Microwave dielectric relaxation and molecular dynamics in binary mixtures of poly(propylene glycol) 2000 and poly(ethylene glycol)s of varying molecular weight in dilute solution

Molecular dynamics of binary mixtures of poly(propylene glycol) (PPG) and poly(ethylene glycol)s (PEGs) of varying molecular weight due to molecular interactions, chain coiling and elongation in dilute solution under various conditions, ie varying number of monomer units of PEG, method of mixing of polymers and solvent environment, has been explored using microwave dielectric relaxation times. The average relaxation time τ_o, relaxation time corresponding to segmental motion τ₁ and group rotations τ₂, of a series of binary mixtures of poly(propylene glycol) 2000 and poly(ethylene glycol) of varying molecular weight (ie PPG 2000 + PEG 200, PPG 2000 + PEG 300, PPG 2000 + PEG 400, and PPG 2000 + PEG 600 mixed by equal volume in the pure liquid states, and PPG 2000 + PEG 1500, PPG 2000 + PEG 4000 and PPG 2000 + PEG 6000 mixed equal weights in solvent) have been determined in dilute solution in benzene and carbon tetrachloride at 10.10 GHz and 35 °C. A comparison of the results of these binary systems of highly associating molecules shows that the molecular dynamics corresponding to rotation of a molecule as a whole and segmental motion in dilute solutions are governed by the solvent density when the solutes are mixed in their pure liquid state. Furthermore, the molecular motion is independent of solvent environment when the polymers are added separately in the solvent for the preparation of binary mixtures. It has also been observed that there is a systematic elongation of the dynamic network of the species formed during mixing of pure liquid polymers in lighter environment of solvent with increasing PEG monomer units, while the elongation behaviour of the same species in the heavier environment of carbon tetrachloride solvent is in contrast to the elongation behaviour of the polymeric species formed in pure PEG. The role of rotating methyl side‐groups in the PPG molecular chain has been discussed in term of the breaking and reforming of hydrogen bonds in complex polymeric species for the segmental motion. In all these mixtures, the relaxation time corresponding to group rotations is independent of the solvent environment and constituents of the binary mixtures. The effect of chain flexibility and coiling in these binary mixtures is discussed by comparing the relaxation times of the mixtures with their individual relaxation times in dilute solutions measured earlier in this laboratory. © 2001 Society of Chemical Industry     

通过状态方程预测无定形和可结晶共混聚合物的压力-体积-温度和超摩尔体积（英文）

In this work the statistical mechanical equation of state was developed for volumetric properties of crystal ine and amorphous polymer blends. The Ihm–Song–Mason equations of state (ISMEOS) based on temperature and density at melting point (Tm andρm) as scaling constants were developed for crystalline polymers such as poly(propylene glycol)+poly(ethylene glycol)-200 (PPG+PEG-200), poly(ethylene glycol) methyl ether-300 (PEGME-350)+PEG-200 and PEGME-350+PEG-600. Furthermore, for amorphous polymer blends con-taining poly(2,6-dimethyl-1,4-phenylene oxide) (PPO)+polystyrene (PS) and PS+poly(vinylmethylether) (PVME), the density and surface tension at glass transition (ρg andγg) were used for estimation of second Virial coefficient. The calculation of second Virial coefficients (B2), effective van der Waals co-volume (b) and correction factor (α) was required for judgment about applicability of this model. The obtained results by ISMEOS for crys-talline and amorphous polymer blends were in good agreement with the experimental data with absolute aver-age deviations of 0.84%and 1.04%, respectively.     

End-group effect on chain conformation of poly(propylene glycol) and poly(ethylene glycol)

A comparison is made of the chain conformational distribution of hydroxy-terminated poly(propylene glycol) (PPG) and poly(ethylene glycol) (PEG) with their methoxy-terminated derivatives. The significant end-group dependence on the glass transition temperature in PPG was observed by differential scanning calorimetry. Raman active skeletal vibrations in the low-frequency region indicated a significant difference in chain conformation distribution between methoxy- and hydroxy-terminated PPGs, yet almost no difference between MPEG and HPEG. The increased chain stiffness in HPPG in comparison to MPPG has been attributed to the hydrogen-bonding interaction associated with the hydroxy end group in HPPG. Furthermore, the structural differences observed between PPG and PEG have been attributed to the differences in the interaction of the hydroxy end group to the ether oxygen in the two polymers. The interaction between the hydroxy end group and ether oxygen differs because the —CH₃ side group is present for one and not for the other. These structural differences are reflected in the glass transitions temperatures measured. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 197–202, 1997     

Miscibility of polystyrene with poly(ethylene oxide) and poly(ethylene glycol)

The intrinsic viscosity of polystyrene–poly(ethylene oxide) (PS–PEO) and PS–poly(ethylene glycol) (PEG) blends have been measured in benzene as a function of blend composition for various molecular weights of PEO and PEG at 303.15 K. The compatibility of polymer pairs in solution were determined on the basis of the interaction parameter term, Δb, and the difference between the experimental and theoretical weight-average intrinsic viscosities of the two polymers, Δ[η]. The theoretical weight-average intrinsic viscosities were calculated by interpolation of the individual intrinsic viscosities of the blend components. The compatibility data based on [η] determined by a single specific viscosity measurement, as a quick method for the determination of the intrinsic viscosity, were compared with that obtained from [η] determined via the Huggins equation. The effect of molecular weights of the blend components and the polymer structure on the extent of compatibility was studied. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 1471–1482, 1998     

Polymer electrolytes based on poly(ethylene glycol) and cyanoresin

Polymer electrolytes based on a mixed polymer matrix consisting of poly(ethylene glycol) (PEG) and cyanoresins with lithium salt and plasticizer were prepared with an in situ blending process to improve both the mechanical properties and the ionic conductivity (σ). The PEG/lithium perchlorate (LiClO₄) complexes, including blends of cyanoethyl pullulan (CRS) and cyanoethyl poly(vinyl alcohol) (CRV), exhibited higher σ's than a simple PEG/LiClO₄ complex when the blend compositions of CRS/CRV were 5 : 5 or 3 : 7 or than CRV alone. When the CRS/CRV blend was compared with a copolymer of cyanoethyl pullulan and cyanoethyl poly(vinyl alcohol) (CRM) in the same molar ratio, the σ values of the polymer electrolytes containing the CRM copolymer series were slightly higher than those of the CRS/CRV blends containing PEG/LiClO₄ complexes. Moreover, the addition of cyanoresin to PEG/LiClO₄/(ethylene carbonate–propylene carbonate) polymer electrolytes provided better thermal stability and dynamic mechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2402–2408, 2007     

Plasticization of semicrystalline poly(l-lactide) with poly(propylene glycol)

Plasticization of semicrystalline poly(l-lactide) (PLA) with a new plasticizer - poly(propylene glycol) (PPG) is described. PLA was plasticized with PPG with nominal M_w of 425 g/mol (PPG4) and 1000 g/mol (PPG1) and crystallized. The plasticization decreased T_g, which was reflected in a lower yield stress and improved elongation at break. The crystallization in the blends was accompanied by a phase separation facilitated by an increase of plasticizer concentration in the amorphous phase and by annealing of blends at crystallization temperature. The ultimate properties of the blends with high plasticizer contents correlated with the acceleration of spherulite growth rate that reflected accumulation of plasticizer in front of growing spherulites causing weakness of interspherulitic boundaries. In PLA/PPG1 blends the phase separation was the most intense leading to the formation of PPG1 droplets, which facilitated plastic deformation of the blends that enabled to achieve the elongation at break of about 90-100% for 10 and 12.5 wt% PPG1 content in spite of relatively high T_g of PLA rich phase of the respective blends, 46.1-47.6 °C. Poly(ethylene glycol) (PEG), long known as a plasticizer for PLA, with nominal M_w of 600 g/mol, was also used to plasticize PLA for comparison.     

Effect of poly(ethylene glycol) on the solid‐state polymerization of poly(ethylene terephthalate)

Poly(ethylene glycol) (PEG) and end‐capped poly(ethylene glycol) (poly(ethylene glycol) dimethyl ether (PEGDME)) of number average molecular weight 1000 g mol^?1 was melt blended with poly(ethylene terephthalate) (PET) oligomer. NMR, DSC and WAXS techniques characterized the structure and morphology of the blends. Both these samples show reduction in T_g and similar crystallization behavior. Solid‐state polymerization (SSP) was performed on these blend samples using Sb₂O₃ as catalyst under reduced pressure at temperatures below the melting point of the samples. Inherent viscosity data indicate that for the blend sample with PEG there is enhancement of SSP rate, while for the sample with PEGDME the SSP rate is suppressed. NMR data showed that PEG is incorporated into the PET chain, while PEGDME does not react with PET. Copyright © 2005 Society of Chemical Industry     

Surface modification of polypropylene. I. Surface enrichment of poly(ethylene glycol) on polypropylene/poly(ethylene glycol) blends

The enrichment of poly(ethylene glycol) (PEG) on the surface of poly(ethylene glycol)/polypropylene (PEG/PP) blends was investigated by using attenuated total reflection infrared spectroscopy (ATR‐FTIR), contact angle measurement (CDA), and scanning electron microscopy (SEM). The preferred aggregation of the PEG component on the film surface of PP/PEG blends was affected mainly by the content, the molecular weight, and the segregated domains of PEG. Lower content and dies with higher surface energy favored the surface enrichment of PEG. The PEG with higher molecular weights was distributed in PP with larger phase domains, which resulted in a lower tendency toward preferred aggregation and surface enrichment. J. VINYL ADDIT. TECHNOL, 2008. © 2008 Society of Plastics Engineers     

Antistatic performance and morphological observation of ternary blends of poly(ethylene terephthalate), poly(ether esteramide), and ionomers

Blends of poly(ethylene terephthalate) (PET) and poly (ether esteramide) (PEEA), which is known as an ion conductive polymer, were prepared by melt mixing using a twin screw extruder. Antistatic performance of the molded plaques and the effects of adding ionomers such as lithium neutralized poly(ethylene‐co‐methacrylic acid) copolymer(E/MAA‐Li), magnesium neutralized poly(ethylene‐co‐methacrylic acid) copolymer(E/MAA‐Mg), and zinc neutralized poly(ethylene‐co‐methacrylic acid) copolymer (E/MAA‐Zn) were investigated. Antistatic effect of adding poly(ethylene‐co‐methacrylic acid) copolymer(E/MAA) and polystyrene, and poly(ethylene naphthalate) (PEN) into PET/PEEA blends were also investigated. Here we confirmed that lithium ionomer worked the most effectively in those blend systems. We also confirmed that E/MAA worked to enhance the antistatic performance of PET/PEEA blends. Morphological study of these ternary blends system was conducted by TEM. Specific interaction between PEEA and E/MAA‐Li, and E/MAA were observed. Those ionomers and copolymer domains were encapsulated by PEEA, which could increase the surface area of PEEA in PET matrix. This encapsulation effect explains the unexpected synergy for the static dissipation performance on addition of ionomers and E/MAA to PET/PEEA blends. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers     

Properties of Poly(vinyl chloride)/poly(ethylene oxide)/polyaniline Conductive Films: The Effect of Poly(ethylene glycol) Diglycidyl Ether

The effect of polyaniline and poly(ethylene glycol) diglycidyl ether on tensile properties, morphology, thermal degradation, and electrical conductivity of poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films was studied. The poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films were prepared using a solution casting technique at room temperature until a homogeneous solution was produced. Poly(vinyl chloride)/poly(ethylene oxide)/polyaniline/poly(ethylene glycol) diglycidyl ether conductive films exhibit higher electrical properties, tensile strength, modulus of elasticity but lower final decomposition temperature than poly(vinyl chloride)/poly(ethylene oxide)/polyaniline conductive films. Scanning electron microscopy morphology showed that the polyaniline more widely dispersed in the poly(vinyl chloride)/poly(ethylene oxide) blends with the addition of poly(ethylene glycol) diglycidyl ether as surface modifier.     

Mesoporous carbon membranes from polyimide blended with poly(ethylene glycol)

The control of the mesoporous structure in a carbon membrane from a poly(ethylene glycol)/polyimide‐blended polymer was investigated. The size of the pores tends to become large with increase of the content of poly(ethylene glycol) against polyimide, that is, the mesoporous structure could be controlled by the composition of the blended polymers. On the other hand, the average molecular weight of poly(ethylene glycol) has little effect from the viewpoint of the control of the pore structure. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 836–841, 2001     

Polymer gel electrolytes prepared by thermal curing of poly(vinylidene fluoride)-hexafluoropropene/poly(ethylene glycol)/propylene carbonate/lithium perchlorate blends

In an effort to prepare a poly(vinylidene fluoride)-hexafluoropropene (PVdF-HFP) based polymer gel film electrolyte with higher mechanical strength and little volatility, a two component urethane system employing blocked multiisocyanate as a potential thermal crosslinking agent, and low molar mass poly(ethylene glycol) (PEG) as a hydroxy-functional coreactant was blended with the PVdF-HFP gel system, and the cure of the blends was examined as a function of temperature, molar mass of PEG, and PEG/blocked isocyanate ratio. The network forming reaction could not proceed below 100 °C, but it slowly took place above 120 °C by thermal deblocking of blocked multiisocyanate, followed by the reaction of regenerated free multiisocyanate with PEG in the absence and presence of PVdF-HFP, plasticizer (propylene carbonate, PC) and lithium perchlorate. The adduct of polymeric methylene diphenyl diisocyante (PMDI) with acetone oxime was used as a potential thermal crosslinking agent for this study. Network polymer gels having no PVdF-HFP were also prepared for comparison. The cured (PVdF-HFP/PEG/blocked PMDI/PC/LiClO₄) polymer gel networks were mechanically and dimensionally stable, and their thermal characteristics and electrochemical properties were investigated using FT-IR spectroscopy, differential scanning calorimetry, electrochemical impedance spectroscopy and linear sweep voltammetry.     

Miscibility studies on poly(ethylene glycol)/dextran blends in aqueous solutions by dilute solution viscometry

Miscibility of poly(ethylene glycol) (PEG) with dextran (Dx) was investigated by dilute solution viscometry. Dilute solution viscosity measurements were made on ternary systems, polymer (1)/polymer (2)/solvent (H₂O), for four different average molecular weights of PEG and Dx. The intrinsic viscosity and viscometric interaction parameters were experimentally measured for the binary (solvent/polymer) as well as for the ternary systems by classical Huggins equation. Degree of miscibility of these polymer systems was estimated on the basis of the four following criteria: (1) the sign of the Δk_AB, (2) the sign of α, (3) the sign of ΔB, and (4) the sign of the μ. Based on the sign convention involved in these criteria, immiscibility was observed in most systems. The miscibility of all these systems in accordance with the interactions between the unlike polymer chains rather the polymer–solvent interactions were investigated depending on molecular weight of polymer sample. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 453–460, 2004     

Structure–property relationships of poly(urethane‐urea)s with ultralow monol content poly(propylene glycol) soft segments. III. influence of mixed soft segments of ultralow monol poly(propylene glycol), poly(tetramethylene ether glycol), and tri(propylene glycol)

Recent advances in the catalyst technology associated with the production of poly(propylene glycol) (PPG) have allowed for the fabrication of ultralow monol content PPG macrodiols (Acclaim? polyols), which are highly bifunctional and can be produced in substantially higher molecular weights and with narrower molecular weight distributions than previously possible. These factors have enabled the preparation of higher value elastomers and may allow for the first manufacture of economically attractive PPG‐based poly(urethane‐urea) (PUU) fibers. In the past, many performance polyurethane and PUU elastomers used poly(tetramethylene ether glycol) (PTMEG) for the soft segments either alone or in combination with other macrodiols. The work presented here details the investigation of the morphological features of PUU systems with mixed soft segments of PPG, PTMEG, and a low molecular analog of PPG, tri(propylene glycol) (TPG) in an effort to ascertain the influence of structural features on the mechanical and thermal properties of the elastomers. Also of interest was whether the incorporation of PPG and TPG would either prohibit or greatly hinder the formation of strain‐induced PTMEG crystallites. It was found that, even when only 60 wt % of the soft segments consisted of PTMEG, those soft segments were still able to undergo recognizable strain‐induced crystallization as detected by wide‐angle X‐ray scattering. It was also seen that, as the ratio of PPG to PTMEG was varied, there were systematic changes in the soft segment glass transition and cold crystallization characteristics. Inclusion of PPG and TPG resulted in PTMEG's diminished ability to undergo cold and strain‐induced crystallization, as seen with differential scanning calorimetry and wide‐angle X‐ray scattering. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3520–3529, 2003     

Effect of various types of interaction on the stability of some ternary interpolymer complexes involving poly(ethylene imine), poly(acrylic acid) and poly(ethylene glycol)

The effect of various types of interaction on the stability of multi‐component interpolymer complexes was studied for some three‐component interpolymer complexes involving poly(ethylene imine), poly(acrylic acid) and poly(ethylene glycol). The degree of linkage (θ), stability constant (K) and related thermodynamic parameters (e.g. ΔH⁰ and ΔS⁰) of these complexes were determined at several temperatures and compared for various complexation systems. The comparative study indicated considerable difference in the values of these parameters, which is explained in terms of various modes of interaction between the components. Copyright © 2010 Society of Chemical Industry     

Synthesis of nylon 6-g-poly(ethylene glycol) copolymer and its compatibilizing effect in nylon 6/poly(ethylene glycol) blends

Summary A graft copolymer of poly(ethylene glycol) onto nylon 6 was prepared by two-step reactions; poly(ethylene glycol) (PEG) was chlorinated with thionyl chloride in carbon tetrachloride and the chlorinated PEG was then grafted onto nylon 6 by reacting each other with triethylamine and tin chloride in o-chlorophenol. Blends were also prepared from the graft copolymer with nylon 6 or PEG. The thermal properties and crystalline structure of the graft copolymer and the blends were studied using differential scanning calorimeter and X-ray diffractometer. It was found that the grafting of PEG onto nylon 6 changed the crystal structure of nylon 6. It was observed that compatibilization of the nylon 6/PEG blend of 50/50 composition by weight was achieved in the presence of the graft copolymer.     

异端基遥爪聚乙二醇的合成

采用3种新式引发剂,即2-(苄氧基）乙醇钾、2-(四氢-2H-吡喃-2-氧基)乙醇钾、单丙烯基乙二醇钾引发环氧乙烷阴离子开环聚合,反应条件为25 ℃、48 h、醇与萘钾摩尔比例1∶1,得到3种异端基遥爪聚乙二醇。以2-(苄氧基）乙醇钾引发聚合所得产物为起始物,经一系列反应,得到两种两端均为活性基团的异端基遥爪聚乙二醇,这种方法具有普适性。通过1HNMR及GPC手段,表征了产物的结构、分子量及分子量分布。结果表明可以得到高产率、分子量可控且分布窄的异端基遥爪聚乙二醇。     

聚丁二酸丁二醇酯/聚乙二醇硬脂酸酯共混物非等温结晶行为

以聚丁二酸丁二醇酯（PBS）和聚乙二醇硬脂酸酯（PEOST）为原料,采用溶液共混法制备了PEOST质量分数分别为10%（POS-10）和30%（POS-30）的两种合金材料。通过差示扫描量热法（DSC）研究了合金材料的非等温结晶行为,用莫志深（Mo）法分析了PBS的非等温结晶动力学,采用Kissinger法和Friedman法计算PBS的结晶活化能,并用红外（FTIR）和偏光显微镜（POM）进行表征。研究结果表明：PBS先结晶形成结晶微区不利于PEOST结晶,而较高含量的PEOST有利于PBS的结晶。受PBS先结晶的影响,POS-10降温DSC曲线没有出现PEOST的结晶峰,而POS-30在低的降温速率情况下出现了PEOST双结晶峰;升温DSC曲线中两试样均出现了PEOST的熔融峰。在相同的冷却速率下,POS-30的PEOST熔融温度（T_m）和熔融焓（△H_m）大于POS-10;POS-30的PBS结晶峰温度（T_p）、结晶焓（△H_c）大于POS-10,而结晶半峰宽（D）值更小;但两者的T_m和△H_m相当。随冷却速率的增加,PBS的D值增大,而PEOST的D值却降低;冷却速率的增加对PBS的T_m值影响不大,但使PEOST的T_m略有减小。Mo法适合用于共混物中PBS的非等温结晶动力学分析。POS-30的PBS绝对值结晶活化能要大于POS-10。POS-30在红外光谱谱图中出现了PEOST结晶的红外响应峰（1109cm^-1和841cm^-1）而POS-10没有。     

Unsaturated polyester based on poly(ethylene glycol)

Unsaturated polyesters were prepared by one-stage melt condensation of maleic anhydride, phthalic anhydride, propylene glycol, and poly(ethylene glycol)s with different molecular weight, and the properties of their castings from styrenated resins were investigated. Tensile and flexural properties decrease with the increase of molecular weight of poly(ethylene glycol), but impact strength, elongation, and water absorption have an inverse effect. This study improves the understanding of the effect of chain length of poly(ethylene glycol) in unsaturated polyester on the properties of its castings.     

Structural characterization and luminescent properties of poly(p-phenylene vinylene) and poly(ethylene glycol) blends

The luminescent properties of poly(p-phenylenevinylene) (PPV) blending with poly (ethylene glycol) (PEG) were investigated in terms of their structural formation during sample preparation. The blended systems were prepared from an aqueous solution of water-soluble poly (xylylene tetrahydrothiophenium chloride) (PPV precursor) mixed with PEG, followed by heat treatment to remove the tetrahydrothiophene groups from the PPV precursor. Structural analysis showed that PEG could react with PPV precursor to form C-O-C linkage and carbonyl groups in PPV chains, interrupting their conjugated length as suggested by their Infrared, Raman and UV/vis spectroscopes. Wide angle X-ray scattering (WARS) of blended systems also showed that PPV in blends had less packing. As to luminescent properties, the UV/vis and photoluminescent (PL) spectra show that the energy gap needed to produce the excitons increased along with the increase of PL intensity when PPV was blended with PEG. Similar results were also found for the EL properties of ITO/polyblends/Al devices. The EL light emission from blends was blue-shifted (compared to PPV) with a rather low threshold electric field strength. The EL performance of polyblends was better than that of pure PPV. Among them, the PPV-50PEG showed the highest EL intensity. The improved EL efficiency was attributed to the dilution effect, interrupted conjugated length, and lower packing of PPV chains.