Ketones copolymers

SN2 reactions of primary organolithium compounds on PMMA in dilute homogeneous solution may be considered as a model system where all the important reaction parameters may be controlled they allow both a quantitative analysis of PMMA chain reactivity and the synthesis of well defined ketonic copolymers within a wide range of possible structural variations. The two homologous series of organolithium compounds and the corresponding reaction conditions we selected are given below ... 

SN, reactions of primary stabilized organolithium compounds on polyalkylmethacrylates affords a very versatile synthetic route to model ketonic copolymers substitution is selective and quantitative up to DSm of 0.60,and it is easily monitored by the initial... 

In the sulfonated poly(arylene) systems described so far, the sulfonic acid groups have been statistically distributed along the polymer main chain. Poly(arylenes) in which the sulfonic acid sites are separated from the main chain by means of a spacer group have also been developed. Examples of systems in which this has been attempted include poly(p-phenylenes) (17),i isr poly(p-phenylene)-poly(aryl ether ketone) copolymers (18), and polyimides (19,20). These are shown in Eigure 3.24. 

Prior to imide formation, the imide-aryl ether ketimine copolymers were converted to the imide-aryl ether ketone analogue by hydrolysis of the ketimine moiety with para-toluene sulfonic acid hydrate (PTS) according to a literature procedure [51,52,57-59]. The copolymers were dissolved in NMP and heated to 50 °C and subjected to excess PTS for 8 h. The reaction mixtures were isolated in excess water and then rinsed with methanol and dried in a vacuum oven to afford the amic ester-aryl ether ether ketone copolymer, 2e (Scheme 8.)... 

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

Figure 1. Irradiation of PS-vinyl aliphatic ketone copolymers in N2 at...

The results of these experiments are summarized in Table V, which shows values of A0/A and Z for the ketone copolymer films. All of the polymers in the first section underwent significant damage and were very brittle. However, there was not much attenuation in the first section as indicated by the similar Z values of the PS-MIPK films placed at the beginning and the end of the section. It should be pointed out that the errors in determination of Mn by GPC are substantial — considerably greater than the FTIR measurements. Nevertheless, the Z values correlate quite well with A0/A, indicating the importance of the Norrish type I process in causing chain scission. 

Heskins, M., Reid, W. J., Pinchin, D. J., Guillet, J. E., "Photodegradation of Vinyl Chloride - Vinyl Ketone Copolymer, " Chapter 19 UV-Light Induced Reactions in Polymers, S. S. Labana, Ed., No. 50, ACS Symposium Series, 1976. 

Furfural-ketone copolymers have found commercial use, particularly in the Soviet Union, in applications ranging from floor coverings, anti-corrosion coatings, wood adhesives, and binders for carbon/graphite. When an alkaline catalyst is used, furfural is known to react with acetone to form the so-called furfurylidene acetone monomer, a mixture of 2-furfurylidene methylketone (6), bis(2-furfurylidene) ketone (7), mesityl oxide, and other oligomers. 

The relationship between structure and photoinitiation activity has been examined for polymeric systems bearing side-chain 1-substituted cyclohexyl-phenyl ketone moieties in the UV curing of the HDDA/BA equimolar mixture [19,20]. Indeed, the activity of poly[(l-acryloxycyclohexyl)phenyl ketone] [poly (APK)] and styrene/4-chloromethyl-styrene/l-(4-styrylmethyloxy)cyclohexyl phenyl ketone copolymers (PABOK) has been compared with that of the corresponding low-molecular-weight structural models such as 1-hydroxy-cyclohexyl phenyl ketone (HPK), 1-acetoxy-cyclohexyl phenyl ketone (ACPK) and l-(4-isopropyl-benzyloxy) cyclohexyl phenyl ketone (PIBOK). 

Photode radation of Vinyl Chloride-Vinyl Ketone Copolymer... 

Preliminary experiments showed that when thermally stabilized thin films (80 p thickness) of vinyl chloride-methyl vinyl ketone copolymers were subject to UV radiation they became brittle without color formation. When the ketone concentration in the ci olymer was approximately 6 mol-%, the time to brittleness in the Accelerometer was less than 20 hr, whereas 40 to 50 hr were required if the ketone concentration was only 2%. Samples of PVC homcpolymer, identically stabilized, were photolyzed along with the copolymers. No color or chemical change was apparent in these samples, even after 100 hr photolysis. 

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%. 

Figure 6. Photolysis of 4 1 blends of polystyrene with polystyrene 5% vinyl ketone copolymers...

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