摘要:

AbstractThe solid‐state polymerization ofN‐vinylcarbazole initiated by UV‐radiation at 25, 32.5, and 45°C was studied. The rate of polymerization increased with increase in temperature. The limiting conversion at all temperatures is 56%. The molecular weight, determined by viscosity measurements, first increased, reached a maximum, then decreased. The molecular weight distribution, studied by GPC, was broad with a shoulder on the low molecular weight side. The morphology of partially polymerized single crystals was studied by electron scanning microscopy to determine the propagation mode of polymerization with respect to the monomer structure. The high activation energy of 71‐9kJ/mol and ESR spectrum suggest a radical mechanism of polyme

ISSN:0007-1641    

DOI:10.1002/pi.4980210112

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractA method is proposed for the determination of low levels of moisture in rubbers and other soluble polymers. The material for analysis is dissolved in an appropriate solvent and triethylaluminium is added to react with the water contained in the sample. The liberated ethane is analysed by a simple GC technique. The method is calibrated using an internal standard and by addition of known amounts of water. A series of natural and synthetic rubbers dried under varying conditions were found to have water contents in the range 0.01‐2% w/w. Removal of proteinaceous material from natural rubber reduces the equilibrium water content of the stored rubber. Active hydrogen impurities in the rubbers are shown to interfere with the determination and consequently the observed water content must be assumed to represent the upper limit of water unless such impurities are known to be absent, or present only in negligible amount

ISSN:0007-1641    

DOI:10.1002/pi.4980210113

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

摘要:

AbstractThe formation of a 1:1 polymer‐polymer complex from poly(acrylic acid) and poly(vinyl methyl ether) has been detected by viscosity measurements in aqueous solution, and the glass transition temperature of the isolated complex has been determined. Infrared spectroscopy indicates that specific hydrogen bonding occurs between the components of the complex. Miscible blends of the two polymers can also be formed (at all compositions) and, although hydrogen bonding occurs, the structures of the blends are likely to be dissimilar to that of the comple

ISSN:0007-1641    

DOI:10.1002/pi.4980210114

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980210117

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980210119

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980210123

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980210124

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY

ISSN:0007-1641    

DOI:10.1002/pi.4980210101

出版商:John Wiley&Sons, Ltd    

年代:1989

数据来源: WILEY