Modification of poly(vinyl chloride) with sodium salts of triazoles

New copolymers containing reactive vinyltriazole units and polyvinylene blocks with conjugation system promising as materials with special electrical, physical, catalytic, and sorption properties have been prepared by the reaction of poly(vinyl chloride) with sodium salts of 1,2,4-triazole and 1,2,3-benzotriazole in a dimethylformamide medium.     

Synthesis and characterization of graft copolymers of poly(vinyl chloride) with styrene and (meth)acrylates by atom transfer radical polymerization

Graft copolymers of poly(vinyl chloride) with styrene and (meth)acrylates were prepared by atom transfer radical polymerization. Poly(vinyl chloride) containing small amount of pendent chloroacetate units was used as a macroinitiator. The formation of the graft copolymer was confirmed with size exclusion chromatography (SEC), ¹H NMR and IR spectroscopy. The graft copolymers with increasing incorporation of butyl acrylate result in an increase of molecular weight. One glass transition temperature (T_g) was observed for all copolymers. T_g of the copolymer with butyl acrylate decreases with increasing content of butyl acrylate.     

Synthesis,polymerization, and copolymerization of multimethacrylate in matrix of poly(vinyl alcohol)

By reacting poly(vinyl alcohol) (PVA) with methacryloyl chloride, multimethacrylate in PVA matrix has been obtained. Free-radical polymerization of multimethacrylate and copolymerization of two multimethacrylates in PVA and p-cresol-formaldehyde matrices in diluted solutions occurs probably along ordered methyl methacrylate units in the matrix and results mainly in ladder-type homopolymer and copolymer. The structures of multimethacrylate, homopolymer, and copolymer have been found on the basis of elemental analysis, IR, and ¹H NMR spectra, and examination of the products of hydrolysis.     

γ-Ray-induced copolymerization of ethylene and vinyl chloride in liquid carbon dioxide

The γ-ray-induced copolymerization of ethylene and vinyl chloride with the use of liquid carbon dioxide as a solvent was studied under a total pressure of 400 kg/cm², with a dose rate of 2.5 × 10⁴ rad/hr at 30°C. A rubberlike, sticky polymer is obtained when the molar concentration of vinyl chloride is less than 30% in the monomer mixture, and the polymer is a white powder at higher concentrations of vinyl chloride. Infrared, x-ray, and differential thermal analyses confirm that the polymerization products are noncrystalline, true random copolymers. The rate of copolymerization decreases markedly when a small amount of vinyl chloride is added to ethylene monomer. In the range of vinyl chloride concentration higher than 5%, however, the rate and the molecular weight of copolymer increase with increasing concentration of vinyl chloride. It has been concluded from kinetic considerations based on these results that the rate of initiation increases proportionally with the concentration of vinyl chloride. Further, the growing chain radicals are shown to be deactivated by the cross-termination reaction between the radicals with terminal unit of ethylene and vinyl chloride, and no transfer reaction occurs.     

INTERPOLYMER ASSOCIATION OF ACRYLAMIDE COPOLYMERS WITH POLY(ETHYLENEIMINE): STABILITY,THERMODYNAMIC PARAMETERS,AND THEIR CORRELATION WITH THE COPOLYMER MICROSTRUCTURE

Acrylamide/vinyl acetate and acrylamide/vinyl propionate copolymers were prepared by solution polymerization using benzoyl peroxide as the initiator. The copolymer composition was determined from the percent nitrogen in the copolymers.

The stability constants and related thermodynamic parameters (e.g., ΔG°, ΔH°, and ΔS°,) of the interpolymer complexes with Poly(ethyleneimine) were determined by using Osada's method. These parameters have been correlated with the sequence distribution of monomer units in the copolymer chains which were obtained from ¹³C{¹H} NMR spectroscopy. The sequence distribution of the comonomer units in the copolymer chains influence the association between the copolymers and the polyelectrolyte which is reflected on the stability of the interpolymer complexes.     

13C-NMR study of chlorinated ethylene–vinyl acetate copolymers

¹³C-NMR has been used to analyze the microstructures of a series of experimental chlorinated ethylene–vinyl acetate copolymers (15–56% CI). Previously established line assignments for EVA copolymers and substituent effect parameters for chlorine have enabled us to tentatively assign partial structures up to five carbon atoms in length. The ¹³C-NMR analyses of a commercial vinyl chloride–vinyl acetate copolymer, a commercial vinyl chloride–vinyl acetate–ethylene terpolymer, and a commercial chlorinated polyethylene support the structural assignments. Data obtained for the experimental resins indicate that the acetate groups influence the way in which chlorine is added to the polymer chain. furthermore, the data indicate the acetate groups undergo little, if any, chlorination.     

Copolymerization of 1-Vinyl-4,5,6,7-tetrahydroindole with Vinyl Chloride in the Presence of a Radical Initiator

Copolymerization of 1-vinyl-4,5,6,7-tetrahydroindole with vinyl chloride in the presence of azobis(isobutyronitrile) occurs as a two-step process. The copolymer is initially formed by the radical mechanism. Then, the eliminated hydrogen chloride initiates cationic oligomerization of 1-vinyl-4,5,6,7-tetrahydroindole, enriching the copolymer with units of this monomer.     

Copolymerization of methyl methacrylate with 36Cl-vinyl chloride

Procedures for assay of radioactivity in vinyl chloride in the gas phase and in solutions of VC copolymers, copolymerizations of ³⁶Cl-vinyl chloride with methyl methacrylate, and determinations of reactivity ratios for the VC-MMA system are reported. The procedures are applicable to other VC copolymer systems.     

NMR Determination of the Microstructure of Polyvinyl Chloride Sulfone). II. 13C-(1H) Spectra

The ¹³C-(¹H) NMR spectra of poly(vinyl chloride sulfone)s with macroscopic compositions corresponding to the ratio vinyl chloride (V):SO₂(S) = n from ca. 1 to 4 have been analyzed in terms of comonomer sequences and configurational placements. In the copolymer with n ? 1, methylene and methine carbons in SVS sequences were resolved and were sensitive to “across SO₂” tacticity. No SVS sequences were observed in the copolymer with n = 2.0, confirming that it had a regular SVVS structure, which also showed a high “internal” stereosequence regularity. It was not possible to discriminate the methylene or methine carbon atoms in S(V)_n S sequences with n ≥ 2.     

Grafting of polymers onto a carbon‐fiber surface by ligand‐exchange reaction of poly(vinyl ferrocene‐co‐vinyl monomer) with polycondensed aromatic rings of the surface

To improve the surface of carbon fiber, the grafting reaction of copolymer containing vinyl ferrocene (VFE) onto a carbon‐fiber surface by a ligand‐exchange reaction between ferrocene moieties of the copolymer and polycondensed aromatic rings of carbon fiber was investigated. The copolymer containing VFE was prepared by the radical copolymerization of VFE with vinyl monomers, such as methyl methacrylate (MMA) and styrene, using 2,2′‐azobisisobutyronitrile as an initiator. By heating the carbon fiber with poly(VFE‐co‐MMA) (number‐average molecular weight: 2.1 × 10⁴) in the presence of aluminum chloride and aluminum powder, the copolymer was grafted onto the surface. The percentage of grafting reached 46.1%. On the contrary, in the absence of aluminum chloride, no grafting of the copolymer was observed. Therefore, it is considered that the copolymer was grafted onto the carbon‐fiber surface by a ligand‐exchange reaction between ferrocene moieties of the copolymer and polycondensed aromatic rings of carbon fiber. The molar number of grafted polymer chain on the carbon‐fiber surface decreased with increasing molecular weight of poly(VFE‐co‐MMA) because the steric hindrance of grafted copolymer on the carbon‐fiber surface increases with increasing molecular weight of poly(VFE‐co‐MMA). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1868–1875, 2002     

Grafting reactions of vinyl acetate onto poly[(vinyl alcohol)-co-(vinyl acetate)]

The grafting preference of vinyl acetate onto the methine carbon of poly(vinyl alcohol) (PVOH) versus the acetate group of poly(vinyl acetate) (PVAc) was determined as part of an attempt to prepare novel branched PVOH from partially hydrolyzed PVAc. The results showed long chain grafting on the acetate groups of the PVAc units rather than the methine carbons of the PVOH or PVAc units. Decreasing the monomer or initiator concentration decreased the molecular weight of the graft copolymer formed. Of the initiators studied, ammonium persulfate gave the largest increase in copolymer molecular weight. Both hydrolysis and reacetylation combined with gel permeation chromatography (GPC) and ¹³C-NMR of the fully hydrolyzed material were used to estimate the number and location of grafts. © 1996 John Wiley & Sons, Inc.     

Chemical and electrochemical grafting of polyaniline onto poly(vinyl chloride): synthesis,characterization, and materials properties

We have designed and developed a new strategy for the chemical and electrochemical graft copolymerization of aniline onto poly(vinyl chloride). For this purpose, first phenylamine groups were incorporated into poly(vinyl chloride) via a nucleophilic substitution reaction in the presence of a solvent composed of 4‐aminophenol, potassium carbonate, and dry N,N‐dimethylformamide at room temperature, in order to avoid cross‐linking. The macromonomer obtained was used in chemical and electrochemical oxidation copolymerization with aniline monomer to yield a poly(vinyl chloride)‐g‐polyaniline (PVC‐g‐PANI) graft copolymer. The chemical structures of samples as representatives were characterized by means of Fourier transform infrared and ¹H nuclear magnetic resonance spectroscopies. The electroactivity behaviors of the synthesized samples were verified under cyclic voltammetric conditions. The electrical conductivity and electroactivity measurements showed that the PVC‐g‐PANI graft copolymer has lower electrical conductivity as well as electroactivity than those of the pure PANI. However, the lower electrical conductivity and electroactivity levels in this material can be improved at the price of solubility and processability. Moreover, the thermal behavior and chemical composition of the synthesized graft copolymer were investigated. Copyright © 2016 John Wiley & Sons, Ltd.     

Vinyl Chloride-Vinyl Bromide Copolymers

Abstract

Radical copolymerization kinetics of vinyl chloride (VC) and vinyl bromide (VB) lead to the following reactivity ratios r_VC=0.825 r_VB=1.05 Vinyl bromide acts as a chain transfer agent, more powerful than vinyl chloride, the transfer constant for VC radicals being 8.5 × 10^?3 at 40° C. Neither thermal nor ionic degrad-ation produce controlled distribution of short diene sequences in the copolymer. In the ionic process initiated with LiCl or LiBr in dimethylformamide solution, substitution of halogen atoms as well as acid elimination takes place.     

The dechlorination of poly(vinyl chloride) by zinc and tributyl tin hydride.: Characterization of the product microstructures by carbon-13 NMR

Poly(vinyl chloride) has been reacted with zinc in refluxing dioxane for times in the range 18–113 h. The structure of the polymeric product has been examined by ¹H and ¹³C NMR spectroscopy. Contrary to earlier predictions, the reaction does not proceed only by 1,3-chlorine elimination to form cyclopropyl rings. Double bonds and methylene units are formed also, to give a polymer of considerable structural complexity. This complexity can be reduced by replacement of remaining chlorine with hydrogen after treatment with tributyl tin hydride. Analysis of the fully dechlorinated polymer shows that cyclopropyl rings are distributed randomly with a trans/cis ratio of about 2.6. A small number of cyclopentyl rings is observed also. A maximum of 9% of the original vinyl chloride units are dehydrochlorinated to give unconjugated vinylene units with a predominantly trans structure.     

Photoconductive copolymers containing N-vinylcarbazole

The synthesis of N-vinylcarbazole (VCbz) copolymers in which electron-accepting groups are incorporated into the polymer chain is reported. The acceptors were introduced by appropriate reactions of VCbz–vinyl acetate or VCbz–acryloyl chloride copolymers and consisted of 3,5-dinitrobenzoyl, 2,4-dinitrophenyl acrylate, β-2,4-dinitrophenoxy propionate, and trichlorobenzoquinone units. The copolymer containing the 3,5-dinitrobenzoyl units required no chloranil as a dopant to be photoconductive, and in fact showed a slightly improved photoresponse relative to conventional poly VCbz doped with external chloranil.     

Alternating Sequence Control for Carboxylic Acid and Hydroxy Pendant Groups by Controlled Radical Cyclopolymerization of a Divinyl Monomer Carrying a Cleavable Spacer

By utilizing features of the hemiacetal ester (HAE) bond: easy formation from vinyl ether and carboxylic acid and easy cleavage into different functional groups (‐COOH and ‐OH), we achieved control of the alternating sequence of two functional pendant groups of a vinyl copolymer. Methacrylate‐ and acrylate‐based vinyl groups were connected through HAE bonds to prepare a cleavable divinyl monomer, which was cyclo‐polymerized under optimized conditions in a ruthenium‐catalyzed living radical polymerization. Subsequent cleavage of the HAE bonds in the resultant cyclo‐pendant led to a copolymer consisting of alternating methacrylic acid and 2‐hydroxyethyl acrylate units as analyzed by ¹³C NMR spectroscopy. The alternating sequence of ‐COOH and ‐OH pendants specifically provided a lower critical solution temperature (LCST) in an ether solvent, which was not observed with the random copolymer of same composition ratio.     

Cationic copolymerization of 2-vinyl-1,3-dioxane with styrene and 1,3-dioxolane

Copolymerization of 2-vinyl-1,3-dioxane with styrene and 1,3-dioxolane was carried out in methylene chloride at 0°C with triethyloxonium tetrafluoroborate as an initiator. Random copolymers were obtained from both of these monomer pairs, but attempted copolymerization of 2-vinyl-1,3-dioxane with 3,3-bis(chloromethyl)oxetane under similar conditions resulted in the homopolymer of the latter monomer. There were three structural units of 2-vinyl-1,3-dioxane in these copolymers as in its homopolymer: the “ester” unit, which was formed by vinyl addition with hydride shift followed by ring-opening rearrangement, the “vinyl” unit produced by ring-opening reaction, and the unit with a pendant 1,3-dioxane ring formed by simple vinyl addition. The fractions of the ester and vinyl units to the total 2-vinyl-1,3-dioxane units in the copolymer of 2-vinyl-1,3-dioxane with styrene decreased with decreasing 2-vinyl-1,3-dioxane content. On the contrary, the fraction of the vinyl unit in the copolymer of 2-vinyl-1,3-dioxane with 1,3-dioxolane increased slightly with decreasing 2-vinyl-1,3-dioxane content, while that of the ester unit decreased. The reactivities of the propagating species are discussed on the basis of these results.     

Gamma Ray Induced Gaseous Phase Polymerization and Copolymerization of Vinyl Monomers in Bagasse

Gamma-ray induced gaseous phase in situ polymerization of vinyl chloride and copolymerization of vinyl chloride with vinyl acetate in bagasse have been investigated and discussed. The prepared bagasse-plastic combinations were not improved of its mechanical strength owing to the deposited PVC powder and the low copolymer loading in bagasse-board. The viscosity average molecular weight of PVC formed in bagasse-board was found to be slightly higher than that of PVC formed in the in situ liquid polymerization system. No graft reaction of PVC onto bagasse cellulose was observed, while low grade of graft reaction was confirmed with PVC-PVAc copolymer system.     

Analysis of copolymer surfaces by surface reactions and XPS

Summary The adsorption of polar groups at the polymer melt/mould interface is detected by chemical analysis. Vinyl alcohol groups and vinyl acetate groups (after hydrolysis) react with heptafluoro-butanoic acid chloride to attach a fluorine-containing molecular group to the surface. By measuring fluorine and other elements with XPS the surface composition is determined. On a gold substrate vinyl alcohol groups are adsorbed in a copolymer of vinyl chloride, vinyl acetate and vinyl alcohol. If a vinyl chloride-vinyl acetate copolymer is compression moulded against gold, the polymer surface energy is increased by adsorption of vinyl acetate groups. Subsequent relaxation, after removal of the substrate, leads to slow desorption of vinyl acetate groups. At the interface of the vinyl chloride-vinyl acetate copolymer with nickel or aluminium the polymer is oxidized.

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Zusammenfassung Die Adsorption von polaren Gruppen an der Polymerschmelze/Substrat — Grenzfläche wird chemisch analysiert. Vinylalkohol- und Vinylazetatgruppen in Oberflächen von Copolymeren reagieren (nach Hydrolyse) mit Heptafluorbuttersäurechlorid. Mit XPS (X-ray-Photoelectron-Spectroscopy) messen wir die Fluormenge, um die Oberflächenzusammensetzung zu bestimmen. In PVC/Ac/Alc Copolymerem adsorbieren Vinylalkoholgruppen an ein Goldsubstrat. Die Zunahme der Oberflächenenergie von PVC/Ac durch Schmelzen auf einer Goldoberfläche und die spätere Relaxation, werden verursacht durch Adsorption und Desorption von Vinylazetateinheiten. Bei Gebrauch von Nickel oder Aluminium wird die Polymeroberfläche oxydiert.

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With 3 tables     

Self-organizing cyclolinear methylcyclohexasiloxane polymers carrying reactive vinyl groups

Atactic cyclolinear organosilicon polymers containing vinyl substituents in RSiO_1.5, R₂SiO or both moieties have been synthesized through the heterofunctional polycondensation of trans,cis-2,8-dihydroxymethyl(vinyl)cyclohexasiloxanes with 2,8-dichloromethyl(vinyl)cyclohexasiloxanes. The structure of the polymers has been studied by ¹H and ²⁹Si NMR and IR spectroscopy, molecular mass measurements, and elemental analysis. The phase behavior of these copolymers in the bulk has been examined by DSC, X-ray diffraction, and polarization optical microscopy. It has been shown that the copolymer can exist in the mesomorphic state in the temperature range from ?100 to +200°C. The X-ray data indicate changes in the interlayer spacing and the type of packing of cyclolinear poly(methylvinylsiloxanes) with an increase in the content of vinyl substituents in the repeating units of the polymer. The ability of cyclolinear poly(methylvinylsiloxanes) to spread over the water/air interface and to form mono-and multilayers has been investigated. As the content of vinyl substituents in the polymer unit is increased to two or four, the ability of polymers to form multilayers is preserved. The incorporation of vinyl substituents into RSiO_1.5 or R₂SiO moieties of polymer units is accompanied by the formation of monolayers.