MECHANICAL, DIFFUSION AND DEGRADATION PROPERTIES OF BLENDS OF CELLULOSE AND RECYCLED LOW DENSITY POLYETHYLENE

Abstract

This  paper  discusses  the effect  of  Cellulose  (CEL)  concentration  on  mechanical,  diffusion  and  degradation properties  of  Recycled  Low  Density  Polyethylene  (RHDPE).  Injection  molded  blends  of  RLDPE  and  CEL  were prepared  in  percentage  ratios  of  100:0,  95:5,  90:10,  85:15  and  80:20.  Dynamic  mechanical  analysis,  creep, diffusion, thermal degradation and biodegradation measurements were carried out on the molded samples. Three relaxation processes  namely;  α,  β1 and β2 were observed. The  α process  is  assigned to large  scale  chain  motion where as β1 and β2 suggest lamellae shear of two different thicknesses. The intensities of the processes decreased with  increase  in  cellulose  loading  whereas  the  temperature  shifts  were  not  observed. Creep  strain  increased moderately  with  increasing  loading  intakes  while  recovery  decreased.  Deformation  behavior  follows  WLF  law suggesting that free volume plays a crucial role. Water uptake was found to increase with cellulose loading. Weight change  profiles  for  the  blends  at  room  temperature  indicated  that  the  diffusion  is  Fickian.  Diffusion  coefficient increased with CEL intake. Thermo-gravimetric analysis (TGA) showed that the decomposition trend shifted from one stage to two stage with increasing CEL intake. The models of analysis for DMA and Creep data were VFT and WLF  respectively.  Thermal  degradation  data  was  analyzed  using  Arrhenius  laws  while  Fick’s  laws  were  used  in diffusion measurements. Energy is distributed through the three transitions on impact. Creep increases with CEL intake  whereas  recovery is  improved.  Diffusivity  increases  while  thermal  stability  as  well  as  toxic  byproducts decreased  with  CEL  intake.  Degradation  was  enhanced  with  CEL  intake  thus  the  composites  can  be  adopted  by policy makers to minimize environmental pollution. 

Key  words:  Recycled  Low  Density  Polyethylene  (RLDPE),  cellulose  (CEL),  Thermo-gravimetric  analysis  (TGA), William Landel Ferry (WLF), Dynamic Mechanical Analysis (DMA)