Alternating polyesteramides based on 1,4-butylene terephthalamide: 4. Alternating polyetheresteramides based on glycols (4NTglycol)

Polyetheresteramides (PEEAs) have been synthesised in the melt from 1,4-butylene terephthalamide and ethylene or propylene glycols. The ethylene glycols were ethylenediol, diethylene glycol, triethylene glycol and tetraethylene glycol. The propylene glycols were 1,3-propanediol and the mixtures of 1,2- and 1,3-propylenediols, 1,2/1,3-propanediol, dipropylene glycol and tripropylene glycol. The melting temperatures of the PEEAs decreased with increasing length of the glycols. The ethylene glycols have higher melting temperatures than the 1,2/1,3-propylene glycols. The undercooling for these polymers determined at 20 degrees C min(-1) was low (20-35 degrees C), suggesting a very high rate of crystallisation of the copolymers. Injection moulded samples were analysed with dynamic mechanical thermal analysis. The glass transition temperature for the ethylenediol polymer was 122 degrees C and the T-g decreased with increasing glycol length to 42 degrees C for the tetraethylene glycol. The T-g/T-m ratio for these polymers was high (0.69-0.70). The dimensional stability of these copolymers above the T-g was high. The diethylene glycol PEEA had a melting temperature of 262 degrees C, a glass transition temperature of 103 degrees C, a shear modulus at 150 degrees C of 180 MPa, an undercooling of 28 degrees C, a stress at break of 65 MPa and a modulus of 2.9 GPa. (C) 1998 Elsevier Science Ltd. All rights reserved.