Content area
Full Text
ABSTRACT
The aims of the study were to investigate the effect of poly(ε - caprolactone) (PCL) and nano- SiO^sub 2^ within the thermoplastic starch (TPS) blends on the rate and extent of starch enzymatic hydrolysis using enzymes α-amylase and amyloglucosidase. The results of this study have revealed that blends with nano-SiO^sub 2^ content at 6 wt% exhibited a significantly reduced rate and extent of starch hydrolysis. The results suggest that this may have been attributed to interactions between starch and nano- SiO^sub 2^ that further prevented enzymatic attack on the remaining starch phases within the blend. The total solids that remained after 6000 min were 52 wt. % (TPS: PCL); 59 wt.% (TPS: PCL: 2% nano-SiO^sub 2^); 64 wt.% (TPS: PCL: 4% nano-SiO^sub 2^); 67 wt.% (TPS: PCL: 6% nano-SiO^sub 2^). The rate of glucose production from each nanocomposite substrates was most rapid for the substrate without nano- SiO^sub 2^ and decreased with the addition of nano- SiO^sub 2^, for TPS: PCL blend (374 µg/ml.h), 246 µg/ml.h (TPS: PCL: 2% nano- SiO^sub 2^), 217 µg/ml.h (TPS: PCL: 4% nano- SiO^sub 2^) and 199 µg/ml.h for (TPS: PCL: 6% nano- SiO^sub 2^). Enzymatic degradation behaviour of TPS: PCL: nano- SiO^sub 2^ was based on the determinations of Water resistance, Weight loss and the Reducing sugars.
Keywords: Nanocomposites; Polymer composites; Biodegradable polymers; Water resistance; Reducing sugars.
INTRODUCTION
Biodegradable polymers have been extensively investigated since the 1970s in order to protect the environment from non- biodegradable plastic wastes [1, 2]. Among such compounds, starch has received much attention in its use as biodegradable packaging materials because it is readily available at a low cost and has very fast biodegradability [3, 4]. Apart from favorable physico-chemical and mechanical properties, a biodegradable polymer to be used in medical applications needs to be biocompatible in a specific environment and its degradation products should not be cytotoxic.
The use of synthetic degradable polymers as biomaterials implies they are biocompatible by themselves and the use of particular additives and/or processing technologies should not interfere with the biocompatible behaviour [5]. Among biodegradable polymers, poly (?-caprolactone) (PCL), a synthetic aliphatic polyester, has been widely used in medical, packaging and agricultural applications because of its excellent mechanical properties, including its flexibility. The major disadvantage...