Compatibility of polyacrylates and polymethacrylates with poly(vinyl chloride): 1. Compatibility and temperature variation

Mixtures of a series of polymethacrylates and polyacrylates with PVC were prepared by solvent casting from methyl ethyl ketone. Some mixtures were also prepared by mechanical mixing and in situ polymerization (polymerization of vinyl chloride monomer in the presence of the other polymer). The mixtures were assessed for compatibility by dynamic mechanical measurements and optical clarity. It was found that all polymethacrylates from poly(methyl methacrylate) to poly(n-hexyl methacrylate) were compatible with PVC as were poly(n-propyl acrylate) and poly(n-butyl acrylate). Higher chain polyacrylates are incompatible. Poly(methyl acrylate) and poly(ethyl acrylate) appear incompatible with PVC when mixtures are prepared by solvent casting, but compatible when prepared by in situ polymerization, and mechanical mixtures show some sign of compatibility. It seems possible that in this case the solvent interferes with the compatibility. Mixtures of PVC with poly(n-hexyl methacrylate), poly(n-butyl acrylate) and poly(n-propyl acrylate) phase separate when heated in the region between 100°C and 160°C indicating the existence of a lower critical solution temperature.     

Compatibility in a blend of poly(2,3-dichloro-1-propyl acrylate) and poly(glycidyl methacrylate–co–ethyl acrylate)

The compatibility of mixtures of poly(2,3-dichloro-1-propyl acrylate) and poly(glycidyl methacrylate–co–ethyl acrylate) has been investigated by measurement of the following properties: density, light transmission, glass transition temperature, vapor absorption, and NMR relaxation times. To varying degrees, all results provided evidence supporting the contention that these mixtures are compatible.     

Study of dynamic mechanical properties of poly(vinyl chloride)–ethylene vinyl acetate copolymer and poly(vinyl chloride)–chlorinated ethylene vinyl acetate copolymer mixtures

The compatibility of the mixtures poly(vinyl chloride)—ethylene vinyl acetate copolymer and poly(vinyl chloride)—chlorinated ethylene vinyl acetate copolymer was studied by the method of dynamic mechanical testing. The character of G′ and G″ was confronted with the Takayanagi model. In all cases a limited compatibility of the components was observed.     

Miscibility limits in poly(vinylethylene) isotopic mixtures

Summary The interaction parameter for isotopic mixtures of poly(vinylethylene) was determined from small angle neutron scattering measurements to vary from 6.6×10^–4 to 5.7×10^–4 over a temperature range of from just above T_g to 71°C. The phase behavior of these blends differs significantly from the predictions of Flory-Huggins theory, indicating that, in addition to their non-ideality, polymer isotopes do not form simple mixtures. This phase behavior, however, was found to be congruent with the symmetrical model of mixtures.     

Structural Characteristics and Thermal Transformations of a Poly(dimethylphenylsiloxane)-Polyurethane (Glycol Diisocyanate Oligomer) Mixture Prepared by Reactive Processing in a Toluene Solution

Semi-interpenetrating networks are prepared by reactive processing of cross-linked poly(dimethylphenylsiloxane) (PDMPS) and linear polyurethane (PU). Their structure and thermal properties are investigated by wide-angle X-ray scattering (WAXS), small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and IR spectroscopy. The characteristic size of nanophase-separated regions is approximately equal to 10² nm. The fine structure of the polymer components in domains formed is retained on a nanometer scale. The WAXS curves of the mixtures are characterized by additive contributions for all the concentrations under investigation. This indicates that the microphase separation occurs on the molecular level. The glass transition temperatures of mixtures are virtually equal to that of linear polyurethane (− 65°C). The polymer mixtures are destructed in the temperature range 240–700° C. In this range, the DSC curves exhibit thermal effects characteristic of individual polymers.Original Russian Text Copyright © 2005 by Fizika i Khimiya Stekla, Shilov, Glebova, Gomza, Golubkov, Ugolkov.     

Estimation of the Combustion and Detonation Parameters for Hydrocarbon Gas Hydrates

Calculated combustion and detonation parameters for methane—oxygen (air)—H₂O and acetylene—oxygen (air)—H₂O mixtures are presented. The values of the critical detonation–initiation energy are estimated as applied to methane and acetylene hydrates.     

A contribution to the fractionation of polystyrene — poly-(alpha-methylstyrene) mixture using the methyl ethyl ketone — benzene/methanol system

Summary The fractionation of polystyrene, poly(alpha-methylstyrene) and physical mixture of these homopolymers in methyl ethyl ketone — benzene/methanol system was investigated. The solubility of poly(alpha-methylstyrene) increases with the decreasing of molecular weight and becomes similar to polystyrene at ¯M_w 29,000. Polystyrene and poly(alpha-methylstyrene) which precipitate simultaneously have different molecular weight and can be further separated by another method.     

Cyclic potential sweep electrolysis for formation of poly(2-vinylpyridine) coatings

A cyclic potential sweep (CPS) technique has been used to form coatings of poly(2-vinylpyridine) on mild steel substrates by electropolymerization of the monomer. This method can produce thick and uniform coatings of much higher quality than can be formed by other electrochemical methods such as galvanostatic electrolysis, constant cell-potential electrolysis and chronoamperometry. The range and rate of the potential sweep during the CPS are important for successful coating formation. Potential sweeps between –1.0 and –2.2 V vs SCE at rates from 10 to 50 mV s^–1 have been found to be most suitable for the formation of poly(2-vinylpyridine) coatings. The essential reason for the successful application of the CPS technique to the electropolymerization process is the compatibility of the nature of the CPS process and the mechanism of 2-vinylpyridine electropolymerization.     

Mechanical properties, morphology, and crystallization behavior of blends of poly(l-lactide) with poly(butylene succinate-co-l-lactate) and poly(butylene succinate)

The blends of poly(l-lactide) (PLLA) with poly(butylene succinate) (PBS) and poly(butylene succinate-co-l-lactate) (PBSL) containing the lactate unit of ca. 3 mol% were prepared by melt-mixing and subsequent injection molding, and their mechanical properties, morphology, and crystallization behavior have been compared. Dynamic viscoelasticity and SEM measurements of the blends revealed that the extent of the compatibility of PBSL and PBS with PLLA is almost the same, and that the PBSL and PBS components in the blends with a low content of PBSL or PBS (5-20 wt%) are homogenously dispersed as 0.1−0.4 μm particles. The tensile strength and modulus of the blends approximately followed the rule of mixtures over the whole composition range except that those of PLLA/PBS 99/1 blend were exceptionally higher than those of pure PLLA. All the blends showed considerably higher elongation at break than pure PLLA, PBSL, and PBS. Differential scanning calorimetric analysis of the blends revealed that the isothermal and non-isothermal crystallization of the PLLA component is promoted by the addition of a small amount of PBSL, while the addition of PBS was much less effective.     

Ionic conductivity of polyelectrolyte derivatives of poly(vinyl alcohol)-lithium ion complex films

Summary Ionic conductivity of various polymeric hybrid complexes made from the polyelectrolytes carboxymethylated poly(vinyl alcohol) (PVAC), poly(vinyl alcohol) acetalized with glyoxylic acid (PVAG) and poly(vinyl alcohol) acetalized with iodine N-methyl-4-pyridyladehyde (PVAP) were investigated. It was found that when the content of carboxyl group in PVAC reaches 5.3% and the content of carboxyl group in PVAG is more than 9.7%, the ion conductivity of polymeric hybrid complexes rises sharply. These polymer—Li⁺ complex hybrids gave the ionic conductivity of 10^–6 Scm^–1 at room temperature.     

Cellulose containing block copolymers

Summary The preparation steps leading to trimethylcellulose — (b-poly(oxytetramethylene)) — block copolymers of the star type are described. This includes the synthesis of fully substituted cellulose derivative blocks each with one reactive endgroup by partial cleavage of trimethylcellulose, the activation of those endgroups to initiate the living cationic polymerization of poly(oxytetramethylene) — blocks and coupling of the resulting twoblocks by poly(4 — vinylpyridine) to form starshaped block copolymers.Herrn Prof. Dr. G. Manecke zu seinem 65. Geburtstag gewidmet     

Surface segregation in blends containing poly(dimethylsiloxane)-polystyrene block copolymers

The surface composition of polystyrene blends containing poly(dimethylsiloxane)-polystyrene block copolymers have been analyzed using X-ray photoelectron spectroscopy (XPS), contact angle measurements, and time-of-flight secondary ion mass spectrometry (TOFSIMS). The three techniques showed the surface of the blend samples to be identical to pure poly(dimethylsiloxane) homopolymer, despite the fact that the systems each contained only a 2% bulk concentration of siloxane. The high surface sensitivity of TOFSIMS—which probes the samples to depths of a few angstroms—indicates an enrichment of-Si(CH₃)₃ groups at the surface. These are the terminal groups of the PDMS part of the block. Their enrichment at the surface of the samples is presumably due to their low surface energy, in addition to the tendency for end groups to be at the surface due to free volume considerations.Presented at the XXVIth Silicon Symposium, Indiana University-Purdue University at Indianapolis, March 26–27, 1993.     

Compatibility of nylon 6 with poly(vinyl alcohol), hydroxylated poly(vinyl acetate) and poly(vinyl acetate)

Summary The compatibility of nylon 6 with poly(vinyl acetate)(PVAc) and poly(vinyl alcohol)(PVA) was investigated in terms of the melting-temperature depression. In order to vary the compatibility systematically, a hydroxylated poly(vinyl actate)(m-PVAc) was prepared by hydrolyzing PVAc with KOH in CH₃OH. It was found that the compatibility with nylon 6 is better in the systematic order PVA> m-PVAc> PVAc.     

Preparation and characterization of polyamide 66/poly(hydroxyl ether of bisphenol A) blends without compatibilizer

The polyamide 66 (PA66)/poly(hydroxyl ether of bisphenol A) (PHE) blend was successfully prepared by twin‐screw extrusion without the addition of any compatibilizer. The PA66/PHE blends had a microphase‐separated structure that varied from a sea‐island structure to a cocontinuous structure, and the mechanical properties were higher than the anticipated values on the basis of the rule of mixtures, which showed a synergistic effect. Fourier transform infrared spectroscopy and dynamic mechanical analysis illustrated that there was hydrogen‐bonding interaction between the amide groups of the PA66 and the pendant hydroxyl groups of the PHE. This led to the some degree of compatibility and the improvement in the mechanical properties of the blends. The polarized optical microscopy observation showed that the PA66 spherulites of the blend became smaller and more imperfect compared to those of the pure PA66, and differential scanning calorimetry measurement also showed a decrease in the melting temperatures of PA66 of the blend. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40437.     

Evidence for the amphiphilic structure of partially hydrogenolyzed poly(β-malic acid benzyl ester)

Summary Acidic copolymers of the poly(-hydroxy-acid) type containing -malic acid (hydrophilic) and -malic acid benzyl ester (hydrophobic) repeating units in various proportions are prepared by two differentes routes : — catalytic hydrogenolysis of the benzyl ester bonds of homopoly(-malic acid benzyl ester) and — chemical coupling of benzyl alcohol to poly(-malic acid). In attempts to account for the route-dependence of the physico-chemical properties of resulting copolymers, GPC in aqueous medium and measurements of the solubility of Yellow OB, a lipophilic dye, in aqueous solutions have been carried out. The results are discussed in regard to the sequence distributions of hydrophilic and hydrophobic repeating units.     

Bio-Based Degradable Poly(ether-ester)s from Melt-Polymerization of Aromatic Ester and Ether Diols

Vanillin, as a promising aromatic aldehyde, possesses worthy structural and bioactive properties useful in the design of novel sustainable polymeric materials. Its versatility and structural similarity to terephthalic acid (TPA) can lead to materials with properties similar to conventional poly(ethylene terephthalate) (PET). In this perspective, a symmetrical dimethylated dialkoxydivanillic diester monomer (DEMV) derived from vanillin was synthesized via a direct-coupling method. Then, a series of poly(ether-ester)s were synthesized via melt-polymerization incorporating mixtures of phenyl/phenyloxy diols (with hydroxyl side-chains in the 1,2-, 1,3- and 1,4-positions) and a cyclic diol, 1,4-cyclohexanedimethanol (CHDM). The polymers obtained had high molecular weights (M_w = 5.3–7.9 × 10⁴ g.mol⁻¹) and polydispersity index (Đ) values of 1.54–2.88. Thermal analysis showed the polymers are semi-crystalline materials with melting temperatures of 204–240 °C, and tunable glass transition temperatures (T_g) of 98–120 °C. Their 5% decomposition temperature (T_d,5%) varied from 430–315 °C, which endows the polymers with a broad processing window, owing to their rigid phenyl rings and trans-CHDM groups. These poly(ether-ester)s displayed remarkable impact strength and satisfactory gas barrier properties, due to the insertion of the cyclic alkyl chain moieties. Ultimately, the synergistic influence of the ester and ether bonds provided better control over the behavior and mechanism of in vitro degradation under passive and enzymatic incubation for 90 days. Regarding the morphology, scanning electron microscopy (SEM) imaging confirmed considerable surface degradation in the polymer matrices of both polymer series, with weight losses reaching up to 35% in enzymatic degradation, which demonstrates the significant influence of ether bonds for biodegradation.     

Physicochemical basis of the sol-gel process giving selective layers of ultrafiltration ceramic membranes from zirconia hydrosol

Selective layers of ceramic ultrafiltration membranes were prepared by the sol-gel method using zirconia hydrosol as the initial material. On the basis of turbidimetric investigations, a compatibility diagram was constructed in the zirconia (sol) — polymer thickener — water system. The results of x-ray phase analysis and thermogravimetric analysis were used to choose the regime for heat treatment of the sol — polymer thickener compositions in order to prepare selective layers. The characteristics of the pore structure of the selective layers meet the requirements imposed on ultrafiltration membranes.     

Partly alcoholized poly(vinyl acetate) polymers: Properties of polymers hydrolysed by different routes

Several polymers have been prepared over the entire compositional range of poly(vinyl acetate—alcohol) intramolecular mixtures by each of three routes — saponification with alkali, base-catalysed transesterification with methanolic methoxide, and acid-catalysed equilibration with acetic acid and hydrochloric acid mixtures. The polymers prepared by the three routes showed contrasting behaviour in their reaction with iodine in the presence of iodide and in their melting. The results are interpreted in terms of a linear block structure of acetate groups being required for high efficiency in iodine-complex formation and an attendant linear block structure of alcohol groups being required for high crystallinity and high melting-point. The order of degree of block structure in the polymeric products by the three routes is as follows — saponification, high; transesterification, intermediate; acid-equilibrium, hardly any. The use of the iodine complex for the analytical determination of samples from this system is discussed.     

Synthesis and characterization of new poly(siloxysilanes)

The efficient synthesis of two new monomers, vinyltris(dimethylsiloxy)silane (2) and tris(dimethylvinylsiloxy)silane (3), was developed. Hydrosilation of these new A–B₃ monomers affords highly branched starburst poly(siloxysilane) polymers. Polymerization of2 yields a polymer structure that has siliconhydride functional groups on the outer sphere. Polymerization of3 yields a polymer that has the same hyperbranched poly(siloxysilane) core as the polymer produced from2, but the outer sphere contains vinyl moieties. The presence of silicon-hydride or vinyl groups on the surface of both polymers allows functionalization of these materials with a wide variety of reagents.Presented at the XXVIth Silicon Symposium, Indiana University—Purdue University at Indianapolis, March 26–27, 1993.     

Effect of Nano-Sized Poly(Butyl Acrylate) Layer Grafted from Graphene Oxide Sheets on the Compatibility and Beta-Phase Development of Poly(Vinylidene Fluoride) and Their Vibration Sensing Performance

In this work, graphene oxide (GO) particles were modified with a nano-sized poly(butyl acrylate) (PBA) layer to improve the hydrophobicity of the GO and improve compatibility with PVDF. The improved hydrophobicity was elucidated using contact angle investigations, and exhibit nearly 0° for neat GO and 102° for GO-PBA. Then, the neat GO and GO-PBA particles were mixed with PVDF using a twin screw laboratory extruder. It was clearly shown that nano-sized PBA layer acts as plasticizer and shifts glass transition temperature from −38.7 °C for neat PVDF to 45.2 °C for PVDF/GO-PBA. Finally, the sensitivity to the vibrations of various frequencies was performed and the piezoelectric constant in the thickness mode, d₃₃, was calculated and its electrical load independency were confirmed. Received values of the d₃₃ were for neat PVDF 14.7 pC/N, for PVDF/GO 20.6 pC/N and for PVDF/GO-PBA 26.2 pC/N showing significant improvement of the vibration sensing and thus providing very promising systems for structural health monitoring and data harvesting.