Monomers for Adhesive Polymers, 5

Abstract

Summary: 2,4,6‐Trimethylphenyl 2‐[4‐(dihydroxyphosphoryl)‐2‐oxa‐butyl]acrylate (1) was synthesized by silylation of 2,4,6‐trimethylphenyl 2‐[4‐(dimethoxyphosphoryl)‐2‐oxa‐butyl]acrylate with trimethylsilyl bromide (TMSBr) and the hydrolysis of the silyl ester resulted in the formation of polymerizable phosphonic acid 1. The structure of this new monomer was characterized by IR, 1H, 13C and 31P NMR spectroscopy. The monomer dissolves well in ethyl acetate, ethanol or water and shows a high hydrolytic stability. 1 was homopolymerized with 2,2′‐azobisisobutyronitrile (AIBN), 2,2′‐azobis‐(2‐methylpropionamidine) dihydrochloride (AMPAHC) or dibenzoyl peroxide (DBPO) as the initiators. In a tetrahydrofuran (THF) solution, the deviations from the standard reaction kinetics were comparable with those of polymerizations of the other water soluble acrylate monomers. The unusual polymerization rate‐monomer concentration dependence with monomer intensity exponent less than 1 (m = 0.5) observed in THF solutions was even more declined from 1 in the polar medium EtOH‐H2O. The DBPO was a more effective polymerization initiator than AIBN. However, the overall activation energy of 81 kJ · mol−1 showed a usual temperature‐rate dependence observed in methacrylate ester polymerizations. In addition, monomer 1 was copolymerized with methyl methacrylate (MMA), ethyl 2‐[4‐(dihydroxyphosphoryl)‐2‐oxa‐butyl]acrylate (2), and N,N′‐diethyl‐1,3‐bis(acrylamido)propane (3), respectively, using THF as the solvent and AIBN as the initiator. The copolymerization curves revealed only slight deviations from the ideal copolymer‐feed composition. The estimated copolymerization parameters indicate a ready incorporation of comonomer units into polymer chains, preferably by alteration rather than at random.

Recent Developments of New Components for Dental Adhesives and Composites

“…Therefore, we synthesised the phosphonic acid monomer AEPA-4, which was completely stable under aqueous conditions at 42 8C during 4 months of investigation. [11][12][13][14] The improved hydrolytic stability of AEPA-4 in comparison to AEPA-1 is caused by the steric hindrance of hydrolysis regarding the methyl groups in the 2-and 6-position of the phenyl group. However, the bulky mesityl group also affects the reactivity of AEPA-4 in the free-radical polymerisation and AEPA-4 was therefore less reactive in the free-radical Figure 3.…”

“…copolymerisation with methyl methacrylate or AEPA-1. [14] Moreover, substitution of the ethyl group by the mesityl group also resulted in a corresponding decrease of solubility of the calcium phosphonate from 50 mg Á L À1 (calcium salt of AEPA-1) to 14 mg Á L À1 in the case of the calcium salt of AEPA-4. 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.…”

Monomers for Adhesive Polymers, 6

“…The hydrolytic stability of the synthesised monomers was investigated by means of 1 In order to test the etching effect of the monomers, freshly extracted bovine mandibular incisors were stored in the refrigerator for periods between two weeks and two months in de-ionised water. The teeth were embedded in unsaturated polyester resin (Castolite Buehler, Lake Bluff, USA) in cylindrical molds, ground with water-cooled P240-grit SiC followed by P1000-grit SiC abrasive paper to expose the buccal enamel or middle dentin.…”

“…[3] However, on this topic scientific papers are missing. In previous papers, we described the synthesis and radical polymerisation of an exceptionally hydrolytically stable Summary: 1,3-Bis(methacrylamido)propane-2-yl dihydrogen phosphate (1) was synthesised by phosphorylation of 1, 3-bis(methacrylamido)-2-hydroxypropane (2) with phosphorus oxychloride in tetrahydrofuran (THF) in the presence of triethylamine (TEA). The structure of the new monomer 1 was characterised by IR, 1 H NMR, 13 C NMR and 31 P NMR spectroscopies, elemental analysis and mass spectrometry.…”

Combination of nuclear magnetic resonance spectroscopy and nonlinear methods to analyze the copolymerization of phosphonic acid derivatives

“…This compound turned out to be one of the most important adhesive monomers. The kinetics of the copolymerization of ECPPA with other comonomers, for example, 2,4,6‐trimethylphenyl‐2‐[4‐(dihydroxyphosphoryl)‐2‐oxa‐butyl]acrylate in tetrahydrofuran (THF) has been reported . Copolymerization in THF at 65 °C initiated by azobisisobutyronitrile (AIBN) did not follow the ideal copolymerization kinetics as the copolymerization curves revealed slight deviations from the ideal copolymer‐feed composition.…”