The N-sodiocaprolactam-catalysed anionic polymerisation of e-caprolactam is activated by e-caprolactone which itself acts as a comonomer, yielding copolyesteramides. At lower temperatures and lower catalyst concentrations, copolymerisation of the lactone is favoured over that of lactam; higher tempe
Copolyesteramides—III. Anionic copolymers of ε-caprolactam with ε-caprolactone. Crystalline character and mechanical properties
✍ Scribed by I. Goodman; R.N. Vachon
- Publisher
- Elsevier Science
- Year
- 1984
- Tongue
- English
- Weight
- 705 KB
- Volume
- 20
- Category
- Article
- ISSN
- 0014-3057
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✦ Synopsis
Almtraet--The crystalline character of anionic copolymers of c-caprolactam with ~-caprolactone and of some alternatingly-sequenced analogues has been studied and investigations made of the mechanical and dynamic mechanical properties of the anionic copolymers. The anionic copolymers are crystalline over the whole range of compositions. Depending on the proportions of NH(CH2)sCO and O(CH2)5CO units and the thermal history of the copolymers, the crystalline phases present are either wholly of polyamide type or composed of co-existing and mutually incompatible polyamide and polyester entities. However, the constituents appear to be miscible in the amorphous phase. The mechanical properties of the copolymers (like their crystalline melting temperatures) change discontinuously with composition, showing minima in the values of initial modulus, yield stress and breaking stress at ca 25-40% amide-group content where dual crystallinity exists. In addition to their variation with composition, the properties are also affected by changes in the procedure of anionic copolymerisation.
📜 SIMILAR VOLUMES
The chain structures of copolyesteramides formed by anionic ring-opening copolymerisation of e-caprolactam with e-caprolactone have been investigated. The copolymers are shown to possess random multiblock structures with chains composed of O(CH2)sCO[NH(CH2)sCO]. groups (having relatively small value
Copolymers of c-CL/L-LA and c-CLIDL-LA and for comparison homopolymers PLLA, PDLLA, and PCL were allowed to age in a buffer solution of pH 7 a t 23 and 37°C and studied for the changes in the mechanical properties taking place as a function of hydrolysis time. Tensile modulus measurements showed the
## Abstract Anionic polymerization of ϵ‐caprolactam was initiated with the potassium salt of ϵ‐caprolactam and accelerated with phenyl isocyanate, toluylene diisocyanate, 4,4′‐diphenylmethane diisocyanate, some derivatives of these isocyanates (urethanes, ureas, and allophanates), or combinations o