Melt Grafting of N-Carbamyl Maleamic Acid onto Linear Low-Density Polyethylene

ANDRÉS E. CIOLINO; MARCELO D. FAILLA; ENRIQUE M. VALLÉS

JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY

JOHN WILEY & SONS INC

Lugar: New York; Año: 2002 vol. 40 p. 3950 - 3958

0887-624X

The grafting of N-carbamyl maleamic acid (NCMA) onto linear low-densitypolyethylene (LLDPE) was carried out with different concentrations of 2,5-dimethyl-2,5-di(tert-butylperoxy) hexane (DBPH) as an initiator. The modification process wasperformed in the molten state with a Brabender mixer. All the materials were characterizedwith Fourier transform infrared (FTIR) spectroscopy, differential scanningcalorimetry, and melt rheology. The analysis of the FTIR spectra indicated that thegrafting efficiency increased with the concentration of both NCMA and DBPH. Thecalorimetric experiments showed that the modification process did not noticeably alterthe enthalpy of fusion of LLDPE, whereas the melting temperature of the modifiedpolymers was slightly lower than that corresponding to the original LLDPE. Therheological response of the molten polymers, determined under dynamic shear flow atsmall-amplitude oscillations, indicated that the modification process induced crosslinkingof the chains. Both the dynamic viscosity and elastic modulus of the modifiedLLDPE increased with the concentration of NCMA and DBPH, showing that largermolecules were generated during the modification process