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We developed a copolymeric bioadhesive system with the potential to be used as a tissue adhesive based on biopolymer dextran. Copolymeric hydrogels comprising a urethane dextran (Dex-U) and 2-hydroxyethyl methacrylate (HEMA) were prepared and crosslinked under the ultraviolet (UV) irradiation. In this study, the photopolymerization process was monitored by real time infrared spectroscopy (RTIR). The adhesion strength was evaluated by lap-shear-test. The surface tension, viscosity of the solutions and the cytotoxicity assays were investigated. Compared to Dex-U system, the addition of HEMA remarkably improved the properties of Dex-H system especially the adhesion strength and the nontoxicity. And materials variation could be tailored to match the need of tissues. The copolymeric tissue adhesives demonstrated promising adhesion strength and nontoxicity. The maximum adhesion strength reached to 4.33±0.47 Mpa which was 86 times higher than that of Tisseel. The obtained products have the potential to serve as tissue adhesive in the future., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Polymethyl methacrylate (PMMA) is an important thermoplastic polymer and a versatile lithographic resist. However, the low heat resistance and low dry-etch resistance seriously restricts the application of PMMA in high-end devices and advanced nanolithography. Herein, methyl methacrylate (MMA) was copolymerized with two comonomers 1-adamantyl methacrylate (AdMA) and 1-acryloyloxy-3-hydroxyadamantane (HAdMA), and a series of copolymers P(AdMA-co-MMA) and P(HAdMA-co-MMA) with different contents of HAdMA were prepared. The UV–Vis, ellipsometer, DSC, TG, and TG–MS techniques were employed to investigate the effects of adamantyl and hydroxyadamantyl substituents on the optical and thermal properties of PMMA. The introduced hydroxyadamantyl not only significantly enhanced the refractive index, but also maintained the high transparency and low dispersion of PMMA. The glass transition temperature and thermal stability of PMMA were also greatly improved by the hydroxyadamantyl. The initial decomposition temperature of PMMA increased from 160 to about 260 ℃ after introducing 5% HAdMA. HAdMA was more effective than AdMA in improving the optical and thermal properties of PMMA. The novel P(HAdMA-co-MMA) copolymer has overcome the shortcomings of traditional PMMA and is anticipated to significantly broaden its range of applications. [ABSTRACT FROM AUTHOR]

Polymethyl methacrylate (PMMA) is a widely used optical polymer due to its excellent transparency and durability. However, the sole methyl group shows pure PMMA low refractive index and low UV absorbility, and poor thermal stability. In this work, two comonomers phenyl methacrylate (PhMA) and adamantyl methacrylate (AdMA) were used for copolymerization with methyl methacrylate (MMA), and three copolymers P(AdMA-co-MMA), P(PhMA-co-MMA) and P(AdMA-co-PhMA-co-MMA) were prepared. They were characterised by FTIR, 1H NMR, UV-Vis, ellipsometer, DSC, TG, and TG-MS, and the effects of phenyl and adamantyl substituents on the optical and thermal properties of PMMA were studied. It was found that phenyl played an important role in increasing the absorption and refraction of PMMA in the deep UV region (190–260 nm), while the glass transition temperature and thermal stability of PMMA were more affected by adamantyl than by phenyl. Introduction of phenyl and adamantyl substituents provided a method to tune the optical and thermal properties of PMMA as photoresist or antireflective coating for deep UV lithography. [Display omitted] [ABSTRACT FROM AUTHOR]