5-lactone base composition

Alternative sheet flooring materials prepared from the poly(lac-tide) based composites have been described (1). The polymeric material can include 30-50% of PVC, polyfethylene glycol) (PEG), poly(glycoUde), ethylene vinyl acetate, polycarbonate, poly(capro-lactone) (PCL), poly(/S-hydroxyalkanoate)s, or ionomer modified polyolefins. 

Our constitutional scheme is based on different kinds of information. The first type of information comes from an analytical study of milled spruce wood lignin prepared according to Bjorkman (3). The analytical data considered comprise the elemental composition of lignin, its content of methoxyl groups and other ether bonds, the types and amount of its different hydroxyl groups, carbonyl, and lactone groups, and the kind and number of its biphenylyl linkages and other bonds in which the benzene nucleus is involved. The work that led to data of this kind has been carried out in various laboratories and has been described previously (9,11). 

Liquid composite molding techniques, making use of the ring opening polymerization of various cyclic mono- and oligomers, wUl remain hot topics . Apart from CBT, cyclic lactones and lactams will be favored as matrix precursors. Gong et at [76] demonstrated the feasibihty of this method by producing PA-6 based SPC via infiltration of PA-6 fiber assembly with e-caprolactam followed by in situ polymerization of the latter. 

Intramolecular [80] and intermolecular [81,82] trapping of acylpalladium intermediates with enolates has been studied. Intermolecular versions can involve trapping with both C- and 0-enolates. The Pd-catalyzed carbonylation reactions of alkenyl iodides in the presence of various ketone enolate precursors displayed an interesting dichotomy the expected 0-enolate trapping product 47 may undergo cyclization to give six-membered lactone 48, and the product s composition critically depends on the amount of a base and the structure of ketones (Scheme 9.19). 

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