investigation of thermal behavior of bulk-aminolyzed pla with pamam

Thermal behavior of poly(lactic) acid (pla) bulk-modified through aminolysis with poly(amidoamine) dendritic polymer (pamam) was investigated. two methods were utilized to prepared films from bulk-aminolyzed pla powder: (1) solution (b-4h-film) and (2) compression molding (b-4h-m) methods. fourier-transform infrared spectroscopy (ftir) analysis, differential scanning calorimetry measurements (dsc), and thermogravimetric analysis (tga) of neat and bulk aminolyzed-pla were conducted. ftir results confirmed a presence of new peak at 1650 cm-1 corresponding to –nh bending vibration, and separate double peak between 3705-3110 cm-1 associated to stretching vibration of –nh amide groups which can be attributed to the absorption of amide carbonyl groups of pamam. dsc results proved an influence of pamam presence on reduction of glass transition temperature. in addition, a decrease in cold-crystallization temperature and an increase in endothermic melting enthalpy for both b-4h-film and b-4h-cm indicated that pamam acted as a nucleation agent.  tga and dtg results showed that bulk-aminolysis accelerated thermal decomposition in which the changes for films prepared through compression was more evident. all in all, thermal behavior of bulk aminolyzed pla changed significantly upon the proposed modification and film preparation method due to enhanced crystallization.