KARAKTERISASI SIFAT MEKANIS PART BIOKOMPOSIT [HYDROXYAPATITE/BIOPLASTIK/SERICIN] YANG DIBUAT MENGGUNAKAN MESIN PRINTER EKTRUSI 3 DIMENSI

AGRIS SETIAWAN, Ir. Alva Edy Tontowi, M.Sc., Ph.D.

2016 | Tesis | S2 Teknik Mesin

Hydroxiapatite sebagai bahan biokeramik yang compatible dengan tubuh digunakan untuk kebutuhan medis. Bioplastik terbuat dari cassava strach yang bersifat biodegradable. Sericin adalah protein yang telah diketahui mampu meningkatkan interaksi sel dengan material. Sericin terbuat dari cocoon ulat sutera bombyx mori. Biokomposit yang dikembangkan terdiri dari komposisi [Hydroxyapatite/Bioplastik/Sericin] berbentuk pasta untuk dicetak menjadi spesimen menggunakan mesin printer ektrusi tiga dimensi. Tujuan dari penelitian ini adalah mengkaji sifat mekanis dan struktur mikro dari pasta biokomposit [Hydroxyapatite/Bioplastik/Sericin] yang dicetak dengan menggunakan mesin printer ektrusi 3 dimensi. Subjek penelitian ini adalah pasta biokomposit yang terdiri dari hydroxyapatite (Sigma Aldrich), cassava starch (PT. Budi Starch & Sweetener TBK) dan sericin (Bombyx mori). Variasi komposisi biokomposit yaitu A(40% HA/60%bP); B( 50%HA/50%bP); C(60%HA/40%bP) dan D (70%HA/30%bP) tiap variasi komposisi ditambah sericin 0,3% w/w dari suspensi HA. Pengaturan gerak mesin printer ektrusi 3 D yaitu infill speed 60 mm/s, print speed 60 mm/s dan layer height 0,35 mm. Pengujian sifat mekanis yang dilakukan yaitu uji tarik dan uji lengkung. Dimensi spesimen uji lengkung disesuaikan dengan ASTM D 790 dan spesimen uji tarik disesuaikan dengan ASTM D 638 tipe 4. Pengamatan bentuk struktur mikro dan unsur menggunakan scanning electron microscope (SEM-EDX). Komposisi C [Suspensi HA 60%:40% Bioplastik] ditambah sericin 0,3% w/w dari suspensi HA mempunyai nilai rerata tertinggi kekuatan tarik/ tensile strength (sigma t) sebesar 2,51±0,45 MPa dan nilai rerata tertinggi kekuatan lengkung/flexural strength (sigma fs) yaitu sebesar 3,89±1,26 MPa. Hasil pengamatan menggunakan SEM tidak nampak agglomerasi HA dan partikel HA murni juga tidak nampak. Pada pengujian SEM-EDX diketahui struktur mikro berbentuk jarum/needle mempunyai unsur dominan O (Oxygen), unsur Ca (Calsium), P (Phospor) dan C (Carbon) pada kulit atom K.

Hydroxiapatite as bioceramics material that is compatible to the body and usually had been used for medical needs. Bioplastics made from cassava starch which is biodegradable, while sericin is made from Bombyx mori silkworm cocoons, a protein that has been known to increase the interaction of cells with the material. Biocomposites developed consisting of the composition [Hydroxyapatite/ Bioplastics/Sericin] in pasta form to be printed into specimens using extrusion machine three-dimensional printer. The aim of this study is to examine the mechanical properties and microstructure of pasta biocomposites [Hydroxyapatite/Bioplastic/Sericin] were printed using 3 D printer extrusion machine. The subjects were pasta biocomposite composed of hydroxyapatite (Sigma Aldrich), cassava starch and sericin (Bombyx mori). Variation of biocomposite composition is namely A (40 % HA/60 % bP); B (50 % HA/50 % bP); C (60 % HA/40 % bP) and D (70 % HA/30 % bP) each variation of composition were added with sericin 0.3 % w/w of the suspension HA. Motion 3 D bioprinter were set up with infill speed is 60 mm/s, print speed is 60 mm/s and the layer height is 0.35 mm. Mechanical properties test which is the flexural test and tensile test. Dimensions of flexural test specimen were adjusted on ASTM D 790 and tensile test specimens were adjusted on ASTM D638 Type 4. Observation of microstructure shape and element using a scanning electron microscope (SEM - EDX). Results of tensile test and flexural test obtained a composition which has the highest mechanical properties. Composition C [HA Suspension 60 %:40 % Bioplastic] added sericin 0.3 % w / w of the suspension HA has the highest mean value of tensile strength (sigma t) were 2.51± 0.45 MPa and the highest mean value of flexural strength (sigma fs) is 3.89 ± 1.26 MPa. The results of microstructure observation with SEM has known at shape and size of the microstructure biocomposites. HA agglomeration is not appear and also particle HA does not appear on the observations using SEM. In the SEM - EDX testing known needle-shaped microstructure has a dominant element of O (Oxygen), the element Ca (Calcium), P (Phosphorus) and C (Carbon) at the skin of atom (K).

Kata Kunci : biocomposite, hydroxyapatite, tensile strength, flexural strength, microstructure, 3 D printer extrusion machine