Electronic Theses and Dissertation

Keterbatasan plastik konvensional dalam hal degradasi lingkungan mendorong pengembangan material alternatif berbasis polimer biodegradabel. Penelitian ini bertujuan untuk membuat film biokomposit ramah lingkungan berbahan dasar Polyvinyl Alcohol (PVA) dengan ampas kopi yang telah dialkalisasi sebagai filler, serta gliserol sebagai plasticizer, dan menganalisis sifat mekanik serta kemampuan terdegradasi dari film biokomposit yang dihasilkan. Film biokomposit dibuat menggunakan metode solution casting dengan variasi konsentrasi ampas kopi sebesar 1%, 3%, dan 5%. Pengujian sifat mekanik dilakukan menggunakan standar ASTM D882 untuk uji tarik dan ASTM D1004 untuk uji sobek, sedangkan pengujian biodegradabilitas dilakukan menggunakan metode soil burial test mengacu pada standar ASTM D6400. Secara keseluruhan, hasil penelitian menunjukkan bahwa variasi ampas kopi 1% memberikan kombinasi sifat mekanik yang paling seimbang karena memiliki nilai regangan dan ketahanan sobek tertinggi, sedangkan variasi ampas kopi 3 % menghasilkan kekuatan tarik dan modulus elastisitas tertinggi. Pada variasi 5% terjadi penurunan sifat mekanik, ini disebabkan oleh lemahnya ikatan antarmuka antara filler dan matriks, aglomerasi partikel, serta ukuran partikel filler yang masih berada pada skala mikro. Seluruh variasi film biokomposit menunjukkan kemampuan biodegradasi yang sangat tinggi dengan laju kehilangan massa sebesar 100% hanya dalam waktu 1 hari pengujian. Hasil ini membuktikan bahwa film biokomposit bersifat biodegradabel dan berpotensi dikembangkan sebagai alternatif kemasan ramah lingkungan, meskipun diperlukan optimasi lebih lanjut terutama pada pengecilan ukuran partikel ampas kopi menuju skala nano untuk meningkatkan sifat mekaniknya.
Kata kunci: Ampas kopi, Alkalisasi, Biodegradabel, Film Biokomposit, Gliserol, PVA, Sifat Mekanik

The limited environmental degradability of conventional plastics has driven the development of alternative materials based on biodegradable polymers. This study aims to develop an environmentally friendly biocomposite film using Polyvinyl Alcohol (PVA) as the matrix, alkali-treated spent coffee grounds as the filler, and glycerol as the plasticizer, as well as to evaluate the mechanical properties and biodegradability of the resulting biocomposite films. The biocomposite films were fabricated using the solution casting method with spent coffee ground concentrations of 1%, 3%, and 5%. Mechanical properties were evaluated through tensile testing in accordance with ASTM D882 and tear testing based on ASTM D1004, while biodegradability was assessed using the soil burial test referring to ASTM D6400. Overall, the results indicate that the biocomposite film containing 1% spent coffee grounds exhibited the most balanced mechanical performance, showing the highest elongation at break and tear resistance, whereas the 3% variation achieved the highest tensile strength and elastic modulus. A decline in mechanical properties was observed at the 5% filler content, which was attributed to weak interfacial bonding between the filler and the polymer matrix, particle agglomeration, and the filler particle size remaining in the microscale range. All biocomposite film formulations demonstrated excellent biodegradability, achieving 100% mass loss within only one day of soil burial testing. These findings confirm that the developed biocomposite films are biodegradable and have significant potential as environmentally friendly packaging materials. However, further optimization, particularly through reducing the spent coffee ground particle size to the nanoscale, is recommended to improve their mechanical performance. Keywords: Alkali treatment, Biocomposite film, Biodegradable, Glycerol, Mechanical properties, Polyvinyl Alcohol (PVA), Spent coffee grounds.