu Kuo-Huang Hsieh George P. Simon 《Journal of Polymer Research》1999,6(4):211-218
Blends of a thermotropic liquid crystalline polymer [poly(p-oxybenzoate-co-p-phenylene isophthalate)] (HIQ45) and a polycarbonate (PC) are studied with regard to their miscibility and free volume behavior.
The glass transition temperatures (Tgs) of the blends are found to be uncharacteristically higher than those of the pure components, even increasing with the addition
of the low-Tg component, HIQ45. Based on the non-appearance of the Tg of HIQ45 in the tanδ spectra of the blends and the observed homogeneous morphology of the blend, mixtures of HIQ45 and PC
are concluded to be a miscible blend system. The free volume properties determined by positron annihilation lifetime spectroscopy
show that close packing does not occur in these miscible blends as indicated by positive deviations in size and number concentration
of free volume cavities from average values as a function of blend composition. The increase in free volume is attributed
to the loss of liquid crystalline alignment of HIQ45 and disturbed packing of PC molecules due to intimate miscibility between
different molecules. The free volume fraction index of the blend correlates well with measured blend density. 相似文献
16.
The miscibility and morphology of poly(caprolactone) (PCL) and poly (4-vinylphenol) (PVPh) blends were investigated by using differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy and 13C solid state nuclear magnetic resonance (NMR) spectroscopy. The DSC results indicate that PCL is miscible with PVPh. FTIR studies reveal that hydrogen bonding exists between the hydroxyl groups of PVPh and the carbonyl groups of PCL. 13C cross polarization (CP)/magic angle spinning (MAS)/dipolar decoupling (DD) spectra of the blends show a 1 ppm downfield shifting of 13C resonance of PVPh hydroxyl-substituted carbons and PCL carbonyl carbons with increasing PCL content. Both FTIR and NMR give evidence of inter-molecular hydrogen bonding within the blends. The proton spin-lattice relaxation in the laboratory frame, T1(H), and in the rotating frame, T1ρ(H), were studied as a function of the blend composition. The T1(H) results are in good agreement with thermal analysis; i.e. the blends are completely homogeneous on the scale of 50-80 nm. The T1ρ(H) results indicate that PCL in the blends has both crystalline and amorphous phases. The amorphous PCL phase is miscible with PVPh, but the PCL crystal domain size is probably larger than the spin-diffusion path length within the T1ρ(H) time-frame, i.e. larger than 2-4 nm. The mobility differences between the crystalline and amorphous phases of PCL are clearly visible from the T1ρ(H) data. 相似文献
17.
A study has been made of the isothermal crystallization kinetics of poly(ε‐caprolactone) (PCL) in partially miscible crosslinked polyester resin (PER)/PCL blends by using differential scanning calorimetry (DSC). For comparison, miscible blends of PCL with uncured polyester resin, i.e., oligoester resin (OER), were also investigated. The overall crystallization rate of PCL remarkably decreased with the addition of amorphous component, OER or PER. The kinetic rate constant Kn decreased sharply for both the OER/PCL blends and the crosslinked PER/PCL blends with decreasing PCL concentration. The mechanism of nucleation and geometry of the growing PCL crystals was not remarkably affected by the incorporation of OER, but changed considerably with the addition of PER. However, the overall crystallization rate of PCL in the crosslinked PER/PCL blends was much higher compared with the corresponding uncured OER/PCL blends, which is attributable to the phase‐separated structure and the reduced miscibility in the crosslinked blends. According to the nucleation and growth theories, the nucleation process was considered to be the rate controlling step in the crystallization. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 322–327, 1999 相似文献
18.
A ternary blend system comprising poly(cyclohexyl methacrylate) (PCHMA), poly(α‐methyl styrene) (PαMS) and poly(4‐methyl styrene) (P4MS) was investigated by thermal analysis, optical and scanning electron microscopy. Ternary phase behaviour was compared with the behaviour for the three constituent binary pairs. This study showed that the ternary blends of PCHMA/PαMS/P4MS in most compositions were miscible, with an apparent glass transition temperature (Tg) and distinct cloud‐point transitions, which were located at lower temperatures than their binary counterparts. However, in a closed‐loop range of compositions roughly near the centre of the triangular phase diagram, some ternary blends displayed phase separation with heterogeneity domains of about 1 µm. Therefore, it is properly concluded that ternary PCHMA/PαMS/P4M is partially miscible with a small closed‐loop immisciblity range, even though all the constituent binary pairs are fully miscible. Thermodynamic backgrounds leading to decreased miscibility and greater heterogeneity in a ternary polymer system in comparison with the binary counterparts are discussed. © 2003 Society of Chemical Industry 相似文献
19.
The miscibility behavior of poly(2-chloroethyl methacrylate) (PCEMA) with various polymethacrylates was investigated by differential scanning calorimetry. PCEMA is miscible with poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), and poly(tetrahydrofurfuryl methacrylate) (PTHFMA), but is immiscible with poly(n-propyl methacrylate), poly(isopropyl methacrylate), poly(n-butyl methacrylate), and poly(cyclohexyl methacrylate). PCEMA/PEMA blends showed lower critical solution temperature (LCST) behavior but PCEMA/PMMA and PCEMA/PTHFMA blends degraded before phase separation could be induced. The miscibility behavior of PCEMA is similar to that of a chlorinated polymer. 相似文献
20.
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 (σe) 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 相似文献