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.

Synthesis of Novel Well-Defined Poly(vinyl acetate)-b-poly(acrylonitrile) and Derivatized Water-Soluble Poly(vinyl alcohol)-b-poly(acrylic acid) Block Copolymers by Cobalt-Mediated Radical Polymerization

Abstract: Poly(vinyl acetate)−Co(acac)2 macroinitiators, prepared by cobalt-mediated radical polymerization of vinyl acetate (VAc), were used to synthesize well-defined poly(vinyl acetate)-b-poly(acrylonitrile) (PVAc-b-PAN) block copolymers. Different solvents and temperatures were tested for the polymerization of the acrylonitrile segment by cobalt-mediated radical polymerization (CMRP), and copolymers with low polydispersity were obtained provided that dimethylformamide was used as solvent at 0 °C. The mechanism of control was assumed to change from a degenerative chain transfer mechanism for the VAc polymerization to a reversible-termination process for the AN polymerization. The hydrolysis of the ester groups of the PVAc block and the nitrile groups of the PAN sequence of the copolymer by potassium hydroxide in an ethanol/water mixture provided the double hydrophilic and pH-responsive poly(vinyl alcohol)-b-poly(acrylic acid) block copolymer. Finally, the pH responsiveness of these copolymers was demonstrated by...

Interfacial Interactions and Segmental Dynamics of Poly(vinyl acetate)/Silica Nanocomposites

Abstract: We investigate the interfacial interactions and segmental dynamics of hydrophilic and hydrophobic (calcined) silica nanoparticle (NP) filled poly(vinyl acetate) (PVAc) composites via a combination of Fourier transform infrared spectroscopy (FTIR) and broadband dielectric spectroscopy measurements. For hydrophilic silica NP filled composites, an increase in the amount of bound carbonyl groups with increasing silica loading can be noted due to hydrogen bonding interactions with hydroxyls on the NP surfaces and carbonyl groups of PVAc. It is surprising that the apparent glass transition temperature (Tg) increases very slightly (∼1 K) compared to pure PVAc, but the glass transition process becomes much broader, indicating the existence of a slower relaxation mode. In addition to the bulklike α-relaxation assigned to polymer segments away from the NP surfaces, the nanocomposites also exhibit a slower interfacial α′-relaxation by 3–4 orders of magnitude compared to bulk polymers. However, in the case of hydroph...

First Amphiphilic Poly(vinylidene fluoride-co-3,3,3-^trifluoropropene)-b-oligo(vinyl alcohol) Block Copolymers as Potential Nonpersistent Fluorosurfactants from Radical Polymerization Controlled by Xanthate

Abstract: The synthesis of poly(vinylidene fluoride-co-3,3,3-trifluoropropene)-b-oligo(vinyl alcohol) block copolymers by sequential controlled radical copolymerization of vinylidene fluoride (VDF) and 3,3,3-trifluoropropene (TFP) and of vinyl acetate in the presence of xanthate and their use as original surfactants are presented. First, a fluorinated xanthate C6F13C2H4OC(O)CH(CH3)SC(S)OC2H5 was prepared in two steps from 1H,1H,2H,2H-perfluorooctanol in 67% overall yield. Then, it was successfully involved as a chain transfer agent for the macromolecular design via the interchange of xanthates (MADIX) polymerization of vinyl acetate in a fluorinated solvent in 71% yield, and a good agreement was noted between targeted and experimental molecular weights of poly(vinyl acetate). This fluorinated xanthate was also successfully used in the radical copolymerization of VDF and TFP. Then, these poly(VDF-co-TFP) copolymers bearing a xanthate end group were involved in the controlled radical polymerization of vinyl acetate (...