摘要:

The photochemistry of small molecules has been studied in great detail for many years [1]. Yet the effect of UV light on very large molecules which contain the same basic chromophores was treated rather empirically for a long time until the subject became one of fundamental importance. Naturally, the study of photosynthesis and related processes, the irradiation of proteins and nucleic acids, and the development of synthetic polymers, which are often exposed to the sun's radiation in common usage, have created much practical and theoretical concern in this area. The wealth of information that had been accumulated for small molecules provided a convenient starting point for the consideration of the photochemical properties of “large” molecules. However, a unique situation obtains when chromophores are held on a polymer chain so that straightforward extrapolation could not be justified before extensive studies were carried out on the general photochemistry of typical macromolecular systems.

ISSN:1532-1797    

DOI:10.1080/15321797508080008

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Poly-as-triazines are high temperature thermoplastics which exhibit excellent potential for use as multipurpose functional and structural resins. These materials evolved from work during the last 15 years which was directed toward the development of new improved polymers for use primarily in high-performance, high-temperature environments. Potential applications in the functional area include use as sealants, coatings, films, membranes, and foams, while in the structural area these polymers are useful as adhesives and composite matrices. The as-triazine polymers, particularly the polyphenyl-as-triazines, exhibit a favorable combination of price, processability, and performance which places them as leading candidates for use in high performance high temperature applications. The purpose of this discussion is to summarize the chemistry and mechanical properties of as-triazine polymers.

ISSN:1532-1797    

DOI:10.1080/15321797508080009

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

For the past 20 years there has been an active program of research among polymer chemists seeking to prepare thermally stable materials for use as fibers, films, rubbers, adhesives, and other plastic uses. Many types of polymeric molecules have been investigated and the search is still going on. There are, of course, many degrees of thermal stability to be considered. For this report I intend to deal with the polymers which are stable in the range of 300°C and above. This limits the number of materials to be covered to what one can include in a limited survey of the field such as this paper is designed to be.

ISSN:1532-1797    

DOI:10.1080/15321797508080010

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

The concept that maleic anhydride cannot be homopolymerized is so widely accepted that it is cited in most textbooks on polymer science as an illustration of the steric hindrance imposed by 1,2-disubstitution of the double bond. However, in recent years it has been demonstrated that maleic anhydride readily undergoes polymerization under gamma and UV radiation as well as in the presence of free radical catalysts and various organic bases. In some cases the polymer contains cyclopentanone groups, resulting from decarboxylation, or unsaturated ketone groups, resulting from ring opening, in addition to the anhydride groups. Further interesting developments include the proposed participation of excited maleic anhydride in the polymerization process and of poly(maleic anhydride) in the grafting of maleic anhydride on various polymeric substrates.

ISSN:1532-1797    

DOI:10.1080/15321797508080011

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

Sorption of gases or vapors by polymers was studied as early as the 1930s [1]. However, it was not until the 1960s that there was considerable publication of such results in the literature. The early interest in vapor sorption by polymers stemmed perhaps from the observation that polymer/solvent solutions were highly nonideal by comparison with ideal solutions of lower molecular-weight substances. However, as synthetic polymers, particularly rubbers, became of increasing commercial and strategic importance during World War II, vapor sorption studies took on added significance. After World War II, synthetic polymers other than elastomers began to be made in quantity, the pace accelerating ever more rapidly in the 1960s and 1970s.

ISSN:1532-1797    

DOI:10.1080/15321797508080012

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:1532-1797    

DOI:10.1080/15321797508080007

出版商:Taylor & Francis Group    

年代:1975

数据来源: Taylor