Vinyl acetate graft copolymers

D. Mnnteanu and S. Turcn, Evaluation of kinetic parameters of the thermal decomposition of polyethylene-vinyl acetate graft copolymers, J. Thermal Anal, 20, 281 (1981). 

Photolabile groups on polymers can serve as sites for photoinitiated graft copolymerizations. For instance, when polymers and copolymers of vinyl ketone decompose in ultraviolet Imht in the presence of acrylonitrile, methyl methacrylate, or vinyl acetate, graft copolymers form ... 

Figure 3. Molecular weight distributions of lignin and lignin-vinyl acetate graft copolymers.

Mixtures of two or more monomers can polymerize to form copolymers. Many copolymers have been developed to combine the best features of each monomer. For example, poly(vinyl chloride) (called a homopolymer because it is made from a single monomers) is brittle. By copolymerizing vinyl chloride with vinyl acetate, a copolymer is obtained that is flexible. Arrangement of the monomer units in a copolymer depends on the rates at which the monomers react with each other. Graft copolymers are formed when a monomer is initiated by free radical sites created on an already-formed polymer chain. 

A vinyl chloride-ethylene-vinyl acetate terpolymer system gives products with superior impact strength suitable for an outdoor environment. The modifier component is a 45% vinyl acetate (EVA) copolymer with PVC grafted on it. EVA modification depends on a network structure. 

The two pottant materials studied in this report are plasticized polyvinyl butyral (plPVB) which is easily available and used in safety glass, and a highly stabilized, peroxide crosslinked ethylene/vinyl acetate (EVA) copolymer containing about 33 weight % vinyl acetate (.7). The outer cover/insulator materials studied include polyvinyl fluoride (PVF) and a butyl aerylate/methyl methacrylate graft copolymer (BAgMMA) both are blown films. 

Ethylene vinyl acetate-vinyl chloride graft copolymer. See EVA/PVC graft polymer Ethylene/vinyl alcohol copolymer CAS 25067-34-9... 

Polyethylene, PE, blended with immiscible polymers (e.g., PVC, PIB, PS) was compatibilized by addition of graft copolymer (e.g., styrene or vinyl acetate grafted on PE)... 

Polyethylene glycol, vinyl acetate, vinyl caprolactam graft copolymer Soluplus 70 1. Newest excipient for HME 2. Low Tg can limit stability 3. Not of compendial status 4. Stable up to 180 °C... 

Blends of PE with PVC have been compatibilized using graft copolymers of ethylene and vinyl chloride, chlorinated polyethylenes (CPE) and ethylene-vinyl acetate (EVA) copolymers. Compatibilized... 

Alkaline methanolysis of graft vinyl acetate-lignin copolymers (Samples LVAO, LVAl, and LVA60) led to the corresponding water-soluble vinyl alcohol copolymers, whose lignin content, as determined by the absorption at 280 nm, resulted to be substantially higher than in the parent VAc copolymer samples hydrolyzed samples, respectively, thus demonstrating however the formation of copolymer macromolecules. 

Gross-Linking. A variety of PE resins, after their synthesis, can be modified by cross-linking with peroxides, hydrolysis of silane-grafted polymers, ionic bonding of chain carboxyl groups (ionomers), chlorination, graft copolymerization, hydrolysis of vinyl acetate copolymers, and other reactions. 

Although they lack commercial importance, many other poly(vinyl acetal)s have been synthesized. These include acetals made from vinyl acetate copolymerized with ethylene (43—46), propjiene (47), isobutjiene (47), acrylonitrile (48), acrolein (49), acrylates (50,47), aHyl ether (51), divinyl ether (52), maleates (53,54), vinyl chloride (55), diaHyl phthalate (56), and starch (graft copolymer) (47). 

Emulsion polymerizations of vinyl acetate in the presence of ethylene oxide- or propylene oxide-based surfactants and protective coUoids also are characterized by the formation of graft copolymers of vinyl acetate on these materials. This was also observed in mixed systems of hydroxyethyl cellulose and nonylphenol ethoxylates. The oxyethylene chain groups supply the specific site of transfer (111). The concentration of insoluble (grafted) polymer decreases with increase in surfactant ratio, and (max) is observed at an ethoxylation degree of 8 (112). 

Polymers ndResins. / fZ-Butyl peroxyneopentanoate and other peroxyesters of neopentanoic acid can be used as free-radical initiators for the polymeri2ation of vinyl chloride [75-01-4] (38) or of ethylene [74-85-1]. These peresters have also been used in the preparation of ethylene—vinyl acetate copolymers [24937-78-8] (39), modified polyester granules (40), graft polymers of arninoalkyl acrylates with vinyl chloride resins (41), and copolymers of A/-vinyl-pyrrohdinone [88-12-0] and vinyl acetate [108-05-4] (42). They can also be used as curing agents for unsaturated polyesters (43). 

Extension of the chlorosulfonation technology to base resins other than polyethylene, where value can be added, seems a logical next step. Polypropylene and ethylene copolymers containing additional functionaUty, ie, maleic anhydride graft, vinyl acetate, acrylic acid, etc, have been chlorinated and chlorosulfonated to broaden the appHcation base, particularly in coatings and adhesives (9,10). 

This chapter has so far dealt with the major fields of use of vinyl chloride polymers, namely plasticised PVC homopolymer, unplasticised PVC, including impact-modified grades, and copolymers particular based on vinyl acetate. There are, however, five particular special forms of vinyl chloride polymer which merit separate consideration, namely crystalline PVC, after-chlorinated PVC (often known as CPVC) and certain graft copolymers and two vinyl-chloride-based copolymers. 

As with poly(ethylene terephthalate) PBT-based copolymers have been introduced to overcome some of the deficiencies of the homopolymer. For example, the rather low notched impact strength of unreinforced grades has been overcome by partial replacement of the terephthalic acid with a longer chain aliphatic dicarboxylic acid. Improved toughness has also been obtained by grafting about 5% of ethylene and vinyl acetate onto the polyester backbone. 

Several authors have discussed the ion exchange potentials and membrane properties of grafted cellulose [135,136]. Radiation grafting of anionic and cationic monomers to impart ion exchange properties to polymer films and other structures is rather promising. Thus, grafting of acrylamide and acrylic acid onto polyethylene, polyethylene/ethylene vinyl acetate copolymer as a blend [98], and waste rubber powder [137,138], allows... 

It has been found that, for a fixed mineral filler content, the viscosity of PMF-based composites increases when the coat is made of polyethylene [164, 209, 293], poly(vinyl chloride) [316] and polypropylene [326, 327], The picture was different, however, for composites based on the ethylene/vinyl acetate copolymer to which kaolin with grafted poly (vinyl acetate) was added [336]. Addition of PMF with a minimum quantity of grafted polymer results in a sharp drop of flowability (rise of viscosity), in comparison to addition of unmodified filler but with a further increase of the quantity of grafted polymer the flow gradually increases and, depending on the kaolin content and quantity of grafted polymer, may even become higher than in specimens with unmodified filler, for equal concentrations. 

The synthesis of PDMS macromonomers with vinyl silane end-groups and their free-radical copolymerization with vinyl acetate, leading to poly(vinyl acetate)-PDMS graft copolymers, was described 346). The copolymers produced were later hydrolyzed to obtain poly(vinyl alcohol)-PDMS graft copolymers. 

II. B polyethylene glycol, ethylene oxide, polystyrene, diisocyanates (urethanes), polyvinylchloride, chloroprene, THF, diglycolide, dilac-tide, <5-valerolactone, substituted e-caprolactones, 4-vinyl anisole, styrene, methyl methacrylate, and vinyl acetate. In addition to these species, many copolymers have been prepared from oligomers of PCL. In particular, a variety of polyester-urethanes have been synthesized from hydroxy-terminated PCL, some of which have achieved commercial status (9). Graft copolymers with acrylic acid, acrylonitrile, and styrene have been prepared using PCL as the backbone polymer (60). 

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