| 摘要 |
The invention concerns a method for making polyamide. More particularly, the invention concerns a method for making polyamides derived from the reaction between a diacid and a diamine. It concerns a method for making a polyamide derived from the reaction of at least a diacid with at least a polyamide comprising the following steps: preparing a first mixture of diacid and diamine with a diacid/diamine molar ratio ranging between 0.8 and 0.995, preferably ranging between 0.95 and 0.99 in a first reactor (5); preparing a second mixture of diacid and diamine with a diacid/diamine molar ratio ranging between 1.005 and 1.2, preferably between 1.01 and 1.05, in a second reactor (4); introducing in melted form a first flow of the first mixture and a second flow of the second mixture in a stirred polymer reactor (7); drawing, preferably, continuously, from said reactor a flow of polyamide prepolymer; feeding said polyamide flow into a finishing step to obtain the desired degree of polymerisation. The invention is characterised in that the stoichiometry of the polyamide in the reactor (7) or the acid function/amine function ratios in the different reactors are measured by near infrared spectrometric analysis, and by controlling the feed flows in the different reactors using the results of said analyses. |
