Mechanism of alternating copolymerization of polar and hydrocarbon polymers

Abstract

Radical copolymerization of butyl methacrylate with 2,3‐dimethylbutadiene in the presence of Al(C2H5)2Cl or ZnCl2 results in alternating copolymers. The nature of active centers and the mechanism of polymerization in these systems have been studied by means of ESR measurements in combination with calorimetry at low temperatures. The active centers are monoradicals propagating by alternative addition of single monomer molecules; thus the reaction can be described in terms of a conventional kinetic scheme of radical additional polymerization. Participation of binary donor—acceptor complexes of the monomers in the reaction has not been confirmed. Similar conclusions have been drawn for the other alternating system studied, maleic anhydride–2,3‐dimethylbutadiene. The feasibility of formation of alternating copolymers in the studied systems by the conventional mechanism of binary radical copolymerization has been confirmed by qualitative quantum‐chemical treatment of the propagation reactions with due account to the donor–acceptor interactions in the transition state.

ESR Spectroscopy in Polymer Research

“…ESR studies of Lewis acids have been presented in several papers 753,787,788,939,940,945,1229,1354,2213,2517). The Lewis acids used as Friedel-Crafts catalysts are metal halides of Group III metals -most frequently the following: ZnC1 2 , CuCl 2 , Ale1 3 , BF 3 , GaCI 3 , SnCl 4 and SbCI 5 .…”

Use of Spin Trap Technique for Kinetic Investigation of Elementary Steps of RAFT-Polymerization

“…For instance, the application of the spin traps has helped to solve a number of problems in complexradical polymerization and copolymerization (Golubev et al, 1978). They have also helped to address controversies related to spontaneous initiation and unusual inhibition of some polymerization systems (Zaremski et al, 1999).…”

Hyperbranched macromolecules through donor‐acceptor type copolymerization of allyl–vinylene bifunctional monomers

“…Copolymerizations initiated by UV radiation, electrical current and radical initiators, have been described as cis ‐1.4 addition with charge transfer complex (CTC) participation 12. 13 Some of the other conjugated dienes which also copolymerize in 1:1 fashion with MA include 2,3‐dimethylbutadiene,14–16 2,3‐dichlorobutadiene, 1‐cyclohexyloxy‐1,3‐butadiene,17 2,3‐bis(diethylphosphonono)‐1,3‐butadiene,18 2,4‐hexadiene,19 1,3‐pentadienes,20, 21 1,1‐dichloropropyl‐1,3‐butadiene,22 1‐methoxy‐1,3‐butadiene,23 and cis ‐ and trans ‐1,3‐pentadiene 24…”