Tinjauan karakteristik foam plastik mikroseluler polistirena dengan penambahan aditif pada teknologi superkritis

Abstract

Processing technology of microcellular plastic represents development of foaming conventional plastic process. The processing of microcellular plastic has been acknowledged as eco-friendly technology because this plastic is produced by the use of benign supercritical carbon dioxide gas as blowing agent. In this work, the samples polystyrene and additive were saturated with supercritical CO2 at various saturation pressures from 10-22 MPa (at around glass transition temperature of 95 oC and 80 oC) When the saturation time was accomplished, the solution was decompressed rapidly into atmospheric pressure. The samples were placed in the vessel heated and completed by flowing of carbon dioxide as cooler gas into the vessel. The samples were characterized to observe volume expansion ratio, cell density, average cell diameter and surface fractured with Scanning Electron Microscopy. The microcellular foam of plastic product of PS system has cell diameter between 3.970-9.933 μm , cell density between 9.14x104 – 6.24x109 cell/ cm3. PS-CaCO3 system has cell diameter between 3.501-8.050 μm, cell density between 3.31x107 – 1.10x1011 cell/cm3, while PS-coconut fiber system hascell diameter between 2.520-8.414 μm, cell density between 1.50x108 -1.60x1010 cell/cm3 at various pressure.Keywords: polystyrene, microcellular foam plastic, supercritical CO2, CaCO3additive, coconut fiber additive. AbstrakProses pembuatan plastik mikroseluler merupakan pengembangan dari proses pembuatan foam plastik konvensional. Plastik mikroseluler menggunakan fluida superkritis seperti CO2 dan N2 sebagai blowing agent yang ramah terhadap lingkungan, sehingga proses pembuatan foam plastik mikroseluler dikenal sebagai teknologi ramah lingkungan. Penelitian ini menggunakan sampel polistirena yang dicampur dengan partikel kalsium karbonat atau sabut kelapa dengan konsentrasi 5% yang diproses pada kondisi tekanan 10-22 MPa (T = 95 oC dan 80 oC). Setelah kondisi yang diinginkan tercapai dilakukan dekompresi secara mendadak menuju tekanan atmosfer, dan dilanjutkan dengan proses pemanasan, diakhiri dengan mengalirkan gas CO2 sebagai pendingin. Selanjutnya sampel dikarakterisasi untuk mengetahui rasio volume ekspansi foam, densitas sel, diameter rata-rata sel dan struktur foam yang dihasilkan dengan Scanning Electron Microscope. Pada penelitian ini didapatkan pada sistem PS Murni menghasilkan diameter sel antara 3,970-9,933 μm dan densitas sel 9,14x104 - 6,24x109 cell/cm3. Sistem PS-CaCO3 menghasilkan diameter sel antara 3,501-8,050 μm dan densitas sel 3,31x107 - 1,10x1011 cell/cm3, dan pada sistem PS-Sabut kelapa menghasilkan diameter sel antara 2,520-8,414 μm dan densitas sel 1,50x108 - 1,60x1010 cell/cm3 pada berbagai variasi tekanan.Kata kunci : polistirena, foam plastik mikroseluler, CO2 superkritis, aditif CaCO3, aditif sabut kelapa.