STUDI SIFAT MEKANIKA KOMPOSIT HIBRID UNSATURATED POLYESTER/CLAY/SERAT GELAS

Husaini, Prof. Dr. Ir. Kusmono., S.T., M.T., IPM., ASEAN Eng

2011 | Tesis | S2 Teknik Mesin

Munculnya issue bahwa material harus high-perfomance dalam hal kekuatan, kekakuan, ketangguhan, ringan dan murah. Sifat dari polimerik termoset jenis unsaturated polyester yang bersifat brittle dan sensitif terhadap retak dapat diperbaiki dengan penambahan serat gelas dan clay dalam jumlah tertentu. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh penambahan clay terhadap kekuatan tarik, kekuatan bending, modulus elastisitas bending, kekuatan impak dan ketangguhan retak dari komposit unsaturated polyester/serat gelas. Metode handy lay-up digunakan untuk persiapan benda uji. Bahan-bahan yang digunakan dalam penelitian ini adalah resin unsaturated polyester, clay, serat gelas dan hardener methyl ethyl ketone peroxide.Unsaturated polyester dicampur clay dengan variasi clay 0, 2, 4 dan 6% berat diaduk dengan menggunakan mechanical stirrer kecepatan putar 800 rpm selama 120 menit pada temperatur 60 oC. Campuran didinginkan selama 10 menit, ditambahkan hardener 1% berat, diaduk selama 2 menit dan dimasukkan dalam tabung hampa selama 2 menit. Komposit hibrid tersusun dari matrik unsaturated polyester/clay dan lembaran serat gelas dengan ukuran 190 x 220 mm2 sejumlah 4 lembar. Komposit hibrid unsaturated polyester/clay/serat gelas dibuat dengan cara mula-mula matrik unsaturated polyester/clay dituang di atas cetakan logam. Kemudian lembaran pertama dari serat gelas diletakkan di atas matrik dan dipadatkan dengan rol. Matrik dituangkan diatas lembaran serat gelas pertama dan diikuti lembaran serat gelas yang kedua diletakkan di atas matrik. Proses ini diulang sampai 4 lembaran. Setelah didiamkan selama 24 jam pada suhu kamar, komposit hibrid unsaturated polyester/clay/serat gelas dipanaskan pada temperatur 80oC selama 3 jam. Selanjutnya benda uji dibuat dengan cara dipotong menggunakan mesin gergaji scroll saw. Hasil penelitian menunjukkan bahwa kekuatan tarik, kekuatan bending dan modulus elastisitas bending tertinggi dari komposit hibrid unsaturated polyester/clay/serat gelas dicapai pada clay 2% dengan kenaikan kekuatan tarik sebesar 12,83%, kekuatan bending sebesar 21,12% dan modulus elastisitas bending sebesar 11,15%, tetapi penambahan clay lebih dari 2% berat menurunkan kekuatan tarik, kekuatan bending dan modulus elastisitas bending. Kekuatan impak dan ketangguhan retak tertinggi dari komposit hibrid unsaturated polyester/clay/serat gelas dicapai pada clay 4% dengan kenaikan kekuatan impak sebesar 26,19% dan ketangguhan retak sebesar 14,43%, tetapi penambahan clay lebih dari 4% berat menurunkan kekuatan impak dan ketangguhan retak.

The issue that material must high-perfomance in strengthness, stiffness, toughness, lighter and cheaper. The properties of polymeric thermoset of unsaturated polyester were brittle and crack sensitive can be repaired by added fiber glass and clay in number of amount.The aim of this study was to determine the effect of the addition of clay on the tensile strength, bending strength, bending modulus of elasticity, impact strength and fracture toughness of the composite unsaturated polyester / glass fiber. Handy lay-up method was used for the preparation of the unsaturated polyester/clay/glass fiber hybrid composite. The materials used in this study was unsaturated polyester resin, clay, glass fiber and methyl ethyl ketone peroxide catalist into unsaturated polyester then clay using variations of 0, 2, 4 and 6 %wt were mixed stirred mechanically 800 rpm for 120 minutes at 60 o C. The mixture were cooled for 10 minutes, then added of 1 %wt catalist, stirred for 2 minutes and put in a vacuum oven for 2 minutes. Hybrid composite composed of unsaturated polyester / clay and 4 layers glass fiber by size 190 x 220 mm 2 . Firstly matrix of unsaturated polyester / clay was poured into a metal mold, then first ply of glass fibers layed on the matrix and compressed using rollers. The matrix was poured over the first ply of glass fiber and then placed a second ply of glass fiber. This process was repeated up to 4 plies glass fiber. After settling for 24 hours at room temperature, unsaturated polyester hybrid composite clay / glass fiber ware heated at a temperature of 80 °C for 3 hours. Furthermore, the spesimen was made by a “scroll saw” machine. Results showed that the highest value tensile strength, bending strength and bending modulus of elasticity were obtained in the hybrid composite unsaturated polyester / clay / glass fiber using 2 %wt of clay content. The pencentage increase by 12.83% tensile strength, 21.12% for bending strength, and 11.15% for bending modulus of elasticity. But impact strength and fracture toughness of the hybrid composite unsaturated polyester / clay / glass fiber was achieved on clay 4 %wt for the impact strength increas by 26,19% and by 14.43% fracture toughness.

Kata Kunci : unsaturated polyester, clay, serat gelas, komposit hibrid dan sifat mekanik