| 摘要 |
<p>Copolyamides contain (a) repeating units of formula (I) - Oc- -CONH(CH2)mNH- (I) and (b) repeating units of formula (II) -OC- -CONH(CH2)nNH-(II) where m amd n = 6-12. The amount of the amide units I and II is not 5 moles % of the total amide units. Pref. polyamides contain (i) 20-95 moles % of (I) and 80-5 moles % of (II), when m >= n, and (ii) 5-80 moles % of (I) and 95-20 moles % of (II), when m n. Small amounts of other copolymerisable components may be included. The copolyamides have melting points and melt viscosities which are low enough for moulding applications. They have a high degree of crystallinity, increased Young's modulus, improved dimensional stability and high tensile strength.</p> |
