Swelling behavior and thermal stability of poly(methylmethacrylate) crosslinked by the oxozirconium cluster Zr₄O₂(methacrylate)₁₂

Abstract

A new isomer of the oxozirconium cluster Zr 4 O 2 (methacrylate) 12 was obtained by reaction of zirconium butoxide with an excess of methacrylic acid. Contrary to the known isomer, the structure is centrosymmetric with a planar, rhombic Zr 4 core. Copolymerization with a 56-207-fold excess of methylmethacrylate results in cluster-crosslinked poly(methylmethacrylate) that swells in ethyl acetate but does not dissolve. The solvent uptake during swelling decreases and the thermal stability improves with an increasing portion of the cluster.

Zirconium-methacrylate oxoclusters as new hybrid materials for the modification of epoxy systems

“…Similar profile was reported by Trimmel et al [21] for the degradation of Zr 4 O 2 (OMc) 12 , confirming the presence of the ZrMe oxocluster. The weight loss between 200 and 600°C corresponds to around 34 wt% of methyl methacrylate moiety, which is in agreement with that result reported by Trimmel et al [21].…”

“…The TGA curve presents two well-defined degradation steps: the first one in the temperature range 100-200°C may be ascribed to the degradation of physically adsorbed methacrylic acid, as also suggested by Trimmel et al [21]. The second step in the range of 200-600°C is attributed to the complete decomposition of the methacrylate complex [9,21]. Similar profile was reported by Trimmel et al [21] for the degradation of Zr 4 O 2 (OMc) 12 , confirming the presence of the ZrMe oxocluster.…”

“…Zirconium-methacrylate oxocluster (ZrMe) used in this work was synthesized according to the procedure described in the literature [21]. In a typical procedure, 0.05 mol of zirconium n-propoxide in a 70 % solution in n-propanol was mixed with 0.35 mol of methacrylic acid under nitrogen atmosphere.…”

Highly Dispersed Mixed Zirconia and Hafnia Nanoparticles in a Silica Matrix: First Example of a ZrO2–HfO2–SiO2 Ternary Oxide System

“…The photoinitiator Irgacure 184 (I184, 1-hydroxycyclohexyl-1-phenylketone) was received as a gift by Ciba Specialty Chemicals, Basel, Switzerland. The M 4 O 2 (OMc) 12 clusters were synthesized starting from the corresponding alkoxides by a previously reported procedure [39,40].…”

“…These clusters are synthesized by the reaction of metal alkoxides with methacrylic acid, as reported elsewhere. [39,40] The methacrylate moieties of the cluster and that of the silane are copolymerized, while the alkoxy groups of the silane undergo hydrolysis and condensation reactions to form a silica network. These and similar metal oxoclusters have been already used as inorganic building blocks for the synthesis of a wide variety of inorganic-organic hybrid materials.…”