Zwitterionic chain polymerizations of cyanoacrylates

Abstract

The lecture reviews recent studies on vinyl and vinylidene compounds, chiefly alkyl cyanoacrylates. It emphasizes the kinetics, especially the distinctive SINT (slow‐initiation‐no‐termination) pattern, and the composite mechanism of initiation by tertiary amines. The need for corroboration of interpretations, clarification of ambiguities and extensions is emphasized.

Structural and adhesion properties of poly(ethyl 2-cyanoacrylate) post-cured at different temperatures and times

“…Table 1 shows that the T g value of pECN is somewhat similar regardless the polymer is post-cured or not (130 C for cured pECN at 25 C and 134-136 C for post-cured pECN at C); the T g values obtained in this study agree well with the ones previously reported for pECN [13]. On the other hand, the decomposition temperature increases and the decomposition enthalpy decreases for the post-cured pECNs, in greater extent by increasing the post-cure temperature, confirming higher extent of polymerization of pECN caused by a SINT mechanism [11]. TGA was used to assess the thermal stability and the structural changes in the cured and post-cured pECN.…”

“…On the other hand, the post-polymerization enthalpy of pECN cured at 25 C for 24 hours is 26 J/g and it is reduced noticeably (11 to 3 J/g) after post-cure (Table 1). Therefore, the post-cure of pECN at 45 C and, more markedly, at 90 C decreases the extent of post-polymerization of pECN, since the thermal treatments usually favored the termination step by a SINT (slow-initiated, nonterminated) mechanism in zwitterionic polymerizations initiated by tertiary amines [11].…”

“…On the other hand, depending on the initiator nature, the polymerization of cyanoacrylates can take place thought three different mechanisms: radical, anionic, and zwitterionic. Pepper [11] has proposed a SINT (slow-initiated, non-terminated) process for zwitterionic polymerizations using tertiary amines as initiators. Furthermore, based on kinetic studies, Johnston and Pepper [12] supported the absence of intrinsic termination process in the polymerization of cyanoacrylates.…”

Zwitterionic Nanofibers of Super-Glue for Transparent and Biocompatible Multi-Purpose Coatings

“…2c ). The polymerization reaction was terminated through the formation of the fibers, probably as a consequence of the complete evaporation of DMSO and of proton and hydroxide transfer from water molecules of the environment 22 25 27 28 .…”

Fast underwater bonding to polycarbonate using photoinitiated cyanoacrylate

“…Cyanoacrylates are among the most reactive monomers to be examined kinetically. Pepper and co-workers [18,19] studied their cure kinetics and the mechanism of polymerisation. Despite the fact that they employed carefully controlled experimental conditions, problems were experienced with respect to reproducibility.…”