Weatherable semicrystalline polyesters based on 1,4 cyclohexanedimethanol, 1,4-cyclohexanedicarboxylic acid (CHDA) or dimethyl 1,4-cyclohexane dicarboxylate (DMCD) can be prepared under normal melt-phase conditions, using titanium tetrabutoxide as catalyst.The effect of monomer ratio, reaction temperature and catalyst loading on the final polymer properties was studied. Under the proper polymerization conditions, poly(1,4 cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate) polymers with high molecular weight can be obtained. During polymerization, isomerization can occur towards the thermodynamically stable cis-trans ratio of 34–66 mol%. Carboxylic acid end groups can catalyze the isomerization and therefore the polymerization is more critical starting from CHDA rather than DMCD. Moreover, temperature control becomes a key factor to avoid or to limit isomerization. The study of the isomerization of the different monomers permitted a better understanding of the isomerization and therefore of the polymerization process.
Poly(1,4-cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate): analysis of parameters affecting polymerization and cis–trans isomerization / M. Colonna; C. Berti; E. Binassi; A. Celli; M. Fiorini; P. Marchese; M. Messori; D. J. Brunelle. - In: POLYMER INTERNATIONAL. - ISSN 0959-8103. - STAMPA. - 60:(2011), pp. 1607-1613. [10.1002/pi.3128]
Poly(1,4-cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate): analysis of parameters affecting polymerization and cis–trans isomerization
COLONNA, MARTINO;BERTI, CORRADO;CELLI, ANNAMARIA;FIORINI, MAURIZIO;MARCHESE, PAOLA;
2011
Abstract
Weatherable semicrystalline polyesters based on 1,4 cyclohexanedimethanol, 1,4-cyclohexanedicarboxylic acid (CHDA) or dimethyl 1,4-cyclohexane dicarboxylate (DMCD) can be prepared under normal melt-phase conditions, using titanium tetrabutoxide as catalyst.The effect of monomer ratio, reaction temperature and catalyst loading on the final polymer properties was studied. Under the proper polymerization conditions, poly(1,4 cyclohexylenedimethylene-1,4-cyclohexanedicarboxylate) polymers with high molecular weight can be obtained. During polymerization, isomerization can occur towards the thermodynamically stable cis-trans ratio of 34–66 mol%. Carboxylic acid end groups can catalyze the isomerization and therefore the polymerization is more critical starting from CHDA rather than DMCD. Moreover, temperature control becomes a key factor to avoid or to limit isomerization. The study of the isomerization of the different monomers permitted a better understanding of the isomerization and therefore of the polymerization process.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.