Journal Article

Alkyl 2-cyano-2,4-pentadienoates and alkyl 2-cyano-2,4-hexadienoates were synthesized and characterized by spectroscopic methods. These were then evaluated as cross-linkers in 2-cyanoacrylate adhesive compositions to improve the heat stability of their adhesive bonds between various metal surfaces.

2-Allyl-3(5)-pentadecylphenols were synthesized and characterized spectroscopically; their acrylic and methacrylicesters were synthesized. The acrylicester was evaluated as a reactive monomer in u.v.-curable coating compositions and the methacrylicester in anaerobic adhesive formulations. Phenolic resin from 2-allyl-3(5)-pentadecylphenol was prepared and evaluated as a wood bonding adhesive.

The effect of adding various anhydrides, such as succinic, maleic, phthalic, and pyromellitic anhydrides, to alkyl cyanoacrylate on the heat ageing and moisture resistance properties of the adhesive bonds is studied. Such an addition was generally found to improve the adhesion of alkyl cyanoacrylate to metals, in addition to providing other improvements. Maleic anhydride is the only one that appears to act as a crosslinking agent with cyanoacrylate, thus providing improved heat and moisture-resistant bonds.

Various methacryloyloxymethylalkoxysilanes have been synthesized by nucleophilic substitution reactions starting from chloromethylalkoxysilanes under phase transfer catalysis conditions. The compounds thus obtained show an exceptionally high degree of reactivity with regard to hydrolysis and condensation both under acidic as well as under basic conditions compared to the established 3-methacryloyloxypropyltrimethoxysilane. A mechanistic model for this high reactivity by intramolecular activation is discussed.

Alicyclic mono and diacrylates from alpha-pinene and beta-pinene were synthesised and characterized spectroscopically. They were compounded in alkyl 2-cyanoacrylate adhesives as crosslinkers. Their effect on the adhesive bond strengths after exposing the adhesive bonds to various temperatures, was studied.

Adhesive properties of β-vinyl-α-cyanoacrylates and their anionic copolymerization with α-cyanoacrylates are studied. The ability of bifunctional β-vinyl-α-cyanoacrylates to enhance the thermal stability of cyanoacrylate adhesives is demonstrated.

Various alkyl2-bromoacrylates were synthesized in high purity and yield. They were characterized by spectroscopic techniques. The monomers were then formulated into aerobic adhesive compositions and their adhesive bond strengths between various surfaces were evaluated.

The photoinitiated polymerization of ethyl cyanoacrylate (ECA) by benzyl triphenylphosphonium hexafluoroantimonate (BP+) and (anthracen-9-ylmethyl)triphenylphosphonium hexafluoroantimonate (MAP+) was studied. Zwitterionic and free radical mechanisms which involved homolytic and heterolytic decomposition of the phosphonium salts are discussed. The anthracene-sensitized photopolymerization of ECA was also demonstrated.