Tough CA

An instant-setting adhesive composition comprising a 2-cyanoacrylate and at least one 1,1-disubstituted diene, the amount of said 1,1-disubstituted diene exceeding 50% by weight based on the total weight of both components. This composition is useful in the same fields as those where conventional 2-cyanoacrylate adhesives have been used, and is excellent in impact resistance, peel resistance, heat resistance and water resistance.

The condensation of active methylene compounds 1 with acetaldehyde was efficiently promoted by a catalytic amount of lithium bromide in the presence of acetic anhydride to give ethylidene malonates 2 in 77-97% yield.

An adhesive composition comprises (a) at least one polymerizable cyanoacrylate monomer, (b) 0.1 to 10% by weight of a polymerizable acrylate ester e.g. allyl methacrylate and (c) 0.1 to 20% by weight of a maleimide derivative of formula wherein R<7> and R<8> are from alkyl, cycloalkyl, aralkyl or arkaryl. The compositions may polymerize with ring-opening of the maleimide. They have excellent hot strength properties for long periods at 121 DEG C (250 DEG F) or more.

Cyanoacrylate adhesive compositions containing (a) a toughener (e.g., a core-shell copolymer such as an MBS, ABS, or MABS copolymer), the toughener optionally being treated to remove impurities which cause premature polymerization of cyanoacrylates, and (b) cyanoacrylate-compatible, toughener-compatible sustainer (e.g., an organic compound containing one or more unsubstituted or substituted aryl groups, such as diphenylmethane or dichlorobenzene). The inclusion of sustainer provides improved retention of toughness after heat aging of cured bonds of the adhesive.

Three different types of ion-supported TEMPO catalysts are synthesized and their catalytic activity in the chemoselective oxidation of alcohols is investigated. These new catalysts show high catalytic activity in water and can be reused for the next run by extraction of products. Recycling experiments exhibit that ion-supported TEMPO can be reused up to five times without loss of catalytic activity. This system offers a very clean, convenient, environmentally benign method for the selective oxidation of alcohols.

A xanthate derived photoinitiator, S-methacryloyl O-ethyl xanthate (MAX) bearing an electron-deficient polymerizable double bond has been found to be capable of distinguishing MMA and styrene, thereby dictating their polymerization pathways in distinctly different and controlled fashion. The structure, molecular weight, and the polydispersity of each polymer have been determined by spectral analysis and size-exclusion chromatography (SEC).