2.3. Characterizations
Samples were moulded for flexural, according to ASTM D 790M, ASTM D 638 and ASTM D 4508 stan dards, respectively. All tests were carried out under an ambient condition. Universal MTS system was utilized for the tensile test in the current study. Grip separation was set to 100 mm in length and the crosshead speed was adjusted to 5 mm/min for the tensile test. Samples were further coated by gold for scanning electron microscope (SEM) UEOL Model JSM-6490) imaging to observe the frac surface of neat PLA and BC/PLA composites. Flexural moduli in bending and flexural strength of the samples were measured through universal MTS system under an ambient condition. The default radii of the loading nose and supports were 5.0 mm. The crosshead peed of the flexural strength tests was 0.946 mm/min An instrumented drop weight impact tester (Instron Dynatup) was selected to perform falling weight impact test under ambient condition to study the impact properties including maximum load (Pmax), crack initiation energy (Em), propagation energy (Ep), total fracture energy (Et) and ductility index (DI). Brinell hardness testing was conducted using 15 kgf load and 1.5875 mm diameter indenter. The loading time was about 10 s according to ASTME10 Standard Test Method
DSC and TGA measurement were made with a Thermogravi metric analyser/Differential Scanning Calorimeter (Netzch TGAl DSC) Sample of 5-10 mg were placed in ceramic pan with cover and heated from 25 octo 800 oCat the rate of 10 oClmm. Other than the glass transition temperature (Tg), crystallization temperature (Te), melting temperature (Tm), experimental melting enthalpy (AHm) and degree of crystallinity (X%) were measured. The ther- mal degradation properties taking into account were the To (oC) and Tr (OC) as the temperatures for starting and finishing PLA degradation
High resolution X-ray diffractometer (HRXRD) analysis was carried out by Rigaku SmartLab system for phase identification of the samples. Scattered radiation was recorded in 20 range from 5 to 400 at 5°/min in reflection mode. For compost biodegradability test, the samples were carried out in soil having initial pH value 6.32 at temperature 37 oc. Water was added frequently to keep the hu midity of the soil. The weight loss of composted sample can be evaluated using the following equation: