Vinyl acetate

About: Vinyl acetate is a research topic. Over the lifetime, 15970 publications have been published within this topic receiving 162142 citations. The topic is also known as: Ethenyl acetate & Ethenyl ethanoate.

Process for the use of vinyl acetate-ethylene copolymer emulsions to adhere fibers to carpet backing

Abstract: Use of vinyl acetate-ethylene copolymer emulsions as laminating adhesives for rug backing is disclosed. The copolymer emulsions are prepared by admixing vinyl acetate-ethylene copolymer, dispersant and thickening agent together, with or without the addition of filler. The vinyl acetate-ethylene copolymer can contain between about 20 and about 70 parts by weight of vinyl acetate and between about 30 and about 80 parts by weight of ethylene. The resulting vinyl acetate-ethylene copolymer emulsions have a glass transition temperature (T g ) of between about -35° C. and about -10° C.

MALDI SpiralTOF high-resolution mass spectrometry and Kendrick mass defect analysis applied to the characterization of poly(ethylene-co-vinyl acetate) copolymers.

Abstract: Rationale Poly(ethylene-co-vinyl acetate) copolymers – usually referred to as EVA – are first class industrial polymers used for applications ranging from padding to photovoltaics as encapsulant for the silicon solar cells. Various techniques have been used for their characterization but the analysis of intact EVA chains using mass spectrometry (MS) has not been reported so far. Methods Three copolymers containing 18, 25 and 40 wt% vinyl acetate (VA) have been characterized using an off-line coupling of size-exclusion chromatography (SEC) and matrix-assisted laser desorption/ionization (MALDI) spiral-time-of-flight (TOF) high-resolution mass spectrometry (HRMS). The representativeness of those results for the entire samples has been checked using 13C NMR spectroscopy. Lastly, Kendrick mass defect analysis has been proposed as an alternative and user-friendly data treatment method. Results The shortest chains isolated by SEC fractionation and mass-analyzed by HRMS have been thoroughly described in terms of end-groups (found to be hydrogens) and co-monomeric composition. The VA content was successfully derived from the peak assignments in MS spectra for the EVA 40 wt% and 25 wt% while it tended to be overestimated for the latest EVA 18 wt% (increasing poly(ethylene) character). Similar results have been found using a faster data treatment method relying on the Kendrick mass defect analysis of the MS data. Conclusions EVA low molecular weight intact oligomers have been extensively characterized by MS for the first time and the structural features confidently extended to the full sample according to NMR data. The Kendrick mass analysis finally constituted an efficient method for a fast evaluation of their VA content with no need for manual assignment. © 2016 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd.

Production of Catalyst-Free Hyperpolarised Ethanol Aqueous Solution via Heterogeneous Hydrogenation with Parahydrogen.

Abstract: An experimental approach for the production of catalyst-free hyperpolarised ethanol solution in water via heterogeneous hydrogenation of vinyl acetate with parahydrogen and the subsequent hydrolysis of ethyl acetate was demonstrated. For an efficient hydrogenation, liquid vinyl acetate was transferred to the gas phase by parahydrogen bubbling and almost completely converted to ethyl acetate with Rh/TiO2 catalyst. Subsequent dissolution of ethyl acetate gas in water containing OH− ions led to the formation of catalyst- and organic solvent-free hyperpolarised ethanol and sodium acetate. These results represent the first demonstration of catalyst- and organic solvent-free hyperpolarised ethanol production achieved by heterogeneous hydrogenation of vinyl acetate vapour with parahydrogen and the subsequent ethyl acetate hydrolysis.

Detergent dispenser pouch made of cold water-soluble PVA containing acetalized units

Abstract: A pouched powder detergent is disclosed which comprises a powder detergent and a pouch containing the powder detergent, wherein the pouch comprises a cold water-soluble polyvinyl alcohol derivative containing 70 to 90 mole % of vinyl alcohol units, 0 to 2 mol % of vinyl acetate units and 10 to 30 mol % of acetalized vinyl alcohol units having an alkyl group containing 034 to 170 carbon atoms on the average, and having a viscosity-average polymerization degree of 200 to 500 with respect to the vinyl monomer units

Synthesis and Biocompatibility of Maleic Anhydride Copolymers: 1. Maleic Anhydride–Vinyl Acetate, Maleic Anhydride–Methyl Methacrylate and Maleic Anhydride–Styrene†

Abstract: A series of maleic anhydride (MA)-vinyl acetate (VA), MA-methyl methacrylate (MM) and MA-styrene (S) copolymers were prepared and characterized. By employing various amounts of initiator, MA-VA, MA-MM and MA-S copolymers with molecular weights ranging between 18000 and 219000 were obtained. The 'in vivo' and'in vitro' tests performed on K562 cellular cultures (human chronic myeloid leukaemia) and also on Westar rats (inoculated with the Walker 256 carcinosarcome) showed that, as a function of the molecular weight, the copolymers synthesized had a 50% in vitro cytotoxicity and a mean tumour regression of a maximum of 68%.