The tacticity assignments from the literature for the 13C-NMR signals of the side-chain methylene group of poly(ethyl cyanoacrylate) are reversed, and new assignments of the main-chain methylene group are proposed. The assignments were made possible by a combination of DEPT and HETCOR NMR experiments on samples of varying microstructure distributions. The polymer tends toward syndiotacticity, not isotacticity as previously reported. The distribution of stereoisomers fits well to a Bernoulian statistical model.

Polycyanoacrylates were found to be inherently unstable. Even in the absence of a deliberately added strong base, their molecular weights decreased drastically on standing in solution in accord with observations by Ryan and McCann (Makromol Chem Rapid Commun 1996, 17, 217). The initial high molecular weight polymer disappeared over the course of a few hours in solution and was replaced by a much lower molecular weight material.

A fast-setting .alpha.-cyanoacrylate-type adhesive composition having good storage stability comprising an .alpha.-cyanoacrylate and about 0.1 ppm or more of at least one macrocyclic polyether compound or an analogue thereof, such as 18-crown-6 or 15-crown-5.

A process for bonding a polyolefin, polyfluoroolefin, polyethylene terephthalate, polyacetal, nylon or plasticizer-rich soft polyvinyl chloride substrate to a like substrate or for bonding a polyolefin, polyfluoroolefin, polyethylene terephthalate, polyacetal, nylon or plasticizer-rich soft polyvinyl chloride substrates to another substrate which comprises applying to the surface of at least one of the substrates to be bonded together an adhesion promoter composition comprising 0.001-10 wt.

A primer comprising an organometallic compound and an organic polymer, which is useful in bonding non-polar or highly crystalline resin substrates together or bonding said resin substrates and another material, such as a solid material, a coating material, paint or printing ink by using a 2-cyanoacrylate.

A sterile or non-sterile flavored monomeric adhesive composition includes a flavoring additive and a monomer. The composition can be applied, for example, to skin or the inside of the mouth. A method of making a sterile, flavored adhesive composition includes placing a mixture of a polymerizable adhesive monomer and a flavoring additive in a container, sealing the container, and sterilizing the mixture and the container. The flavored adhesive composition is particularly useful as a medical adhesive and can include 1,1 -disubstituted ethylene monomers, such as -cyanoacrylates.

The literature data on the application of organosilicon compounds as water scavengers in reactions of carbonyl com- pounds is surveyed. The reactions leading to both carbon–carbon (in particular, aldol-type condensations) and carbon–nitrogen bond formation, the synthesis of iminium salts by elimination reactions and heterocyclizations are considered.

An adhesive composition that contains cyanoacrylate monomers and cyclic or alkyl- or phenyl-terminated linear polydimethylsiloxane is particularly useful in applications requiring flexibility and elasticity. A method of removing, reducing or preventing scar tissue including applying an adhesive composition that contains cyanoacrylate monomer and cyclic or alkyl- or phenyl-terminated linear polydimethylsiloxane.

Die Synthese von purin-ähnlichen biheterocyclischen Ringsystemen wird beschrieben und insbesondere der Aufbau von verschieden substituierten Pyrazolo[3.4-d] pyrimidinen ausgehend von Pyrazolen oder Pyrimidinen besprochen. Synthesewege für Pyrazolo[3.4-c] pyridazine und Pyrazolo[3.4-b] pyridine ausgehend von Pyridazinen und Pyridinen und von Pyrazolo[3.4-b] pyrazinen und Pyrazolo[3.4-d] triazinen ausgehend von Pyrazolen werden angegeben. Als biheterocyclisches Ringsystem mit zwei kondensierten 6-Ringen werden die Pyrimido[4.5-d] pyrimidine erwähnt.