Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2809-2816 
    ISSN: 0887-624X
    Keywords: 1,4-bis((3-hydroxypropylsulfonyl)butane ; polycarbonate ; poly(carbonatesulfone) ; liquid crystalline ; dipole-dipole interaction ; dielectric constant ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High molecular weight aliphatic poly(carbonate-sulfone) homopolymer (PC-343) and random copolymer (PC-343-10) were synthesized from 1,4-bis(3-hydroxypropylsulfonyl)butane (Diol-343) and a 1/1 molar mixture of Diol-343 and 1,10-decanediol, respectively. As a comparison, an aliphatic polycarbonate homopolymer (PC-10) was prepared from 1,10-decanediol. While PC-10 exhibited a single melting peak during its DSC heating scan, both PC-343 and PC-343-10 exhibited multiple reproducible first-order transitions during DSC heating scans. Both PC-343 and PC-343-10 showed broad reflections in their WAXD diagrams; the crystalline order of PC-343 is higher than that of PC-343-10. Based on the DSC and WAXD results and our discovery on the liquid crystalline behavior of aliphatic poly(carbonate-sulfone)s from 1,3-bis(hydroxypropylsulfonyl)propane, we suggest PC-343 and PC-343-10 are liquid crystalline and the liquid crystalline phase formation is directed by the dipole-dipole interactions between sulfone groups. Films were obtained from these polymers by compression molding and dielectric analyses were conducted on them. One glass transition related dielectric relaxation was observed in PC-343-10. One glass transition related dielectric relaxation and one sub-glass transition related dielectric relaxation were observed in PC-343. The glass transition temperature increases with the increase of sulfone content in the polymers. A dramatic rise in dielectric constant with temperature was observed in PC-343 and PC-343-10 at low frequencies, which is probably due to the sulfone dipole interaction with the electrical field. © 1994 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 32 (1994), S. 2291-2300 
    ISSN: 0887-624X
    Keywords: polycarbonate ; polysulfone ; liquid crystal ; 1,3-bis(3-hydroxypropyl sulfonyl) propane ; smectic ; X-ray ; dipole-dipole interaction ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aliphatic poly(carbonate-sulfone) homo- and copolymers were prepared from 1,3-bis(3-hydroxypropylsulfonyl)propane (Diol-333) and various alkanediols. The copolymers are random in nature since they were prepared by melt copolymerization. Both the homopolymer and the copolymers exhibited multiple reproducible first-order transitions during differential scanning calorimetry (DSC) heating scans, but most of them exhibited only single exotherm during cooling scans. Typical schlieren textures were observed when these polymers were cooled from their isotropic melts. The copolymers have wide-angle x-ray diffraction (WAXD) patterns almost identical to that of the homopolymer except in the low-angle spacing, indicating their packing in the crystalline domain in similar. DSC, cross-polarized optical microscopy, and WAXD revealed that these polymers were smectic liquid crystalline at room temperature. Since aliphatic poly(carbonate-sulfone)s are flexible linear polymers with no rigid rod components, the liquid crystalline phase formation is probably directed by the dipole-dipole interactions between sulfone groups in adjacent chains. © 1994 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...