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"Pengujian fatigue dilakukan pada material komposit fiber glass berjenis woven roving dengan epoxy sebagai matriksnya. Material yang diuji merupakan material yang lolos uji pada serangkaian uji mekanik statis sebelumnya, yaitu WR 200 asimetris epoxy dan WR 400 asimetris-epoxy. Material ini dibuat dengan metode Vacuum Assisted Resin Infusion (VARI) pada suhu ruang. Hasil pengujian fatigue dilanjutkan dengan ekstrapolasi data dari kurva S-N dengan Matlab 7.4 yang berisi curve fitting probabilitas kegagalan untuk memperkirakan masa pakai material. Hasil curve fitting menunjukkan material mempunyai daya tahan di atas siklus 108 untuk pemakaian sekitar 20 tahun. Hasil pengamatan dengan mikroskop optik dan Scanning Electron Microscope (SEM) menunjukkan mekanisme kegagalan material akibat uji fatigue, diawali dengan retaknya matriks, putusnya ikatan permukaan matriks-fiber, diikuti putusnya fiber yang menyebabkan patahnya material.

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Fatigue test was carried out on composite materials with the type of woven roving fiberglass with an epoxy as a matrix. The specification of the fatigue tested materials was selected from previous static mechanical tests, namely WR 200 asymmetric-epoxy and WR 400 asymmetric-epoxy. These materials were produced by using Vacuum Assisted Resin Infusion (VARI) at room temperature. The fatigue test result followed by extrapolation of data from the S-N curve with Matlab 7.4 curve fitting, which contains the probability of failure to estimate the lifetime of the materials.

Curve fitting results indicate the materials have a resistance above 108 cycles for the use of about 20 years. The observation with optical microscope and Scanning Electron Microscope (SEM) shows the mechanism of failure due to fatigue test, begins from a matrix cracking, followed by a fiber-matrix interfacial debonding, then a fiber breakage that caused the final fracture."

"Pada penelitian ini, nanokomposit clay-epoxy menggunakan Organo clay Nanomer I30E, epoxy resin DER 331 dan curing agent Versamid 125 disintesa dengan metode in situ polimerization. Sebagai pembanding, komposit serat gelas-epoxy menggunakan serat gelas komersial dan epoxy resin dan curing agent yang sama disintesa dengan metode wet laminating.Karakterisasi struktur internal dan permukaan fracture, yang masing-masing menggunakan XRD (X-Ray Diffraction) dan SEM (Scanning Electron Microscope), menunjukkan bahwa nanokomposit telah berhasil disintesa. Nanokomposit memiliki struktur eksfoliasi pada komposisi clay <7.34 (% berat) dan struktur eksfoliasi dan interkalasi pada komposisi clay ≥ 7.34 (% berat). Nanokomposit dengan komposisi clay 2.10 (% berat) terdiri dari fasa epoxy dan fasa aglomerasi clay dan memiliki tanda fracture berbentuk kerucut.Hasil uji tarik, tekan dan kekerasan menunjukkan bahwa nanokomposit, yang disintesa dengan teknik pencampuran DM (Direct Mixing), tidak layak digunakan untuk aplikasi struktural pada pesawat terbang menggantikan komposit serat gelas-epoxy. Hasil uji tarik menunjukkan nanokomposit yang terbentuk memiliki perilaku yang sama dengan komposit particulate epoxy, yaitu tensile strength yang mengalami penurunan seiring dengan penambahan komposisi clay. Hasil uji tekan dan kekerasan masing-masing menunjukkan yield compression strength yang tidak mengalami perubahan dan kekerasan mengalami sedikit peningkatan, yang tidak tergantung pada komposisi clay, seiring dengan penambahan komposisi clay.

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In this observation, clay-epoxy nanocomposites using Nanomer I30E organo clay, DER 331 epoxy resin and Versamid 125 curing agent were synthesized with an in-situ polimerization method. As comparison, fiberglass-epoxy composites using commercial fiber glass and the same epoxy resin and curing agent were synthesized with wet laminating method.

Characterization of internal structure and fracture morphology, using XRD (X-Ray Diffraction) and SEM (Scanning Electron Microscope) respectively, showed that nanocomposites had been successfully synthesized. Nanocomposites owned an exfoliated structure at clay composition <7.34 (% weight) and a mixture of exfoliated and intercalated structure at clay composition >7.34 (% weight). The nanocomposite with clay composition 2.10 (% weight) consisted of epoxy fase and clay agglomerates fase and owned cone shape fracture markings.

The results of tensile, compression and hardness testings showed that nanocomposites, synthesized using DM (Direct Mixing) dispersion technique, was found not suitable for structural application in aircraft replacing fiberglass-epoxy composite. The result of tensile testing showed nanocomposite formed owned similar behavior to particulateepoxy composite, where the tensile strength experienced decrease as clay composition was increased. The results of compression and hardness testings showed that yield compression strength didn’t experience change and hardness experienced few increases, which was not affected by clay’s composition, as clay's composition increased."

"Telah dilakukan penelitian untuk membuat material komposit dengan menggunakan poxy sebagai matriks dan woven roving E-Glass sebagai fiber. Pembuatan material enggunakan metode Vacuum Assisted Resin Infussion (VARI). Material dibuat dengan struktur serat terjalin 0°, 45°, dan -45° yang disusun sebanyak tujuh lapis. Uji tarik dilakukan untuk mengukur kekuatan mekanik material dan membandingkannya dengan hasil perhitungan menggunakan MATLAB 7.0.1. Pengujian dilanjutkan dengan penyinaran ultraviolet-A pada panjang gelombang 340nm yang lama penyinarannya divariasikan selama 10 jam, 20 jam, dan 30 jam. Kemudian, dilakukan kembali uji tarik dan didapatkan penurunan kuat tarik maksimum sebesar 28,22% sesudah penyinaran 30 jam, sedangkan modulus elastisitas relatif tidak berubah. Kerusakan yang terjadi akibat penyinaran pada ermukaan fiber dan matriks dilihat dengan menggunakan Scanning Electron Microscope (SEM).

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An experiment to make composites using epoxy as a matrix and woven roving E-Glass as a fiber was produced by a Vacuum Assisted Resin Infusion (VARI) method. The laminate systems consisted of seven woven fiber laminas with a pattern of 0°, 45°, and -45° degrees of orientation. Tensile properties of composites were obtained and compared with the result of MATLAB 7.0.1 program calculation The specimens were exposed by an ultraviolet-A (λ=340nm) with exposure period of 10, 20, and 30 hours The environmental tested specimens were followed by tensile test. The Ultimate Tensile Stress (UTS) of the composite decreased by 28,22% after 30 hours exposure. However, there was no reduction in the stiffness values. The Failure surfaces of specimen were observed using Scanning Electron Microscope. Failure was dominated with matrix rupture in transverse direction. "

"Nanokomposit polimer muncul sebagai kelas baru dari material dan telah banyak penelitian yang dilakukan sejak dua dekade lalu. Pada penelitian ini, clay komersial dari Indonesia, yaitu Bentone SD1, digunakan sebagai filler ke dalam polimer. Nanokomposit polypropylene-bentone SD1 (PP-SD1) telah berhasil dibuat dengan menggunakan metode melt intercalation. PP dan clay bentone dicampur dengan maleic anhydride (MA) dan inisiator diphenylamine GR (DPA) dalam proses peleburan untuk kemudian dicetak menggunakan hot press machine. Struktur material dikarakterisasi menggunakan X-Ray Diffraction (XRD) dan Transmission Electron Microscopy (TEM). Difraktogram XRD dan citra TEM memperlihatkan adanya interaksi antara organoclay dan matriks PP yang ditunjukkan dengan adanya struktur interkalasi pada nanokomposit. Dispersi clay pada matriks PP memberikan penguatan mekanik. Penambahan filler inorganik ini juga mempengaruhi sifat termal material, salah satunya sifat Heat Deflection Temperature (HDT). Pada penelitian ini, penurunan HDT pada nanokomposit dipengaruhi oleh parameter selama proses pembentukan nanokomposit.

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Polymer nanocomposites have emerged as a new class in material and a lot of research have done since two decades ago. In this research, a commercial clay from Indonesia, Bentone SD1, is used as a filler into a polymer. Polypropylenebentone SD1 (PP-SD1) nanocomposites were successfully prepared by a melt intercalation method. Polypropylene and bentone clay were modified with maleic anhydride (MA) and diphenylamine GR (DPA) initiator in a melting process, and then cast using a hot press machine. The structure of the materials was characterized using X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). XRD diffractogram and TEM images show that there was an interaction between organoclay and matrix PP which indicates an intercalation process in nanocomposites. Dispersion of clay in PP matrix provides mechanical reinforcement. Insertion inorganic fillers influence thermal properties, which one of the properties is the Heat Deflection Temperature (HDT). In this research, the HDT of the nanocomposites decreased and this was affected by the processing parameters used in the nanocomposite production."

"Biocomposite fiberboards using thermoplastic adhesive polymer white glue polyvinyl acetate and two types of natural fibers, rice straw and coir fibers, were made by vacuum bag moulding. The influences of fiber loading on the biocomposite?s tensile and behavior to water properties were investigated. Prior to the fabrication of the biocomposite the natural fibers were treated using the the alkali process by soaking the fibers in NaOH 5%. Three kind of fiber board were fabricated, a biocomposite with a variation of rice straw fiber loading, a biocomposite with a mixture of 50% rice straw and 50% coir whose fiber loading was also varied, and last a biocompsite with a 30% fiber loading mixture with a variation of coir fiber loading. The biocomposites fabricated had a gradual increase of tensile strength to an optimum fiber loading which after drops with the increase of fiber loading. Rice straw based composites had an optimum fiber loading of 30% percent and the the composite with a mixture of 50% rice straw and 50% coir dah an optimum fiber loading of 35%. The increase of fiber loading also increase the water content and the water absorption for all biocomposites fabricated. The study showed that rice straw and coir fibers may not work well with PVAc as reinforcing filler but showed similar trends when varying the fiber loading with other using natural fibers."

"Jerami padi dan ampas tebu merupakan limbah alam yang berpotensi untuk dijadikan papan serat. Polivinil asetat sebagai perekat dipilih karena termasuk polimer yang tidak terlalu mahal sehingga memungkinkan untuk membuat papan hibrida serat jerami padi - ampas tebu yang murah dan juga ramah lingkungan. Perlakuan kimia diterapkan pada kedua serat untuk memperbaiki mutu serat jerami padi dan ampas tebu sebelum dijadikan penguat pada papan hibrida.Penelitian ini bertujuan mengetahui komposisi terbaik papan jerami berbasis lem putih PVAc dan pengaruh penambahan ampas tebu dalam papan jerami padi, untuk mendapatkan komposisi terbaik juga mendapatkan sifat fisis dan mekanik terbaik. Komposisi optimal papan serat jerami padi sebesar 30 wt% menghasilkan kekuatan tarik sebesar 4.8 MPa sedangkan komposisi optimal papan hibrid jerami padi-ampas tebu adalah komposisi 15 wt% jerami padi, 15 wt% ampas tebu dan 70 wt% PVAc menghasilkan kekuatan tarik sebesar 3.7 MPa. Rata- rata kerapatan yang didapatkan pada papan hibrida adalah 0.75 gr/cm3 dengan kadar air 10% dan daya serap air mendekati 100%. Sifat mekanik dan sifat fisis papan hibrida yang tidak terlalu baik dikarenakan perekat yang digunakan mempunyai kuat tarik lemah, viskositas tinggi dan larut dalam air.

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Rice straw and bagasse are natural waste materials that have the potential to be used as fiber boards. Polyvinyl acetate adhesives have been employed because it is relatively economical and this is possible to produce relatively cheap and eco-friendly rice straw-bagasse hybrid boards. Chemical treatment applied to improve the quality of rice straw and bagasse prior the rice straw ? bagasse hybrid board production.This study aimed to determine the optimum composition of rice straw - PVAC white glue boards and the effects of bagasse addition to rice straw boards in order to achieve the optimum composition that provides the best physical and mechanical properties. Optimal composition of rice straw boards was in 30 wt% rice straw that provide a tensile strength of 4.8 MPa, while the optimal composition of hybrid boards is 15 wt% rice straw, 15 wt% bagasse and 70 wt% PVAc resulted a tensile strength of 3.7 MPa. Average density obtained on the hybrid fiber board was 0.75 gr/cm3 with 10 % moisture content and close to 100 % of water absorption. The mechanical and physical properties of these hybrid boards were not very good due to the adhesive used that had a low tensile strength, high viscosity and high water solubility."