NOVEL SUB-CEILING TEMPERATURE RAPID DEPOLYMERIZATION-REPOLYMERIZATIONREACTIONS OF CYANOACRYLATE POLYMERS

Dilute solutions of unimodal high-molecular-weight poly(butyl cyanoacr ylate) (''parent'' polymer) in tetrahydrofuran (THF) at 21 degrees C u nderwent rapid depolymerization accompanied by simultaneous repolymeri zation of the unzipped monomer to yield lower-molecular-weight ''daugh ter'' polymer following addition of tetrabutylammonium hydroxide (TBAO H), a slow initiator of butyl cyanoacrylate (BCA) monomer. The rate-de termining step for the reaction was tentatively identified as abstract ion of the terminal chain proton. Similarly, addition of TBAOH to a TH F solution of BCA monomer resulted in initial formation of high-molecu lar-weight (MW) polymer that subsequently rapidly depolymerized with s imultaneous formation of TBAOH initiated, low-MW daughter polymer. The depolymerization-repolymerization reaction is the relaxation process that occurs following perturbation of the monomer/high-MW parent polym er equilibrium by low-MW daughter polymer and proceeds at least 100 de grees C below the ceiling temperature of the parent polymer.