Elastic Properties of Bio Based Polyamide (PA) Materials

<br/><b>In this chapter, bio (castor oil) based polyamide material was compared with petroleum (hydrocarbon) based polyamide. Here the effect of aging (high temperature and high humidity) on strength at yield and breaking, strain at breakage, elastic modulus were studied. Three different aging conditions were investigated - 40o C 90% RH, 60o C 90% RH and 85o C 85%RH up to 500 Hrs. Satisfactory dimensional stability (within ±2% change) was observed in width and thickness over all conditions. Breaking strength was found to decrease as the aging stress or aging time (with the same aging condition) was increased. Even though no cosmetic or appearance changes were noticeable, around 12%, 27% and 33% drop in strength at breakage was observed after 500 hours for the three different aging conditions respectively. Strain at breakage was found to increase at 40o C 90% RH but as the stress increased to 60o C 90% RH and 85o C 85%RH, decreased strain was observed which indicates toughening due to the plasticizing effect. The opposite effect was observed in strength at yield and can be attributed to water absorption leading to plasticization and enhanced ductility. Life data analysis (B10, Weibull and Weibull β) were also compared between castor oil and petroleum based polyamide materials.</b>