Molecular Weight Distribution of Hyperbranched Polymers Generated by Self-Condensing Vinyl Polymerization in Presence of a Multifunctional Initiator

Abstract

The molecular weight distribution (MWD) is derived for polymers generated by self-condensing vinyl polymerization (SCVP) of a monomer having a vinyl and an initiator group (“inimer”) in the presence of a multifunctional initiator. If the monomer is added slowly to the initiator solution (semi-batch process), this leads to hyperbranched polymers with a multifunctional core. If monomer and initiator are mixed simultaneously (batch process), even at vinyl group conversions as high as 99%, the total MWD consists of polymers which have grown via reactions between inimer molecules (i.e., the normal SCVP process) and those which have reacted with the initiator. Consequently, the weight distribution, w(M), is bimodal. However, the z-distribution, z(M), equivalent to the “GPC distribution”, w(log M) vs log M, is unimodal.

Role of cyclization in the synthesis of hyperbranched aliphatic polyesters

“…(10), DP n, app, c can be calculated correctly by Eq. (12). This can be verified in the scheme given in Fig.…”

“…From these two signals (b and c), the DP a, app, c was calculated using Eq. (10) and (12). Since the signal intensities are of crucial importance for the determination of the degree of cyclization n, the results are shown in Tab.…”

Monte Carlo Simulation of Hyperbranched Copolymerizations in the Presence of a Multifunctional Initiator

“…[14] For copolymerization, all possible reactions between the different structural patterns and active centers with double bonds are considered and shown in Scheme 1.…”

Synthesis of hyperbranched poly(tert-butyl acrylate) by self-condensing atom transfer radical polymerization of a macroinimer

“…The polydispersity index (PDI) is expected to be equal to the number-average degree of polymerization, P n , partially due to the inevitable presence of oligomers. Slow addition of the inimers to a multifunctional initiator will lead to higher DB and rather narrow MWD 14,15) . It has been also shown theoretically 16) and experimentally 8,16) that the self-condensing vinyl copolymerization (SCVCP) of AB* monomers with conventional monomers, M, leads to highly branched polymers, allowing for control of MWD and degree of branching.…”