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Fluoroalkyl methacrylates, 2,2,2‐trifluoroethyl methacrylate (1), hexafluoroisopropyl methacrylate (2), 1,1,1,3,3,3‐hexafluoro‐2‐methyl‐2‐propyl methacrylate (3), and perfluoro t‐butyl methacrylate (4) were synthesized. Homopolymers and copolymers of these fluoroalkyl methacrylates with methyl methacrylate (MMA) were prepared and characterized. With the exception of the copolymers of MMA and 2,2,2‐trifluoroethyl methacrylate (1), the glass transition temperatures (Tgs) of the copolymers were found to deviate positively from the Gordon‐Taylor equation. The positive deviation from the Gordon‐Taylor equation could be accounted for by the dipole–dipole intrachain interaction between the methyl ester group and the fluoroalkyl ester group of the monomer units. These Tg values of the copolymers were found to fit with the Schneider equation. The fitting parameters in the Schneider equation were calculated, and R2 values, the coefficients of determination, were almost 1.0. The refractive indices of the copolymers, measured at 532, 633, and 839 nm wavelengths, were lower than that of PMMA and showed a linear relationship with monomer composition in the copolymers. 2 and MMA have a tendency to polymerize in an alternating uniform monomer composition, resulting in less light scattering. This result suggests that the copolymer prepared with an equal molar ratio of 2 and MMA may have useful properties with applications in optical devices. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4748–4755, 2008

Biodegradable polymeric materials are intensively used in biomedical applications. Of particular interest for drug-delivery applications are polymers that are stable at pH 7.4, that is, in the blood stream, but rapidly hydrolyze under acidic conditions, such as those encountered in the endo/lysosome or the tumor microenvironment. However, an increase in the acidic-degradation rate of acid-labile groups goes hand in hand with higher instability of the polymer at pH 7.4 or during storage, thus posing an intrinsic limitation on fast degradation under acidic conditions. Herein, we report that a combination of acid-labile dimethyldioxolane side chains and hydroxyethyl side chains leads to acid-degradable thermoresponsive polymers that are quickly hydrolyzed under slightly acidic conditions but stable at pH 7.4 or during storage. We ascribe these properties to high hydration of the hydroxy-containing collapsed polymer globules in conjunction with autocatalytic acceleration of the hydrolysis reactions by the hydroxy groups.

Biodegradable polymeric materials are intensively used in biomedical applications.Ofparticular interest for drugdelivery applications are polymers that are stable at pH 7.4, that is,inthe blood stream, but rapidly hydrolyze under acidic conditions,such as those encountered in the endo/lysosome or the tumor microenvironment. However,a ni ncrease in the acidic-degradation rate of acid-labile groups goes hand in hand with higher instability of the polymer at pH 7.4 or during storage,thus posing an intrinsic limitation on fast degradation under acidic conditions.Herein, we report that ac ombination of acid-labile dimethyldioxolane side chains and hydroxyethyl side chains leads to acid-degradable thermoresponsive polymers that are quickly hydrolyzed under slightly acidic conditions but stable at pH 7.4 or during storage.W eascribe these properties to high hydration of the hydroxy-containing collapsed polymer globules in conjunction with autocatalytic acceleration of the hydrolysis reactions by the hydroxy groups.

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