MALDI-TOF CHARACTERIZATION AND CROSS-LINKING STUDY OF SOME NOVEL POLYCYCLIC CARBONATES

Attempts were made to synthesize polycyclic carbonates by reacting C-C ortho-coupled 4-t-butylphenol resins with excess triphosgene under hi gh-dilution conditions. Under these conditions complete functionalizat ion of the phenolic groups was not possible because of steric hindranc e. Novolac-type phenol-formaldehyde resins were selected for this stud y because there is less steric hindrance in these systems toward the f ormation of the cyclic carbonates. The MALDI-TOF MS technique plays a crucial role in the detection of the absolute masses of the different oligomeric polycyclic carbonates formed. The functionalization of the hydroxy groups by formation of cyclic carbonates has also been confirm ed by MMR. Our objective in the synthesis of these types of polycyclic carbonates was to obtain thermosetting materials with a high cross-li nk density. When mixed with a commercial BPA polycarbonate (M-w = 3300 0) transesterification reactions take place resulting in a cross-linke d system. The polycyclic carbonates were mixed with the linear polycar bonate in different proportions and cured at different temperatures by using lithium stearate as catalyst. Curing a mixture which contained 10 wt% of the polycyclic carbonates at 350 degrees C for 30 min result ed in a highly cross-linked system.