Electronic Theses and Dissertation

Pengembangan material terurai hayati penting untuk mengatasi limbah plastik. Dalam konteks ini, ampas kopi berpotensi sebagai sumber nanoselulosa dalam komposit biopolimer ramah lingkungan. Penelitian ini bertujuan untuk mengevaluasi pengaruh komposisi polyvinyl alcohol (PVA), nanoselulosa (CNC), dan zinc oxide (ZnO) terhadap sifat fisik, kimia, mekanik, dan degradasi film komposit, serta menentukan formulasi optimal menggunakan metode Response Surface Methodology (RSM). Proses pembuatan film hybrid komposit dilakukan dengan menggunakan metode casting dan evaporasi. Karakterisasi dilakukan menggunakan SEM, FTIR, XRD, TGA, uji tarik, uji sobek, serta uji biodegradasi metode soil burial. SEM menunjukkan bahwa 1% ZnO terdispersi dengan baik, namun konsentrasi lebih tinggi (3–5%) menyebabkan aglomerasi signifikan. Hal ini mengganggu susunan rantai polimer dan menurunkan kristalinitas secara progresif, dikonfirmasi oleh XRD. FTIR membuktikan keberhasilan penggabungan komponen. TGA menunjukkan bahwa meskipun ZnO menurunkan suhu dekomposisi awal, stabilitas termal meningkat pada suhu tinggi. Secara mekanis, film mengalami penurunan kekuatan tarik dan ketahanan sobek masing-masing sebesar 61,85% dan 25,57% dibandingkan film PVA murni akibat aglomerasi ZnO. Namun, ketahanan sobek sedikit membaik pada konsentrasi ZnO lebih tinggi karena aglomerat menghalangi perambatan retak. Semua film terdegradasi sepenuhnya dalam tujuh hari pada uji penguburan tanah, menegaskan sifat ramah lingkungannya. Optimasi menggunakan Response Surface Methodology (RSM) menunjukkan komposisi optimal pada 10 b/v% PVA, 1,17 wt% CNC, dan 1,39 wt% ZnO, dengan kekuatan tarik 16,38 MPa dan ketahanan sobek 10 N. Hasil ini menunjukkan potensi film komposit hybrid sebagai alternatif plastik biodegradable untuk aplikasi berkelanjutan.

The development of biodegradable materials is crucial to address plastic waste. In this context, coffee grounds hold strong potential as a source of nanocellulose in the development of environmentally friendly biopolymer composites. This study aims to evaluate the effect of polyvinyl alcohol (PVA), nanocellulose (CNC), and zinc oxide (ZnO) compositions on the physical, chemical, mechanical, and degradation properties of composite films, and to determine the optimal formulation using Response Surface Methodology (RSM). The hybrid composite films were fabricated using casting and evaporation methods. Characterizations were performed using SEM, FTIR, XRD, TGA, tensile testing, tear testing, and soil burial biodegradability testing. SEM analysis showed that 1% ZnO was well dispersed, while higher concentrations (3–5%) led to significant agglomeration. This disrupted the polymer chain arrangement and progressively reduced crystallinity, as confirmed by XRD. FTIR analysis verified the successful integration of all components. TGA results revealed that although ZnO lowered the initial decomposition temperature, it improved thermal stability at higher temperatures. Mechanically, the films experienced a decrease in tensile strength and tear resistance by 61.85% and 25.57%, respectively, compared to pure PVA films, due to ZnO agglomeration. However, tear resistance slightly improved at higher ZnO concentrations, as the agglomerates hindered crack propagation. All films completely degraded within seven days in the soil burial test, confirming their eco-friendly nature. RSM optimization indicated the optimal composition at 10 b/v% PVA, 1.17 wt% CNC, and 1.39 wt% ZnO, yielding a tensile strength of 16.38 MPa and tear resistance of 10 N. These results highlight the potential of hybrid composite films as biodegradable plastic alternatives for sustainable applications.