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.

Surface Properties of Poly(vinyl alcohol) Films Dominated by Spontaneous Adsorption of Ethanol and Governed by Hydrogen Bonding

Abstract: The surface structures of poly(vinyl alcohol) (PVA) films with four different degrees of hydrolysis after immersion in ethanol were investigated using sum frequency generation (SFG) vibrational spectroscopy and contact angle (CA) goniometry. The result showed that the surface chemical structure of the PVA films was strongly dependent on the degree of hydrolysis. The vinyl acetate (VAc) units in the PVA chains resulting from incomplete hydrolysis segregate to the film surface and strongly affect the adsorption behavior of ethanol molecules on their surfaces. The surface hydrophilicity decreased greatly for PVA films with relatively high hydrolysis degrees (i.e., 99% and 97.7%), in which the water contact angle increased by 20°, and increased for PVA with relatively low hydrolysis degrees (95.1% and 84%) after immersion in ethanol. It was found that ethanol molecules adsorb from solution onto a PVA film surface in an ordered and cooperative way governed by hydrogen bonding when the hydrolysis degrees of PVA...

Storm window film comprising at least five layers

Abstract: A five layered thermoplastic film having a desired combination of physical characteristics is disclosed. The film may be utilized to form storm windows. A preferred palindromic embodiment of the film comprises a core layer consisting essentially of either (a) a copolymer of ethylene and vinyl acetate or (b) a three component blend of (a) a linear low density polyethylene, (b) a linear medium density polyethylene and (c) an ethylene vinyl acetate copolymer. The preferred embodiment also comprises two intermediate layers each consisting essentially of a linear low density polyethylene and two surface layers each consisting essentially of a four component blend of (1) a linear low density polyethylene, (2) a linear medium density polyethylene, (3) a copolymer of ethylene and vinyl acetate and (4) one or more light stabilizers. Appropriate slip, antiblock and antioxidant agents may also be present.

DNA cross-links in human leucocytes treated with vinyl acetate and acetaldehyde in vitro.

Abstract: Human leucocytes were incubated in the presence of vinyl acetate or acetaldehyde (10–20 mM) for 4 h at 37°C in vitro. DNA damage was analysed by alkaline elution. None of the compounds induced a detectable increase in the frequency of DNA strand breaks. Cells exposed to 5 Gy of X-ray immediately after treatment and before alkaline elution showed a clear, dose-dependent retardation of the elution rate in comparison with X-irradiated control cells. These results demonstrate that both vinyl acetate and acetaldehyde induce DNA cross-links in human cells.

Solvent effect on radical polymerization of vinyl acetate.

Abstract: Absolute rate constants of vinyl acetate (VAC) polymerization have been measured by using the intermittent illumination method in various aromatic solvents and ethyl acetate at 30°. It was shown that the solvent effect was mainly ascribed to the variation in propagation rate constants (kp) with solvents rather than that in termination rate constants (kt). The kp increased in the order: benzonitrile < ethyl benzoate < anisole < chlorobenzene < fluorobenzene < benzene < ethyl acetate. This order is almost the same as that for vinyl benzoate (VBZ) previously reported. There was about an eightyfold difference between the largest and the smallest values. This large variation in kp is explained neither by copolymerization through solvents nor the chain transfer to solvents, but by a reversible complex formation between the propagating radical and aromatic solvents. The kp was determined in mixed solvents of ethyl benzoate and ethyl acetate, decreasing with increasing content of ethyl benzoate. This result supports the idea of a reversible complex. The stability constants (Ks) of the complex were estimated on the assumption that the complexed radical was in a dormant state and inactive in the polymerization. The correlation between Ks or kp and the calculated delocalization stabilization energy for the complex was found, and supported the explanation for the solvent effect.