| 摘要 |
<p>A process for increasing the molecular weight of a polyamide in the presence of alumina-containing titanium dioxide, said process comprising heating a polyamide containing terminal carboxy and amino groups, and alumina-containing titanium dioxide, in the presence of a catalytically effective quantity of at least one phosphonic acid catalyst and/or ester thereof selected from: R(CH2)nPO3R12 wherein: R is 2-pyridyl or 2-methoxyphenyl; each R1 is independently selected from H or C¿1-10? alkyl; and n is 0 or an integer of from 2-5 with the proviso that n is 0 when R is 2-methoxyphenyl.</p> |
