||In this study, various chain length acids (C6, C8, C10 and C12) modified by methane sulfonic acid (MSA) and temperature were used to modify tapioca starch(ST), then the glycerol (GA) were added into modified starch, to prepare a new blends.The mechanical properties, thermal properties and physical properties of blends were studied. This investigation was divided into two parts.
In section 1, the new biodegradable materials were use of starch and glycerol with hexanedioic acid (HA), suberic acid (SBA), sebacic acid (SA), decanedicarboxylic acid (DA) manufacturing with different temperatures (90℃, 110℃and 130℃). And then the solution was added into modified starch to prepare the blends by using single-screw extruder. The FT-IR patterns indicated that the characteristic peak of C=O in ester was observed at 1730cm-1. It proved that different chain length acids (C6, C8, C10 and C12) was reacted with glycerol by esterification and was used to plasticize blends during extrusion. In addition, the blends would improve the hydrolysis and thermal stability. The water contact angle increased from 43.0° to 64.0°.
In section 2, the HA blend (110℃), SBA blend (110℃), SA blend (110℃), DA blend (130℃) was used in study, because they possessed good mechanical properties, water resistances and thermal stability. In this part, the various contents (0, 0.005, 0.010, 0.020g) of MSA were also used to modify the mechanical properties of blends. We observed that the blends were added to MSA, and then the FT-IR patterns indicated the C=O in ester was appeared at 1730 cm-1 present. For this reason, the hydrophobic blends were produced. The water contact angle of the MSA blends increased from 55.0° to 71.0°. Although break elongation of the MSA blends reduced from the original 220% to 128%, the stress increased from 2.5 MPa to 5.1 MPa. Therefore, the optimal composition of blends was the DA blend (130℃) added to MSA(0.005g).