Mechanical and thermal properties of plasticized polylactic 15 acid and thermoplastic sago starch for packaging

Abstract EN

The mechanical and thermal properties of Polylactic acid (PLA) plasticized with Triethyl Citrate (TC); PLA with thermoplastic sago starch (TSS) has been investigated.

The plasticized PLA (PPLA) and PLA/TSS blends were prepared with various contents of triethyl citrate and thermoplastic sago starch respectively in order to obtain biodegradable plastic material with a range of different mechanical properties that can be suitable for packaging applications.

The blends were melted using twin-screw extruder.

The samples obtained were investigated in terms of the effect of TC and TSS additions to the PLA on thermal glass transitions and mechanical properties of the resulting blends.

The blends were characterized using DSC for thermal transitions and by Instron testing machine for tensile strength, young modulus, elongation, and general toughness.

The addition of a plasticizer TC to a polymer PLA decreased the tensile strength and young modulus while increased the elongation at break and toughness.

The addition of TC also shifted the glass transition temperature (Tg) down to lower temperatures and no crystallization of PLA was observed.

The behavior of the PLA/TSS blends did not follow the same trend in all the compositions.

Tensile strength and modulus decreased for PLA/TSS blends with 10% and 30% of TSS when compared to pure PLA, the elongation at break decreased insignificantly and no improvement in toughness was observed.

On the other hand, PLA/TSS blend with 20% TSS had the highest tensile strength and elongation, but lowest modulus compared to pure PLA and other blends.

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