ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Mechanical and thermal properties of terephthalic acid copolyesters of 4,4′-binaphthol-1,N monomer, and 2,2-bis(4-hydroxyphenyl)propane, A monomer (Bisphenol A), have been examined by differential scanning calorimetry (DSC) and dynamic mechanical methods. The copolyesters had different amounts and sequence distributions of diphenolic units. When the content of N units in the copolyesters was increased from 27 to 55 percent a significant increase of the dynamic Young's modulus, from 2485 to 4540 MPa at 110 Hz and room temperature, and an enhancement of the stress at yield, from 53.5 to 66.5 MPa, were observed. In the glass transition region of the copolyesters a smaller decrease in the value of E′ was noted compared with the homopolymers. For the copolyesters containing 55 percent of N units, the E′ decrease was only about 1.6 decades at 110 Hz within a range of temperatures of over 74 Kelvins. The DSC measurements of the copolyesters under consideration showed that the Tg depended only to a slight extent on their composition and structure and all Tg values were within the range of 494 ± 2 Kelvins, corresponding to that for poly [2,2-bis(4- hydroxyphenyl)propane terephthalate], the homopolymer of the A bisphenol monomer.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760211606
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