Effectiveness of triacetin and triethyl citrate as plasticizer in polyvinyl alcohol

• Published in: Materials today : proceedings Vol. 17; pp. 560 - 567
• Main Authors: Zuber, S.A.N. Ahmad, Rusli, A., Ismail, H.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 2019
• Subjects: Plasticized polyvinyl alcohol; Triacetin; Triethyl citrate; Triacetin; Triethyl citrate; Plasticized polyvinyl alcohol
• ISSN: 2214-7853; 2214-7853
• DOI: 10.1016/j.matpr.2019.06.335

The main objective of this work was to investigate the applicability of two natural based plasticizers (triacetin (TRI) and triethyl citrate (TEC)) in two polyvinyl alcohol (PVA) with similar molecular weight but different hydrolysis degree (88% and 99%). The PVA and plasticizers were mixed by solvent blending method and the PVA solution was casted to produce plasticized PVA. It was found that, at a fixed amount of plasticizer (10%), TRI caused reduction of glass transition temperature (Tg) and melt temperature (Tm) in both PVA with the largest reduction in 88% hydrolysed PVA while TEC showed insignificant changes of Tg and slight reduction of Tm suggesting higher effectiveness of plasticization in 88% hydrolysed PVA (PVA88) with TRI. Morphological studies suggesting phase separation in triethyl citrate plasticized PVA. Variation of TRI amounts in PVA88 indicated that both Tg and Tm reduced with increasing TRI up 15% and then plateaued with 20%TRI. Tensile strength and modulus slightly reduced up to 10%TRI but suddenly increased with 15%TRI while continuous increased in elongation at break with TRI loading. Morphological study indicated smooth surface up to 10wt% PVA but rough with large number of tear lines and void and also indicated dual phase morphology with formation of fibrillar PVA with more than 15%TRI which is believed might responsible for the improvement of tensile strength and modulus in 85PVA88/15TRI.