Synthesis and modeling of new phosphorus‐containing acrylates

Abstract

New methacrylate monomers containing phosphonic acid or both phosphonic and carboxylic acids were synthesized through the reaction of t-butyl a-bromomethyl acrylate with triethyl phosphite followed by the selective hydrolysis of the phosphonate or t-butyl ester groups with trimethylsilyl bromide and trifluoroacetic acid. The copolymerization of these monomers with 2-hydroxyethylmethacrylate was investigated with photodifferential scanning calorimetry at 40 8C with 2,2 0 -dimethoxy-2-phenyl acetophenone as a photoinitiator. Quantum mechanical tools were also used to understand the mechanistic behavior of the polymerization reactions of these synthesized monomers. The propagation and chain-transfer reactions were considered and rationalized. A strong effect of the monomer structure on the rate of polymerization was observed. The polymerization reactivities of the monomers increased with decreasing steric hindrance and/or increasing hydrogen-bonding capacity because of the hydrolysis of the phosphonate and the t-butyl ester groups.

Recent Developments of New Components for Dental Adhesives and Composites

“…In this context, it should be mentioned that highly phosphonated double hydrophilic block copolymers based on poly(ethylene glycol) and poly(AEPA-1) blocks can control the morphology of calcium carbonate from smooth spherical structures to porous structures even at a rather low polymer concentration due to the strong effect of the phosphonate groups on the crystallisation of the mineral. [15] A number of acrylate phosphonic acids APA-1 to APA-3 ( Figure 4) were reported by Avcy et al [16,17] Unfortunately, the free-radical bulk polymerisation of phosphorus-containing acrylate monomer APA-1 was unsuccessful. [16] This was also observed with other vinyl phosphorus monomers.…”

“…It was explained by steric effects in the propagation reaction [18] and was confirmed by quantum mechanical calculations in the case of APA-2. [17] In contrast, homopolymers with a number-average molecular weight of 11 400 g Á mol À1 were formed by the free-radical polymerisation of APA-3 in the presence of 2,2 0 -azoisobutyronitrile (AIBN) after 24 h. Furthermore, methacrylates (MA) of hydroxyl alkyl phosphonates have been mentioned in the context with dental materials, for example, 2-(methacryloyloxy)-ethylphosphonic acid (MAPA-1) [19] or the difunctional monomer MAPA-2 ( Figure 5). [20] However, these monomers are not hydrolytically stable, because they undergo hydrolysis if water is present, and form methacrylic acid.…”

Polyglycidol-based metal adhesion promoters

“…1 13 31.0 (ArCH 2 CH 2 ), 31.6 (ArCH 2 ), 60.9, (d, 2 1 13 31.0 (ArCH 2 CH 2 ), 31.6 (ArCH 2 ), 60.9, (d, 2 …”

“…31 ). 1 H NMR (DMSO-d 6 ): signals were the same as reported for (V PE ), only differing in the relative intensity.…”

“…26 Others have also reported the chemoselective dealkylation of phosphonate esters in the presence of carboxylic acid esters; 15,18,31 however, these reports all focus on low molecular weight acrylates with only one phosphonic acid group per molecule. Previously, we have demonstrated the transformation of PG bound diethylphosphonatoethyl groups to phosphonic acids by using TMS-Br.…”