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Good Thermal (good + thermal)

Distribution by Scientific Domains
Polymers and Materials Science80%

Terms modified by Good Thermal

  • good thermal property
    		•
  • good thermal stability
    		•

    Selected Abstracts

    The Properties of Covalently Immobilized Trypsin on Soap-Free P(MMA-EA-AA) Latex Particles

    MACROMOLECULAR BIOSCIENCE, Issue 4 2005
    Kai Kang
    Abstract Summary: The covalent immobilization of trypsin onto poly[(methyl methacrylate)- co -(ethyl acrylate)- co -(acrylic acid)] latex particles, produced by a soap-free emulsion polymerization technique, was carried out using the carbodiimide method. The catalytic properties and kinetic parameters, as well as the stability of the immobilized enzyme were compared to those of the free enzyme. Results showed that the optimum temperature and pH for the immobilized trypsin in the hydrolysis of casein were 55,°C and 8.5, both of which were higher than that of the free form. It was found that Km (Michaelis constant) was 45.7 mg,·,ml,1 and Vmax (maximal reaction rate) was 793.0 ,g,·,min,1 for immobilized trypsin, compared to a Km of 30.0 mg,·,ml,1 and a Vmax of 5,467.5 ,g,·,min,1 for free trypsin. The immobilized trypsin exhibited much better thermal and chemical stabilities than its free counterpart and maintained over 63% of its initial activity after reusing ten times. TEM photograph of latex particles after trypsin immobilization. [source]

    Dehydrohalogenation in Alpha-Functionalized Poly- p -xylylenes,

    CHEMICAL VAPOR DEPOSITION, Issue 4 2006
    P. Carrow
    Abstract Poly(p -xylylene) or parylene has been around for more than a half a century. It is typically deposited by the Gorham method from [2.2] paracyclophane. However, another method is via alpha-derivatives of p -xylene. Both poly(,-bromo- p -xylylene) and poly(,-chloro- p -xylylene) have been successfully deposited by this route through predominately HBr or HCl dehydrohalogenation gas-phase reactions. In the study reported here we synthesize ,,,,,-tribromo- p -xylene and ,-bromo-,,,,,-dichloro- p -xylene as CVD precursors to yield ,,,- and ,,,,-dihalogenated poly(p -xylylene)s to try to convert them, via post-deposition annealing, to poly(phenylene ethynylene) (PPE). PPE and its intermediate poly(phenylene vinylene) (PPV), have potentially better thermal and oxidative properties, and in addition they are both photoluminescent. The as-deposited and annealed thin films have been characterized by Rutherford backscattering spectrometry (RBS), infrared spectroscopy, and UV-vis spectrophotometry, and electrically tested by dielectric constant, bias-temperature stress (BTS), and leakage current. It is found that the thin films crystallizes concurrent with the formation of PPV and possibly converts to PPE but has much residual chlorine and bromine. However, PPV exhibits excellent stability in contact with copper and is more thermally stable than poly(p -xylylene). [source]

    Fabrication of Regularly Patterned Microporous Films by Self-Organization of an Amphiphilic Liquid-Crystalline Diblock Copolymer in a Dry Environment

    MACROMOLECULAR MATERIALS & ENGINEERING, Issue 1 2010
    Dong Chen
    Abstract An amphiphilic LCBC PEO -b- PAz consisting of flexible PEO as a hydrophilic block and poly(methacrylic acid) containing an azobenzene moiety in side chain as a hydrophobic LC segment was synthesized and used to fabricated microporous films by spin-coating method under a dry environment. With the help of a small amount of water, well-arranged ellipsoidal micropores embedded in a LC matrix were obtained and the pore size is in the range of several tens µm of water. The influence of water content and rotational speed was studied in detail. It was found that regularly patterned microporous films can be prepared with certain water content, and the pore size can be easily tailored through changing the rotational speed. The obtained microporous structures showed good thermal and photo stability. [source]

    Low Water Swelling and High Proton Conducting Sulfonated Poly(arylene ether) with Pendant Sulfoalkyl Groups for Proton Exchange Membranes

    MACROMOLECULAR RAPID COMMUNICATIONS, Issue 24 2007
    Jinhui Pang
    Abstract Novel side-chain-type sulfonated poly(arylene ether) with pendant sulfoalkyl group copolymers (PSA-SPAE-6F) have been synthesized by direct copolymerization from a new sulfonated monomer, sodium 3-(4-(2,6-difluorobenzoyl)phenyl)propane-1-sulfonate. The sulfonate content could be easily controlled by adjusting the sulfonated and the unsulfonated monomer feed ratio. The obtained copolymers all show good thermal and mechanical properties. It should be noted that the most highly sulfonated copolymer, PSA-SPAE-6F90 with an ion exchange capacity of 1.30 mequiv,·,g,1, shows a proton conductivity of 0.11 S,·,cm,1 and a water swelling ratio of only 12.9% at 100,°C, which indicates its high proton conductivity and excellent dimensional stability in hot water. [source]

    Coloured inorganic-organic films on glass

    PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2007
    K. Cholewa-Kowalska
    Abstract Two kinds of inorganic-organic hybrid materials (A and B class) were obtained in the form of thin films on glass. As starting materials were used: PhTES + TEOS (A class); PhTES + GPTMS + TBA (B class). Hybrid materials were coloured using ORASOL type dyes. The coloured coatings were put on glass by dip-coating technique. The structure of hybrid matrix was examined by spectroscopic methods: FTIR, 29Si MAS NMR, 27Al MAS NMR. On this base structural units of hybrid were identified. UV/VIS spectra of thin films were measured directly after obtainment as well as after thermal and chemical treatment of samples. It has been found that UV/VIS spectra originate from electron transitions between ligands and transition metal ions. The coloured centres in hybrid matrix show good thermal and chemical resistance. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]