Awa na se ezali na bokeli ya PAPI .
PAPI (crude MDI) is produced in the same manner as MDI except that the ratio of the amount of aniline to hydrochloric acid is smaller. The synthesis of PAPI and MDI-like are carried out in two steps. First, the aniline and formaldehyde solution (formalin) is condensed into a polyamine mixture containing a certain amount of diamine under the action of a Lewis acid, and then the polyamine compound is subjected to phosgenation reaction to obtain PAPI. In the synthesis of polyamine compounds, the content of diamine is controlled to be about 50%. Generally, it can be achieved by adjusting the ratio of the amount of input of the two raw materials of aniline and formaldehyde, that is, the amount of the substance. It has been experimentally determined that when the molar ratio of aniline to formaldehyde is 1:75, pene na 50% ya diamine na kati ya composé polyamine synthétisé ezali{. Yango wana, rapport ya distribution ya groupe ya matière première, en général rapport ya quantité ya aniline na formaldehyde ezali 1.6 na 2. range ya O ebongwanaka, ba conditions ya fonctionnement mosusu pona polyamine{Point} ba oyo esengeli ya mdami ya mda ya mdami ya 6 6 oyo esengeli na oyo ya 6 6 6 oyo esengeli na ba oyo ya mda 6 oyo ba oyo ya mda 6 oyo ba 6 6 ba oyo ya 6 oyo esengeli na ba oyo ya 6 6 6 oyo ba sengeli na ba oyo ya 6 6 6 2019. Esengeli kozala composé ya polyamine oyo ezali na 60% tii na 75% ya diamine, mpe fungola ezwami mpe na kobongola rapport ya motango ya biloko ya aniline mpe ya formaldehyde oyo ezali na charge. Tango rapport ya motango ya substance aniline/formaldehyde ezali 4/1.4, composé synthétisé ezali na soki 75%. Mbala mingi, ndenge ya kosala co-production ya MDI na PAPI e adopter.