STUDY OF THE INTERACTIONS AND THERMAL PROPERTIES BETWEEN CHITOSAN AND LINEAR LOW DENSITY POLYETHYLENE FUNCTIONALIZED AND MOLECULAR MODELING

Abstract

Synthesis and study of biodegradable plastics from natural sources such as chitosan (Q) is one of the scientific and  industrial  challenges  currently  most  studied.  In  this  sense,  from  the  linear  low  density  polyethylene (LLDPE)  binary  blends  of  polyolefins/Q  were  studied.  For  promote  interactions  in  the  blends,  it  carried  out chemical modification of LLDPE with acrylamide (AAm) for use as compatibilizing agent in the preparation of blends  LLDPE/Q.  Subsequently,  LLDPE/Q  and  LLDPE/Q/LLDPE-g-AAm  blends  were  characterized  using the  technique  differential  scanning  calorimetry  (DSC)  and  FTIR-ATR  Spectroscopy.  Thermal  analyzes  show that  the  degree  of  crystallinity  of  the  blend  PELBD/Q  (90/10)  decreases  with  Q  content,  it  is  postulated  that must be a problem  of "molecular confinement"  which interferes  with the  growth  of crystals. Also through the FTIR-ATR  it  could  be  detected  specific  interactions  between  amide  compatibilizing  agent  and  OH  and  NH2 groups of chitosan. Understanding the interactions that occur can be effected by means of molecular modeling, which was performed with the software package Gaussian 09 W, at the level of theory B3LYP/6-31++ G (d,p), confirming  that  stronger  interactions  occur  with  the  addition  of  compatiblizante  agent  in  a  physical  mixture between LLDPE/Q.