Grafting of polyesters from ultrafine inorganic particles: Copolymerization of epoxides with cyclic acid anhydrides initiated by COOK groups introduced onto the surface

Abstract

The grafting of polyesters onto ultrafine inorganic particles, such as silica, titanium oxide, and ferrite, by use of potassium carboxylate (COOK) groups introduced onto the surface was investigated. The introduction of COOK groups onto the surface was achieved by the neutralization of acid anhydride groups, which were introduced by the reaction of 4‐trimethoxysilyltetra‐hydrophthalic anhydride with hydroxy groups on the surface: the amount of COOK groups introduced onto the surface of silica, titanium oxide, and ferrite was estimated to be 1.92, 0.94, and 0.62 mmol/g, respectively. It was found that the anionic ring‐opening copolymerization of epoxides with cyclic acid anhydrides is initiated by COOK groups introduced onto the surface. In the polymerization, polyester formed was effectively grafted onto the surface based on the propagation of the polymer from COOK groups on the surface: the percentage of grafting of polyester from chloromethyloxirane and phthalic anhydride onto silica, titanium oxide, and ferrite reached to 118.3, 82.1, and 7.5%, respectively. The rate of the polymerization and percentage of grafting increased with an increase in COOK group content of the ultrafine particles. The grafting of polyester onto these particles was confirmed by infrared spectroscopy. Polyester‐grafted ultrafine particles produced a stable colloidal dispersion in organic solvent.

Cationic Graft Polymerization from Ultrafine Silica Initiated by Acylium Perchlorate Groups Introduced onto the Surface

“…We also reported that potassium carboxylate groups introduced onto ultrafine particles have ability to initiate the anionic ring-opening alternating polymerization of epoxides with cyclic acid anhydrides and the corresponding polymer, i.e., polyester, was grafted onto these surfaces. 5 Furthermore, lithium silanolate groups introduced onto silica surface were capable of initiating anionic graft polymerization of methyl methacrylate and cyclic siloxanes. 6 Cationic graft polymerization of polymers onto ultrafine silica has never been reported.…”

Branched Polymer-Grafted Silica. Cationic Postgrafting from Pendant Acylium Perchlorate Groups of Grafted Polymer Chains on Ultrafine Silica Surface

“…5 Polymer-grafted silica (1.0 g) was dispersed in 100 cm 3 of tetrahydrofuran with a magnetic stirrer, and the dispersion was allowed to stand at room temperature. After a prescribed time, 5.0 cm 3 of dispersion liquid was taken out with a pipet, dried in vacuo, and the residual silica particles were weighed.…”

“…1 • 2 In a series of papers, we reported the grafting of polymers onto these ultrafine particles initiated by surface azo, 3 peroxide,4 potassium carboxylate, 5 and acylium perchlorate 6 groups. During these polymerizations, polymer-grafted ultrafine particles with a higher percentage of grafting were successfully obtained through the propagation of polymer chains from the particle surface.…”

Curing of Epoxy Resin by Hyperbranched Poly(amidoamine)-grafted Silica Nanoparticles and Their Properties

“…[1][2][3][4][5] We have reported the surface initiated graft polymerization of various monomers onto silica nanoparticle by using previously introduced initiating groups on the surface, such as azo 6 and peroxyester, 7 acylium perchlorate, 8 and potassium carboxylate. 9 In addition, we have reported that hyperbranched poly-(amidoamine) (PAMAM) can be grown from amino groups on silica nanoparticles, 10 chitosan powder, 11 and carbon black 12 surfaces using dendrimer synthesis methodology ( Figure 1). Grafting was achieved by repeating the following two processes in methanol [10][11][12] and in solvent-free dry-system: 13 (1) Michael addition of amino groups on the surface to methyl acrylate (MA), and (2) amidation of the resulting terminal methyl ester groups with ethylenediamine (EDA).…”