ANALISI VARIASI KOMPOSISI PVA/PATI TERHADAP KEKUATAN TARIK BIODEGRADIBILITAS BIOPLASTIK RAMAH LINGKUNGAN

Abstract

ABSTRACT

The use of conventional petroleum-based plastics remains an environmental problem because they are difficult to decompose naturally. Although bioplastics based on natural polymers have been widely developed, further investigation is needed to determine the appropriate composition of Polyvinyl Alcohol (PVA) and cassava starch that can provide a balance between mechanical properties and biodegradation. This study is important for developing an alternative packaging material with adequate mechanical strength and improved degradability in the environment. This study aimed to analyze the effect of variations in PVA and cassava starch composition on the mechanical properties and biodegradation of bioplastics and to determine the composition with the best characteristics. A laboratory experimental method using the solution casting technique was employed. The samples consisted of six variations of PVA at 3 Wt% and 5 Wt% combined with cassava starch at 0.6 Wt%, 0.9 Wt%, and 1.2 Wt%, with LDPE as a comparison. Mechanical properties were tested according to ASTM D882, while biodegradation was evaluated using a soil burial test for 12 days. The results showed that PVA 5 Wt% + 0.6 Wt% starch produced a tensile strength of 24.861 MPa, elongation of 72.907%, and Young's modulus of 548.46 MPa. The highest biodegradation was obtained from PVA 5 Wt% + 0.9 Wt% starch at 82.90%, compared with 1.49% for LDPE. Thus, composition variations produced different characteristics, and their selection should be adjusted to the intended application.

ABSTRAK

Penggunaan plastik konvensional berbasis minyak bumi masih menimbulkan permasalahan lingkungan karena sulit terurai secara alami. Meskipun bioplastik berbasis polimer alami telah banyak dikembangkan, masih diperlukan kajian mengenai komposisi PVA dan pati singkong yang mampu menghasilkan keseimbangan antara sifat mekanik dan biodegradasi. Penelitian ini penting untuk memperoleh alternatif material kemasan yang memiliki kekuatan mekanik memadai sekaligus lebih mudah terurai di lingkungan. Penelitian ini bertujuan menganalisis pengaruh variasi komposisi Polyvinyl Alcohol (PVA) dan pati singkong terhadap sifat mekanik dan biodegradasi bioplastik serta menentukan komposisi dengan karakteristik terbaik. Penelitian menggunakan metode eksperimen laboratorium dengan teknik solution casting. Sampel terdiri atas enam variasi PVA 3 Wt% dan 5 Wt% yang dikombinasikan dengan pati 0,6 Wt%, 0,9 Wt%, dan 1,2 Wt%, serta LDPE sebagai pembanding. Pengujian sifat mekanik mengacu pada ASTM D882, sedangkan biodegradasi diuji melalui soil burial test selama 12 hari. Hasil menunjukkan PVA 5 Wt% + pati 0,6 Wt% menghasilkan kuat tarik 24,861 MPa, elongasi 72,907%, dan modulus Young 548,46 MPa. Biodegradasi tertinggi diperoleh pada PVA 5 Wt% + pati 0,9 Wt% sebesar 82,90%, dibandingkan LDPE sebesar 1,49%. Dengan demikian, variasi komposisi menghasilkan karakteristik berbeda sehingga pemilihannya perlu disesuaikan dengan kebutuhan penggunaan.