MECHANICAL PROPERTIES, SHRINKAGE BEHAVIOR AND WATER ABSORPTION OF PA6/PP/CAC03 NANOCOMPOSITES

Iranian Journal of Polymer Science and Technology Vol. 24, No. 6, 481-492 February March 2012 ISSN: 1016-3255 PA6/PP nanocomposite, nano-CaCO3, water absorption, mechanical properties, shrinkage Nanocomposites based on polyamide 6/polypropylene )PA6/PP 67/33) blend containing 2.5 to 10 phr of nano-CaCO3 and 5 phr of maleated polypropylene )PP-g-MAH) as compatibilizer were prepared by melt compounding followed by injection molding. The mechanical properties, water absorption, as well as shrinkage behavior were characterized and the morphology was studied using scanning electron microscopy. The presence of PP, PP-g-MAH and nano-CaCO3 lowered the amount of water absorption as high as 72 wt%. Morphology analysis indicated that the addition of PP-g-MAH can significantly improve the adhesion between PA6 and PP phases. The incorporation of PP-g-MAH led to 24% increase in flexural and impact strength, 27% rise in tensile strength and approximately 100% increase in elongation-at-break. The addition of nano-CaCO3 particles increased the impact resistance and flexural strength. The results of experiments indicated that the maximum flexural strength was achieved by adding 5 phr of nano-CaCO3 which was 16% greater than pure PA6, and the maximum impact strength was attained by adding 7.5 phr of nano-CaCO3 which was 29% superior compared to pure PA6. The incorporation of 10 phr of nanoCaCO3 particles led to filler agglomeration and, consequently, the impact strength was dramatically dropped. Dimensional characterization of molded samples revealed that the incorporation of PP-g-MAH can raise the shrinkage, but the addition of nanoCaCO3 has not had any considerable effect on the shrinkage of nanocomposites. )*)To whom correspondence should be addressed. Eـmail: shelesh-nezhad@tabrizu.ac.ir Mechanical Properties, Shrinkage Behavior and Water Absorption of PA6/PP/CaCO3 Nanocomposites Karim Shelesh-Nezhad*, Saeed Montakhabi-Kalajahi, and Javad Ehsani-zonuz Department of Manufacturing Engineering, Faculty of Mechanical Engineering, University of Tabriz, P.O. Box: 51665-315, Tabriz, Iran Received 25 August 2011, accepted 13 February 2012