PEMODELAN KOMPUTASIONAL SIFAT MEKANIK THIN FILM BERBASIS PEKTIN KULIT DURIAN - Rizkiarna, Reffany Choiru; Timur, Fajar; Sujiwa, Akbar; Wardhani, Primasari Cahya (Prodi Fisika FMIPA Universitas Negeri Surabaya, 2025)
Abstrak Pektin yang diekstrak dari kulit durian merupakan salah satu bentuk pemanfaatan limbah biomassa berpotensi tinggi sebagai material ramah lingkungan, khususnya untuk aplikasi kemasan pangan biodegradable. Pada penelitian ini dilakukan simulasi numerik berbasis COMSOL Multiphysics untuk menganalisis perilaku mekanik film tipis pektin kulit durian di bawah berbagai kondisi pembebanan. Studi dilakukan dengan membangun model tiga dimensi (3D) film tipis, kemudian pemetaan tegangan von Mises, analisis distribusi tegangan, serta evaluasi nilai tegangan maksimum (peak stress), minimum, dan rata-rata. Hasil simulasi menunjukkan distribusi tegangan tidak merata di seluruh volume film, melainkan terkonsentrasi pada tepi dan sudut akibat efek geometri. Nilai peak stress berfluktuasi terhadap waktu dan cenderung meningkat pada siklus pembebanan tertentu, yang berimplikasi pada potensi inisiasi retakan di area kritis. Meskipun demikian, sebagian besar area film masih berada dalam kondisi elastis, sehingga deformasi bersifat reversibel. Analisis ini menegaskan bahwa ketahanan jangka panjang film tipis pektin dipengaruhi oleh kombinasi sifat intrinsik material, kondisi batas, serta variasi pembebanan. Temuan ini memberikan dasar penting bagi pengembangan material kemasan berbasis pektin kulit durian yang lebih andal melalui modifikasi struktur maupun penambahan aditif penguat. Abstract Pectin extracted from durian rind represents a promising valorization of biomass waste with potential applications as an eco-friendly material, particularly for biodegradable food packaging. In this study, a COMSOL Multiphysics-based numerical simulation was conducted to investigate the mechanical behavior of durian rind pectin thin films under various loading conditions. A three-dimensional (3D) thin-film model was developed, followed by von Mises stress mapping, stress distribution analysis, and evaluation of maximum (peak stress), minimum, and average stress values. The results revealed that stress distribution was not uniform across the film volume but concentrated along the edges and corners due to geometric effects. Peak stress exhibited temporal fluctuations and tended to increase during specific loading cycles, indicating a high probability of crack initiation in critical regions. Nevertheless, the majority of the film remained within the elastic regime, allowing reversible deformation. This analysis highlights that the long-term reliability of durian pectin thin films is strongly governed by the interplay of intrinsic material properties, boundary conditions, and loading variations. The findings provide a scientific basis for further optimization of durian rind pectin films through structural modification or reinforcement additives to enhance their performance as sustainable packaging materials.