“Pemanfaatan material komposit pada saat ini semakin berkembang, seiring dengan meningkatnya penggunaan bahan tersebut yang semakin meluas mulai dari yang sederhana sampai sektor industri. Hal ini dikarenakan karakteristik material komposit mempunyai banyak kelebihan dibandingkan dengan jenis bahan lain yaitu ringan, kuat, tidak terpengaruh korosi dan mampu bersaing dengan logam, dengan tidak kehilangan karakteristik dan kekuatan mekanisnya. Penelitian ini bertujuan untuk mengetahui pengaruh variasi waktu sintering dan komposisi terhadap ketangguhan impak dan kekerasan komposit Eceng Gondok-PVC-LDPE. Bahan yang digunakan merupakan tanaman gulma dan limbah plastik. Proses pembuatan spesimen dilakukan dengan metode pressured sintering, yaitu dengan cara pembuatan serbuk, dan di screening 60 mesh. Selanjutnya serbuk di mixing dengan variasi komposisi perbandingan K1: EG 50%, PVC 10%, LDPE 40%; K2: EG 55%, PVC 10%, LDPE 35%; K3: EG 60%, PVC 10%, LDPE 30%; K4: EG 65%, PVC 10%, LDPE 25% dan K5: EG 70%, PVC 10%, LDPE 20% dan dikompaksi dengan tekanan 1,013 bar. Selanjutnya di sintering dengan temperatur 1800C. Pada penilitian ini variasi waktu sintering yaitu; 5 menit, 8 menit, 10 menit, 13 menit dan 15 menit. Sifat mekanik dilihat dari nilai kekerasan dan impak dengan menggunakan standar ISO 2039-1:2001, ISO 179-1:2010. Selain itu menganalisis morfologi dengan Scanning Electron Microscope (SEM). Pengujian untuk sifat kimia dilihat dengan analisis morfologi SEM. Berdasarkan hasil pengujian sifat mekanik didapatkan nilai kekerasan tertinggi dimiliki oleh komposit K2 sebesar 22.30 MPa dan 2.1 kJ/m2 untuk nilai impak.” Kata kunci: eceng gondok, komposit, LDPE, pressured sintering, PVC. Abstract“The utilization of composite materials nowadays is currently growing, along with the increasing use of these materials, which are expanding ranging from the small scale to the industrial sector. This is because the characteristics of composite materials have many advantages compared to other types of materials i.e. light, strong, not affected by corrosion and able to compete with metals without losing their mechanical characteristics and strength. This research aims to determine the effect of variations in sintering time and it’s composition against impact toughness and hardness of the Water Hyacinth-PVC-LDPE composite. The materials used are weeds and plastic waste. The process of specimen fabrication was performed by using pressured sintering method, i.e. by making it into powder and were screening by using screen 60 mesh. Furthermore, the powder were mixed with the variation of the composition K1: EG 50%, PVC 10%, LDPE 40%; K2: EG 55%, PVC 10%, LDPE 35%; K3: EG 60%, PVC 10%, LDPE 30%; K4: EG 65%, PVC 10%, LDPE 25% dan K5: EG 70%, PVC 10%, LDPE 20% and compacted with a pressure of 1,1013 bar. After that is sintering with temperature 180oC. In this research the sintering time variations is 5 minute, 8 minute, 10 minute, 13 minute and 15 minute. Mechanical properties if were seen from the hardness and impact values by using a standard ISO 2039-1:2001, ISO 179-1:2010. In additions to analyze the morphology by using a Scanning Electron Microscope (SEM). Tests for chemical properties can be seen with the morphological analysis of SEM. Based on the testing results, the mechanical properties obtained the highest hardness value owned by a composite K2 by 22.30 MPa and 2.1 kJ/m2 for the value of the impact.” Kata kunci:water hyacinth, composite, LDPE, pressured sintering, PVC.
CRACK PROPAGATION STUDIES OF A RUBBER-TOUGHENED EPOXY RESIN IN THE SCANNING ELECTRON MICROSCOPE