Styrene vinyl ketone copolymers

Table I. Properties of Styrene-Vinyl Ketone Copolymers...

Recently it has been shown (36) that electron-beam irradiation of styrene-vinyl ketone copolymers show higher yields of type-I radicals than expected from UV photolysis measurements. It seems clear that some part of the excess energy of high-energy photons and electrons is imparted to the translation kinetic energy... 

Since the x-ray absorbance A is likely to be identical for the styrene copolymer films used in this experiment, Z will be proportional to the quantum yield when the films are exposed to equal intensities / of radiation. Representative values (31) for the carbonyl loss and molecular-weight change for three styrene-vinyl ketone copolymers are summarized in Table 12. It is clear fiom the carbonyl-loss data that the relative sensitivity of these films to synchrotron radiation is the same as for UV exposure. This has important implications for the design of photoresists for soft x-ray patterning. 

Blends. The type I reaction produces free radicals which, in the presence of oxygen, initiates photooxidation which also results in a decrease in the polymer molecular wei t. An indication of the relative importance of the type I reaction in these systems can be estimated from the amount of chain scission induced in a blend of the copolymers with homopolymer polystyrene. For these experiments, one part of 5% vinyl ketone copolymer was blended with four parts of styrene homopolymer to retain an overall ketone monomer concentration of 1%. 

As shown in Table 11, the photoreduction process is quite efficient in phenyl vinyl ketone copolymers with styrene. Because of the rapid intersystem crossing in the phenyl ketone chromophore, it seems likely that both the reduction and chain scission processes proceed via the intermediacy of the triplet state. 

The Norrish type II reaction of vinyl ketone copolymers also leads to scission of the backbone of polymer chain. Typical temperature dependence of the quantum yield for chain scission due to the Norrish type II reaction is shown in Fig. 27 for the copolymer of styrene and phenyl vinyl ketone There is a relatively small ittcrease in the quantum yield below T owing to the presence of local mode rdaxation in the main chain, but a drastic increase tak place in the region of glass transition temperature. Above T the quantum yield for the type II process is identical to that observed in solution. 

Shvinskas, J.A. and Guillet, J.E., y-Radiolysis of ketone polymers. II. y-Irradiation of styrene-methyl vinyl ketone copolymers, /. Polym. Sd. Polym. Chem. Ed., 11, 3057, 1973. 

Other patents include copolymers of vinyl ketones with acrylates, methacrylates, and styrene (53) an ethylene—carbon monoxide (1—7 wt %) blend... 

Copolymers of acrylonitrile and methyl acrylate and terpolymers of acrylonitrile, styrene, and methyl methacrylate are used as bamer polymers. Acrylonitrile copolymers and multipolymers containing butyl acrylate, ethyl aciylate, 2-ethylhexyl acrylate, hydroxyethyl acrylate, methyl methaciylate. vinyl acetate, vinyl ethers, and vinylidene chlonde are also used in bamer films, laminates, and coatings. Environmentally degradable polymers useful in packaging are prepared from polymerization of acrylonitrile with styrene and methyl vinyl ketone. 

If one wishes to prepare a positive photoresist it is important to obtain polymers vdiich undergo efficient chain scission in the solid phase. Recently we reported studies on a series of copolymers of styrene with a variety of ketone functional groups which were introduced by copolymerization with substituted vinyl ketone monomers. The copolymer structures are shown schematically in Table V. Two processes are responsible for the reduction in molecular weight in these polymers when irradiated with either UV light or electron beams. These are shown schematically below. 

In this report we examine the effects of several vinyl ketone monomers on the photodegradation of polystyrene in the solid phase. Previous work Sj has indicated that copolymers containing vinyl ketones undergo photolysis by the Norrish type I and type n primary reactions. Studies by Golemba and Gulllet and by Kato and Yone-shiga 0 have shown that these processes also occur in copolymers of styrene with meUiyl vinyl ketone and widi phenyl vinyl ketone. 

It is important to point out that the quantum yield for the Norrish II chain scission reaction ( Cs) is highly affected by the mobility of polymer chains. For example, the photolysis CS for a film of the copolymer poly(styrene-co-phenyl vinyl ketone) irradiated at 313 nm in the solid state was shown to be low (0.04—0.09) at temperatures below the copolymer Tg (glass transition temperature) but increased dramatically at,... 

The radical copolymerization of cyclic ketene acetal with various vinyl monomers such as styrene, MMA, vinyl acetate, and methyl vinyl ketone could afford the copolymers with ester groups in the main chain (26-28). These copolymers showed enzymatic degradability and photodegradability and are applicable as environmentally degradable materials. 

Other studies on ketone containing polymers include copolymers of unsaturated ketones with styrene and methyl methacrylate and poly(methylisoprenyl ketones) for use as photoresists. A review has appeared on the laser flash photolysis of vinyl ketones. ... 

Further confirmation of the important effect of solid-phase transitions in polymer photochemistry was reported by Dan and Guillet (29). They studied the quantum yields of chain scission, c >s, as a function of temperature in thin solid films of vinyl ketone homo- and copolymers. For polymers where the Norrish type-II mechanism was possibici large increases in n were observed at and above the glass transition T. Figure 8 shows this effect in a styrene copolymer containing about 5% phenyl vinyl ketone (PVK). Below Tg, )s is about 0.07, but at Tg it rises to about 0.3, a value similar to that observed for photolysis in solution at 2S°C. A similar effect was observed with poly (methyl methacrylate-co-methylvinyl ketone) (PMMA-MVK) and PVK homopolymer. 

Extensive studies have been reported on copolymers of styrene with a variety of ketone functional groups introduced by copolymerization with substituted vinyl ketone monomers. The copolymer structures are shown schematically in Table 8. 

The problem is apparently due to some residual aluminum that is hard to remove. If, however, the reduction is carried out in a iV-methylmorpholine solution, followed by addition of potassium tartrate, a pure product can be isolated. A -Methylmorpholine is a good solvent for reductions of various macromolecules with metal hydrides.In addition, the solvent permits the use of strong NaOH solutions to hydrolyze the addition complexes that form. Other polymers that can be reduced in it are those bearing nitrile, amide, imide, lactam, and oxime pendant groups. Reduction of polymethacrylonitrile, however, yields a product with only 70% of primary amine groups. Complete reductions of pendant carbonyl groups with LiAlH4 in solvents other than A -methyl-morpholine, however, were reported. Thus, a copolymer of methyl vinyl ketone with styrene was fully reduced in tetrahydrofuran. ... 

EVK. See Ethyl vinyl ketone EVM. See Ethylene/VA copolymer EVOH EVOH copolymer. See Ethylene/vinyl alcohol copolymer Evoprene G 940. See Styrene-ethylene/butylene-styrene block copolymer EW-POL 7902 NaC 12. See Sodium laurate EW-POL 9110. See Ammonium oleate EX 1035, EX 1044, EX 1057. See Polyethylene, low-density... 

Polyarylate resin Polyarylether ketone resin Polyester carbonate resin Polyetherimide resin Polyethylene, chlorinated Polyethylene glycol Polyethylene, medium density Poly (p-methylstyrene) Poly (p-methylstyrene), rubber-modified Poly (oxy-1,2-ethanediyloxycarbonyl-2,6-naphthalenediylcarbonyl) resin Poly (oxy-p-phenylenesulfonyl-p-phenyleneoxy-p-phenyleneisopropylidene-p-phenylene) resin Poly (phenyleneterephthalamide) resin Polysulfone resin Poly (tetramethylene terephthalate) Polyvinylidene chloride Potassium sorbate Potato (Solanum tuberosum) starch Silica, colloidal Silicone Sodium N-alkylbenzenesulfonate Sodium bicarbonate Sodium tetraborate pentahydrate Starch, pregelatinized Styrene/acrylates copolymer Styrene/butadiene polymer Styrene/DVB copolymer , 1,1 -Sulfonylbis (4-chlorobenzene) polymer with 4,4 -(1-methylethylidene) bis (phenol) and 4,4 -sulfonylbis (phenol) Synthetic wax Tapioca starch Tetrafluoroethylene/perfluoro (propyl vinyl ether) copolymer Tocopherol Triglycidyl isocyanurate VA/crotonates copolymer Vinyl chloride/ethylene copolymer Wheat (Triticum vulgare) starch... 

It has been shown by Angier and Watson [A8, W2] that if an elastomer is swollen with a vinyl monomer (styrene, chlorostyrene, acrylic acid, methyl acrylate, methacrylic acid, methyl methacrylate, vinyl pyridine, methyl vinyl ketone, etc.), mastication in the absence of oxygen can lead to the formation of block copolymers. This would seem to occur through the mechanism... 

Complete reductions of pendant carbonyl groups with LiAlH4 in solvents other than N-methylmorpholine, however, were reported. Thus, a copolymer of methyl vinyl ketone with styrene was fully reduced in tetrahydrofuran [242]. 

The foUowing activity coefficients and interaction parameters determined by GLC for solute-statistical copolymers may be found in the literature (a) forty three non-polar and polar solutes on ethylene-vinyl acetate copolymer with 29% weight of vinyl acetate at 150.6 and 160.5°C [105] chloroform, carbon tetrachloride, butyl alcohol, butyl chloride, cyclohexanol, cyclohexane, phenol, chlorobenzene and pentanone-2 on the same copolymer with 18% weight vinyl acetate at 135°0 [102], normal xdkanes (C5, Oj, Og, Ojo), oct-l-ene, chlorinated derivatives, n-butanol, toluene, benzene, methyl-propyl-ketone and n-butyl-cyclohexane on the copolymer mentioned with 40% weight vinyl acetate at 65, 75 and 85°0 [68, 106] (b) n-nonane, benzene, chloroform, methyl-ethyl-ketone and ethanol in methyl methacrylate-butyl methacrylate copolymer with 10% butyl methacrylate [32] (c) hydrocarbons in styrene-alkyl methacrylates copolymers at 140°C [101] (d) the solutes in (b) on butadiene-acrylonitrile copolymer with 34% weight acrylonitrile [68]. 

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