ISSN:0258-0322    

DOI:10.1002/masy.19860040102

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractOrgano‐element polymers are a rapidly developing field of high molecular weight compounds. As A.N. Nesmeyanov points out, the organo‐element polymer chemistry is the science lying between inorganic and organic chemistry, that is undoubtedly its positive factor, because this allows to prepare polymeric compounds combining positive properties of the compounds of these two fields. Due to this, many elements of the Periodic System capable of forming various polymeric compounds are widely investigated, and a number of organo‐element polymers have already found practical application in many fields of modern engineering and national economy. It should be noted that at present already more than 75 elements have been used in synthesis of various high molecular weight organo‐element compounds. Besides carbon, among these compounds hydrogen, oxygen and silicon are remarkable. Other elements only begin their way to the polymer field. The concept of raznozvennost (different‐units structure) is of great importance for studying the synthesis and the properties of these polymers. This concept made it possible to clarify distinguishing role of anomalous units in determining the complex of physico‐chemical properties of high molecular weight organo‐element compounds. It is especially important to emphasize that among factors giving rise to anomalous units causing polymer raznozvennost the presence of stable isotope atoms arranged statistically in polymer macromolecules plays an essential role. The lecture is a general review of polymers by the groups of the Periodic System. It discusses the methods for synthesis of organo‐element polymers used at the present time as well as perspective development of this fiel

ISSN:0258-0322    

DOI:10.1002/masy.19860040103

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0258-0322    

DOI:10.1002/masy.19860040104

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0258-0322    

DOI:10.1002/masy.19860040105

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractMethyl methacrylate, benzyl methacrylate, butyl methacrylate, and methacrylic acid can be polymerized by 1, 2, 2‐tetraphenyl‐1, 2‐diphenoxyethane (TPPA), 1, 1, 2, 2‐tetraphenyl‐1, 2‐bis‐(trimethylsiloxy) ethane (TPSA), and 1, 1, 2, 2‐tetraphenyl‐1, 2‐dicyanoethane (TPCA) (1–3). The polymerization with these initiators is characterized by three steps; in the first period oligomers from MMA and initiator radicals are formed by primar

ISSN:0258-0322    

DOI:10.1002/masy.19860040106

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0258-0322    

DOI:10.1002/masy.19860040107

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractThe electrical conductivity of aromatic and heteroaromatic polymers as well as polymers with aromatic, heteroaromatic and vinylene units in the main chain, can be enhanced by oxidation. In a single electron transfer reaction, a polymer with a salt structure (“doped polymer”) can be formed. Such polymers can also be prepared in a one‐step reaction from low‐molecular weight compounds by oxidants, as well as by electrochemical reaction. Electrochemically produced samples have higher electrical conductivities (as high as 6298K = 0,5 Ω−1· cm−1) than samples made by chemical oxidation from the same star

ISSN:0258-0322    

DOI:10.1002/masy.19860040108

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0258-0322    

DOI:10.1002/masy.19860040109

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

ISSN:0258-0322    

DOI:10.1002/masy.19860040110

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY

摘要:

AbstractFlexible linear polysiloxanes with inorganic backbones such as poly(diethylsiloxane) and poly‐(dipropylsiloxane) contain no traditional mesogenic groups neither in the main chain nor in side chains and, nevertheless, they are able to form thermotropic mesophases. Recent developments in the study of thermodynamics, kinetics, structure and morphology of these mesophase polymers are considered. The temperature interval of existence of the mesophase is strongly dependent on the length of side radicals and molecular weight. These dependences are examined in detail. X‐ray structure and the optical textures seen in the polarizing microscope are discussed. It is shown that large mesophase lamellae represent a very characteristic feature of the morphology of poly(diethylsiloxane). The linear growth rate of the lamellae and the overall calorimetric kinetics of the mesophase formation have been studied at various temperatures and the results obtained have been analyzed using the Avrami equation and the kinetic theory of the linear growth. As a result of the kinetic analysis two‐dimensional growth has been suggested in accordance with the microscopic observation. The formation of the mesophase in slightly crosslinked poly(diethylsiloxane) samples can be initiated by stretching. The stress‐strain and thermomechanic (deformation calorimetry data) behaviour of such samples is briefly di

ISSN:0258-0322    

DOI:10.1002/masy.19860040111

出版商:Hüthig&Wepf Verlag    

年代:1986

数据来源: WILEY