Vinyl Alcohol Units Research Articles

Builder performance in detergent formulations and biodegradability of poly(sodium carboxylate) containing vinyl alcohol groups

Two series of poly[(disodium fumarate)co‐(vinyl alcohol)] and poly[(disodium maleate)‐co‐(vinyl alcohol)], containing vinyl alcohol moieties as biodegradable segments in the polymer chain, were prepared and evaluated for builder performance in detergent formulations as well as for their biodegradability. From the biological oxygen demand test and gel permeation chromatography of the polymer in the biodegradation test media, it was found that biodegradability of the copolymers was dependent on the content of vinyl alcohol moieties in the polymer chain. Significant degradation was observed for fumarate copolymers containing more than 75% vinyl alcohol units and for maleate copolymers containing more than 88≈99% vinyl alcohol units in the copolymer chain. The decisive factor for rapid degradation of the polymer by polyvinyl alcohol (PVA)‐degrading microbes seems to be the chainlength of the successive vinyl alcohol groups in the polymer chain. A definite chainlength is needed to become a substrate for the PVA‐degrading enzyme. For rapid biodegradation to occur, a copolymer containing more than about five to seven successive vinyl alcohol blocks is needed. Builder performance in the detergent formulation is dependent on the content of carboxylate groups in the polymer. Polymers with high carboxylate content showed better detergency, and the fumarate copolymer was more effective than the maleate copolymer. Detergency performance improved greatly with increasing amounts of polymeric builder used in the detergent formulation.

Gas transport in poly(vinyl methylbenzoates)

AbstractPermeation of eight gases (He, Ne, Ar, Kr, O2, N2, CO2, and CH4) in three isomeric poly(vinyl methylbenzoates) was measured by the time‐lag method, and the effects of the shape of side groups on gas transport in the polymers were investigated. The p‐methylphenyl side group of poly(vinyl p‐methylbenzoate), which increases both interchain and intrachain distances, caused an increase in gas diffusivity. The diffusivity and density data were consistent with free volume theory. Two other isomeric polymers, poly(vinyl o‐methylbenzoate) and poly(vinyl m‐methylbenzoate), had lower gas diffusivities than poly(vinyl p‐methylbenzoate) and poly(vinyl benzoate). The o‐methyl and m‐methyl groups on the phenyl ring were found to hinder gas diffusion, i.e., decrease the free volume. In contrast, the solubility of the gases in all these polymers was similar because of their similar chemical structures. The effects of hydroxyl groups also were investigated by the use of poly(vinyl m‐methylbenzoate) containing a small number of vinyl alcohol units. The decrease in gas diffusivity was attributed to the decrease of free volume due to hydrogen bonding, but the change of gas solubility was still negligible.

The Reactivity of Hydroxyl Groups at Different Tactic Sequences on Poly(vinyl alcohol) in the Addition Reaction with Vinyl Sulfoxides and Vinyl Sulfones

The reactivity of hydroxyl groups in different tactic sequences on poly(vinyl alcohol) was studied in the Michael type addition reaction with vinyl sulfoxides and vinyl sulfones. By the 13C NMR anaysis on the methine carbon signal in unreacted vinyl alcohol units for the obtained sulfinylethyl and sulfonylethyl poly(vinyl alcohol)s, it was concluded that the reactivity order of hydroxyl groups in different tractic sequences was isotactic>heterotactic>syndiotactic.

Sorption of Volatile Compounds in Aqueous Solution by Ethylene‐Vinyl Alcohol Copolymer Films

ABSTRACTSorption of volatile compounds by ethylene‐vinyl alcohol copolymer (EVOH) films from an aqueous solution was investigated to evaluate the merit of their use for food packaging. With regard to EVOH, equilibrium swelling values gave rise to a bimodal solubility parameter distribution with maxima at δ values of 8.5 assigned to ethylene units and 14.5 to vinyl alcohol units. Comparing distribution ratios of EVOH with those of middle‐density polyethylene (MDPE), the ratios were 1:100 for terpene hydrocarbons, 1:10 for esters, 1:2 for alcohols, and almost 1:1 for aldehydes. By biaxial orientation of EVOH film, the sorption could be depressed below 60%. These results suggested EVOH films are more appropriate than MDPE for food container lining.

Gemischt ionisch und elektronisch leitende derivate des polyvinylalkohols

By reacting poly(vinylalcohol) with elemental bromine in aqueous solution a partially oxidized copolymer of vinyl alcohol, β-bromo-vinyl alcohol, ketene, and bromo-ketene units obtained, which on treatment with aqueous alkali hydroxide yield salts with electric and ionic conductivity ( K 140°C⩽10 −3S cm −1).

Miscibility of mixtures from partially hydrolyzed poly(vinyl acetate) and poly(N‐vinyl‐2‐pyrrolidone)

AbstractPolymers with different compositions of vinyl alcohol and vinyl acetate units (P(VA‐VAc)), obtained by alcoholysis of poly(vinyl acetate) with sodium methoxide, were mixed with poly(N‐vinyl‐2‐pyrrolidone) (PVP). The miscibility was studied observing glass transition temperatures by differential scanning calorimetry (DSC). The calorimetric results indicate that for vinyl alcohol unit contents in P(VA‐VAc) of roughly 70 wt.‐% or more, P(VA‐VAc)/PVP blends are fully miscible, whereas blends obtained from P(VA‐VAc) with vinyl alcohol contents lower than the above mentioned values are only partially miscible or even immiscible. The miscibility is attributed to hydrogen bond interactions between hydroxyl groups in P(VA‐VAc) and the carbonyl group of PVP.

Preparation of copoly(vinyl alcohol‐styrenesulfonic acid) resin and its catalytic activity on hydrolysis of carbohydrates. III. Kinetic analysis of the catalysis

AbstractHydrolysis of dextrin in the presence of copoly(vinyl alcohol‐styrenesulfonic acid) resin was investigated kinetically. The hydrolysis rate increased nearly proportionally with increases in the concentrations of the substrate and the catalyst copolymer. This is in contrast to the results found in a similar homogeneous reaction in the presence of soluble copoly(vinyl alcohol–styrenesulfonic acid) in which the reaction rate clearly followed Michaelis–Menten type kinetics. However, the hydrolysis was inhibited by the addition of copoly(vinyl alcohol–styrene) resin or poly(vinyl alcohol). Activation parameters of the hydrolysis in the presence of the copolymer resin as catalyst were also investigated, and it was found that the enthalpy and entropy of the activation in the presence of the copolymer resin were lower than those in Amberlite 120B and slightly decreased when vinyl alcohol unit was introduced. From these results it was concluded that the poly(vinyl alcohol) sequence introduced into the insoluble catalyst copolymer resin also played an important part in the acceleration of dextrin hydrolysis in a manner similar to the case of a soluble catalyst, although the interaction with the substrate was weaker.

Preparation of copoly(vinyl alcohol–styrenesulfonic acid) resin and its catalytic activity on hydrolysis of carbohydrates. II. Two-step polymerization using tetraethylthiuram disulfide as an initiator

Copoly(vinyl alcohol–styrenesulfonic acid) resin was prepared by a two-step polymerization, consisting of a suspension polymerization of styrene containing divinylbenzene using tetraethylthiuram disulfide as an initiator and a subsequent block copolymerization of vinyl acetate to the crosslinked polystyrene obtained, followed by sulfonation and saponification. Some reaction conditions in the polymerization of styrene were investigated to obtain copolymer containing more vinyl alcohol units. The catalytic activity of the copolymer on the hydrolysis of dextrin was investigated and found to be increased with increasing amount of vinyl alcohol units and with a lowering degree of crosslinking of the copolymer. The maximum acceleration of rate obtained in the presence of the copolymer was about six times that in the presence of Amberlite 120B. Catalytic activity of the copolymer on hydrolysis of sucrose and methyl acetate were also investigated and found to be comparable each other and lower than that for dextrin. The difference between the activities for dextrin and for sucrose and methyl acetate increased with an increasing amount of vinyl alcohol units in the copolymer.

Hydrolysis of dextrin in the presence of block copolymer of vinyl alcohol and styrenesulfonic acid

AbstractA block copolymer of vinyl alcohol and styrenesulfonic acid was prepared by a two‐step polymerization and subsequent modification, and its catalytic activity on the hydrolysis of dextrin was investigated. The hydrolysis rate in the presence of the copolymer containing more vinyl alcohol‐repeating units was found to follow Michaelis–Menten‐type kinetics, whereas that in the presence of a copolymer containing fewer vinyl alcohol units proceeded according to ordinary second‐order kinetics. The process of complex formation for the former system was characterized by pronounced decreases in enthalpy and entropy, although the enthalpy and the entropy of activation for the decomposition of the complex to product was comparable to that of a sulfuric acid‐catalyzed system. The maximum rate enhancement obtained in the present experiment was approximately fivefold on the basis of the reaction in the presence of sulfuric acid at 65°C. The results were compared with those obtained in the presence of a random copolymer catalyst, previously reported.

The color reaction between partially saponified poly(vinyl acetate) and iodine‐iodide in the presence of boric acid

AbstractThe effect of the boric acid concentration on the color reaction between partially saponified poly(vinyl acetate), which is dissolvable in water, and iodine‐iodide was investigated. As the concentration of boric acid increased, the absorbance at λmax = 488 nm of the red‐violet complex, which is due to a long sequence of vinyl acetate units distributed along the polymer chain, increased gradually, reached a maximum, and then decreased from the point in which the absorbance at λmax = 656nm of the blue complex, based on the vinyl alcohol units in the polymer, was observed. The color complex in an excess of boric acid transferred from red‐violet to red‐tinged blue with time. From the color change, the molar absorption coefficient at λmax = 656 nm for the iodine molecule in the blue complex was found to be 3,92.104l/(mol cm).

THE CRYSTALLINITY OF ETHYLENE-VINYLALCOHOL-ACRYLIC ACID TERPOLYMERS

The physical properties and crystal structure of ethylene-vinylalcohol-acrylic acid terpolymer (EVA-AA: 1_??_10mol% AA content) were investigated by X-ray diffraction method and differential scanning calorimetry.Following results were obtained: (1) The degree range of crystallinity of EVA-AA was about 15_??_25% which is lower than that obtained of ethylene-vinyl alcohol copolymer (25_??_50%) notwithstanding their nearly similar vinyl alcohol (VA) content. (2) A crystalline region of EVA-AA was partially decomposed by acrylic acid (AA) units. These AA units localized in the amorphous region of EVA-AA like the AA units in vinyl alcoholacrylic acid and ethylene-acrylic acid copolymer. (3) The data gathered from the melting point, d-spacing and copolymer composition showed that the crystalline region of EVA-AA was composed of VA and Et units and that the VA content of EVA-AA in the crystalline phase differed from the overall VA content of the terpolymer

Polymerization of Benzyl Vinyl Ether with a Ziegler Catalyst and Reaction of Poly(benzyl vinyl ether) with TiCl4

The polymerization of benzyl vinyl ether (BVE) was investigated in toluene by Et3Al–TiCl4 catalyst. When the catalyst preparation and the monomer addition were carried out at 0°C and the reaction mixture was brought to 60°C, an insoluble polymeric product was obtained together with poly(benzyl vinyl ether) (PBVE). This insoluble product was revealed to be a polymer composed of BVE and vinyl alcohol units complexed with titanium compound. This was formed by the reaction of PBVE and TiCl4 in the catalyst system and the subsequent hydrolysis of the reaction product. Poly(vinyl alcohol) (PVA) complexed with a titanium compound was obtained by the reaction of PBVE and TiCl4 in toluene at room temperature. When the molar ratio of TiCl4 to PBVE was above 0.3, PBVE was completely debenzylated and became insoluble by being complexed with a titanium compound. The composition of this product was roughly estimated to be [–{–CH2–CH(OH)–}6– TiCl(OH)3]n. The complexed PVA was soluble only in hydrochloric acid and could be converted to free PVA by reprecipitation from a solution containing acetylacetone.

Stereospecific Polymerization of Allyl Vinyl Ether by BF3·OEt2

Abstract The polymerization of allyl vinyl ether was carried out by means of BF3·OEt2. The reaction proceeded through the vinyl double bond, and a polymer with allyl ether side chains was obtained. The effects of the polymerization conditions on the stereoregularity of the polymer were studied by means of NMR spectroscopy using a spin decoupling technique. A highly isotactic polymer was obtained at −78°C in toluene. The isotacticity of the polymer decreased slightly with a rise in the reaction temperature and with an increase in the initial monomer concentration. When the reaction was carried out in a mixture of toluene and nitroethane, a marked decrease in the isotacticity and the solution viscosity of the polymer was observed with an increase in the amount of nitroethane. The solution viscosity of the polymer decreased with an increase in the polymerization temperature and the catalyst concentration, and increased with an increase in the initial monomer concentration. The reaction between the polymer and HBr in acetic acid yielded a ternary copolymer consisting of vinyl alcohol, vinyl acetate, and vinyl bromide units.

An infrared spectroscopic study of the structure of the butyrals of polyhydroxy compounds

1. The use of the methodological possibilities provided by infrared spectroscopy for the study of a number of butyrals of copolymers of vinyl alcohol and hydroxymethylene has led to the conclusion that it is the hydroxyl groups of the vinyl alcohol units which are the first to undergo acetal formation. 2. On the basis of a study of the products of the thermal oxidation it has been possible to reveal specific features of the degradation of butyrals compared with PVB and hence to determine the structure of the original polymer.

Melting point and heat of fusion of poly(vinyl alcohol)

AbstractDifferential thermal analysis was used to study the effect of a diluent, glycerol, and copolymer units, acetate groups, on the melting point of poly(vinyl alcohol) (PVA). The melting point of PVA was found to be 228°C. and the heat of fusion by the diluent and copolymer methods was 1.64 and 0.56 kcal./mole, respectively, based on vinyl alcohol units. Flory's theory was used as a basis for analysis. The results are compared with literature values for the heat and entropy of fusion of polyethylene, and the differences briefly discussed.

Studies on hydroxyethylpolyvinyl alcohol

AbstractHydroxyethylated polyvinyl alcohols (HEPVA's) containing 12, 19, and 35% combined ethylene oxide were prepared by a heterogeneous reaction between dry polyvinyl alcohol (PVA) and liquid ethylene oxide. Another sample containing 18% was prepared by a more nearly homogeneous reaction in the presence of water. These derivatives may be analyzed satisfactorily by the modified zeisel method of Morgan. The properties of the HEPVA's are briefly described. Reaction of HEPVA with p‐toluenesulfonyl chloride showed that secondary hydroxyls were tosylated along with the primary and that the two reactions cannot be separated kinetically. This method, useful in estimating the primary hydroxyl content of hydroxyethylcellulose, cannot be applied to HEPVA. The stability of the tosylates indicated, however, that in derivatives containing up to 35% combined C2H4O2 ca. 1/2 ethylene oxide per vinyl alcohol unit, no polyethylene glycol chains were present and all combined ethylene oxide existed as individual hydroxyethyl groups distributed along the PVA backbone. Introduction of ethylene oxide into PVA increased the reactivity of residual secondary hydroxyls toward chemical reagents by destroying the normal high degree of hydrogen bonding and making adjacent domains more accessible for reaction. Very noticeable differences in properties were observed between HEPVA's prepared under differing conditions of heterogeneity. Two such polymers of similar ethylene oxide content showed quite different extents of reactions, susceptibility toward swelling agents, and x‐ray diffraction diagrams. These differences are attributed to a more random distribution of hydroxyethyl groups along the PVA backbone in the product of the more homogeneous reaction which leads to a more disordered system.