CA Preparations

Allyl methacrylate, AMA was polymerized in CCl4 solution by α,α′‐azoisobutyronitrile at 50°C. The thermal degradation mechanism of PAMA was characterized by MS, TGA‐FT‐IR and FT‐IR‐ATR methods. The mass spectrum and TGA thermogram showed two stage degradation. The first stage of degradation was mostly linkage type degradation for the fragmentation of pendant allyl groups at 225–350°C. In the second stage, at 395–515°C, the degradation is random scission and depolymerization types. This was also supported by direct thermal pyrolysis of polymer under vacuum.

The adhesive bond of allyl 2-cyanoacrylate between steel substrates has been analyzed and compared to that of ethyl 2-cyanoacrylate. Mechanical strength as well as thermomechanical, calorimetric, thermogravimetric, and dynamic mechanical response was observed. It was demonstrated that the allyl 2-cyanoacrylate bonds exhibit improved temperature resistance owing to the formation of heat-induced crosslinks in the adhesive layer, resulting in much improved lap-shear strengths.

Crosslinked polymers which are produced from monomers containing glycerol carbonate groups, crosslinking monomers and, where appropriate, other monoethylenically unsaturated monomers are composed of principally spherical porous particles and are very suitable as carrier materials for the immobilization of biologically active substances.

The invention relates to a method for producing glycerol carbonate methacrylate in the presence of metal-chelate catalysts of the metal ion-1,3-diketonate type.

The synthesis of t-butyldimethylsilyl cyanoacetate and the reactions of its anion with acyl donors are described. The reagent was found to be the method of choice for the syntheses of α-cyano ketone substrate analogues for carboxypeptidase A. These compounds have been shown to be potent mechanism-based inactivators for the enzyme.

The ring-opening polymerization (ROP) of trimethylene carbonate (TMC) initiated by water or n-pentanol and catalyzed by trifluoromethanesulfonic acid (HOTf) or methanesulfonic acid (MSA) has been investigated. In contrast with HOTf, MSA was found to afford poly(trimethylene carbonate) (PTMC) free of ether linkages even under forcing conditions. The comparison of the two acids substantiates further that activity does not simply correlate with acidity.

An effective protocol has been developed that allows the smooth protodecarboxylation of diversely functionalized aromatic carboxylic acids within 5−15 min. In the presence of at most 5 mol % of an inexpensive catalyst generated in situ from copper(I) oxide and 1,10-phenanthroline, even nonactivated benzoates were converted in high yields and with great preparative ease.

A catalyst generated in situ from palladium acetate and tricyclohexylphosphine efficiently catalyzes the reduction of carboxylic acids with sodium hypophosphite in the presence of pivalic anhydride to give aldehydes with high selectivity. The low cost and convenient handling of the reagents makes this process a valuable alternative to hydrogenations and metal hydride reductions.

The invention relates to new industrial products of the general formula ##STR1## a process for the manufacture of these products and their application in hydrometallurgy.