Novel acrylic macromonomer with amphiphilic character derived from Triton X‐100: Radical copolymerization with methyl methacrylate and thermal properties

Abstract

This article explores the synthesis of a novel methacrylic macromonomer with an amphiphilic character derived from poly(ethylene glycol) tert-octylphenyl ether (MT) and its respective homopolymer. To know their reactivity in radical copolymerization reactions with methyl methacrylate (MMA), a model monomer (MTm) was synthesized to determine the reactivity ratios and compare them with the low molar fractions of copolymers of MT with MMA because they were difficult to isolate. They were r MTm ϭ 0.97 and r MMA ϭ 0.95. The compositional diagrams when representing the weight fraction of MT and MTm in the feed and the copolymer suggested that a clear correlation exists between the experimental points of the model monomer MTm and the macromonomer MT ones, suggesting that the length of the side poly(ethylene oxide) chain does not affect the reactivity of the methacrylic double bond in the prepared monomers for this type of polymerization reaction. The reactivity ratios of the copolymers have a tendency for the formation of random or Bernoullian copolymers. The glass-transition temperatures (T g 's) of the prepared copolymers were determined by differential scanning calorimetry, deviated from the Fox equation, and discussed on the basis of treatments that consider the influence of the monomeric units along the copolymer chains, determining the T g of the corresponding alternating dyads.

Radical copolymerization studies of an amphiphilic macromonomer derived from Triton X-100. Reactivity ratios determination by in situ quantitative 1H NMR monitoring

“…In this case r AA Z0.31, indicating a relative higher reactivity of the macromonomer in the copolymerization reaction. The former result differs, as expected, from that reported in a previous paper in which copolymerisation reaction between MT and MMA was studied [2].…”

“…In fact, model monomers for the end group can provide a useful first approximation to the reactivity of a given macromonomer. We previously reported [2] an estimation of the reactivity of macromonomer MT in copolymerization with hydrophobic monomer MMA by using the model monomer MTm which posses just one ethylene oxide side unit in its chemical structure (Fig. 1).…”

“…The methacrylic derivative of Triton X-100, macromonomer MT, and the model monomer MTm were synthesized as described before [2] and were used immediately after their synthesis. AA (Fluka) was distilled and freshly used (bpZ141 8C).…”

“…In such cases, macromonomer reactivity can be estimated by different approaches. In a previous paper [2], we described the copolymerisation behaviour of a new amphiphilic macromonomer derived from Triton X-100 with hydrophobic methyl methacrylic MMA monomer. Macromonomer reactivity was estimated by means of an appropriate low molecular weight model monomer.…”

“…The interest on the synthesis and characterization of large amphiphiles, such as macromonomers [1][2][3] or random, star, graft and block copolymers [1,3,4], has considerably increased in the last decades. Large amphiphiles are very flexible in attaining a great variety of micro-assemblies due to the wide range of different copolymer architectures, and show a lower critical micelle concentration and slower exchange kinetics.…”