Hasil Pencarian  ::  Simpan CSV :: Kembali

"ABSTRAKDengan perkembangan yang pesat dalam dunia industri, penggunaan komposit yang berbasis polipropilen semakin banyak digunakan. Namun, penggunaan komposit berbasis polimer menyebabkan peningkatan jumlah polusi dikarenakan waktu penguraian polipropilen yang lama. Serat alam, salah satunya serat sorgum mulai dilirik untuk dijadikan penguat dalam komposit berbasis polipropilen untuk menciptakan suatu komposit yang ramah lingkungan. Masalah utama dalam proses ini adalah, perbedaan sifat kelarutan yang tinggi antara serat sorgum dan Polipropilen. Metode alkalinasi-termal dipilih dalam proses preparasi serat untuk menciptakan serat yang aman bagi lingkungan dan memiliki kompatibilitas tinggi dengan polipropilen. Dalam penelitian ini akan dilihat pengaruh dari waktu pencampuran dan temperatur dalam proses pencampuran Polipropilen dengan serat sorgum. Pada penelitian ini akan dikaji sifat mekanik dan morfologi dari komposit yang terbentuk dan mencari waktu dan temperatur pencampuran yang optimum. Variasi waktu pencampuran dalam penilitian ini adalah 5 menit, 7,5 menit dan 10 menit. Sedangkan variasi temperatur proses adalah 160°C, 170°C dan 180°C. Pada penelitian didapatkan Waktu dan temperatur pencampuran yang optimum adalah 170°C selama 10 menit dengan nilai kekuatan tarik 22,77 MPa. Dimana bentuk morfologi pada produk komposit tersebut juga lebih bagus dibandingkan variabel lainnya karena sedikitnya fenomena fiber pull-out dan void yang terjadi pada produk komposit tersebut dibandingkan variabel lainnya.

---

ABSTRACTWith the rapid development in the industrial world, the use of polypropylene-based composites is increasingly being used. However, the use of polymer-based composites causes an increase in the amount of pollution due to the long decomposition time of polypropylene. Natural fibers, one of which is sorghum fiber, is starting to be used as an amplifier in polypropylene-based composites to create an environmentally friendly composite. The main problem in this process is the difference in the high solubility between sorghum and polypropylene fibers. The thermal-alkalination method was chosen in the fiber preparation process to create fibers that are environmentally safe and have high compatibility with polypropylene. In this study, the effect of mixing time and temperature on the mixing process of Polypropylene with sorghum fiber will be seen. In this study the mechanical and morphological properties of the composites will be examined and find the optimum mixing time and temperature. The variation of mixing time in this study is 5 minutes, 7.5 minutes and 10 minutes. While the process temperature variations are 160°C, 170°C and 180°C. In this study, the optimum mixing time and temperature was 170°C for 10 minutes with a tensile strength of 22.77 MPa. Where the morphology of composite products is also better than other variables due to the small number of fiber pull-out phenomena and voids that occur in these composite products compared to other variables."

"Plastik merupakan material yang mengalami perkembangan pesat 30 tahun terakhir ini. Namun sifatnya yang kurang kuat untuk aplikasi tertentu mengharuskan plastik dibuat menjadi komposit. Berbagai penguat sintetis tersedia seperti serat kaca namun harga serat kaca yang mahal dan sifatnya yang tidak ramah lingkungan membuat penggunaan material yang lebih murah dan ramah lingkungan sangat digencarkan. Komposit matriks polimer dengan penguat serat alam atau natural fiber reinforced polymer composites (NFRPC), sering hanya disebut natural fiber composites (NFC) menjadi solusinya. Dalam penelitian ini digunakan serat alam sorgum yang berasal dari dalam negeri dan bagian yang digunakan merupakan produk sampingan dari tanaman sorgum. Proses preparasi serat sorgum diperlukan untuk meningkatkan kompatibilitasnya dengan matriks polipropilen (PP). Alkalinisasi-termal menjadi metode yang dipakai dalam melakukan preparasi serat dan hasilnya setelah dilakukan proses ini serat memiliki mekanisme mechanical bonding (interlocking) dengan PP. Kemudian pengaruh temperatur pencampuran PP dan sorgum dengan variasi 160°C, 170°C, 180°C, serta komposisi serat dengan variasi 5%, 10%, dan 15% dipelajari perilaku mekanis dan morfologinya. Hasil yang didapatkan variasi yang optimum yaitu pada temperatur pencampuran 170°C dan komposisi serat 15% memiliki kekuatan tarik mencapai 20,2 MPa dan modulus elastis 547 MPa serta temperatur pencampuran 170°C dan komposisi serat 5% memiliki elongasi 36,4 MPa.

---

Plastic is a material that has experienced rapid development in the last 30 years. But its nature is less strong for certain applications, requiring plastic to be made into composites. Various synthetic reinforcements are available such as glass fiber but the expensive price of glass fiber and its environmentally unfriendly nature making the usage of cheaper and environmentally friendly materials highly intensified. Polymer matrix composites with natural fiber reinforced polymer composites (NFRPC), often just called natural fiber composites (NFC), are the solution.

In this study, natural sorghum fibers originating from within the country were used and the used parts were by-products of sorghum plants. The preparation process of sorghum fibers is needed to improve its compatibility with the polypropylene (PP) matrix. Thermal-alkalinization is the method used in conducting fiber preparation and the results after this process the fibers have mechanical bonding (interlocking) mechanism with PP. Then the effect of PP and sorghum mixing temperature with variations of 160°C, 170°C, 180°C, and fiber composition with variations of 5%, 10%, and 15% on mechanical and morphological behavior were studied. The optimum result is obtained at mixing temperature of 170°C and 15% fiber composition that have tensile strength reaching 20,2 MPa and elastic modulus of 547 MPa also at mixing temperature of 170°C and 5% fiber composition have elongation of 36,4%."

"Peningkatan perhatian global mengenai masalah lingkungan dan sustainability terkait dengan pelestarian sumber daya alam tak terbarukan telah mendorong upaya untuk mengembangkan bahan dan produk ramah lingkungan baru berdasarkan sumber daya alam yang terbarukan. Serat sorgum memiliki potensi untuk dijadikan penguat komposit karena memiliki sifat mekanis yang baik, ramah lingkungan, murah. Pada studi ini komposit polipropilen-sorgum dibuat dengan rheomix pada temperatur 160Oc, kecepatan 50 rpm dengan variasi komposisi serat 5%, 10%, 15% serta variasi waktu pencampuran 5 menit, 7.5 menit, dan 10 menit. Sifat mekanis komposit polipropilen-sorgum dipengaruhi mechanical interlockpada interfaceserat dengan matriks polipropilen. Modifikasi alkalinasi-termal dengan NaOH 5% dan waktu kukus bertekanan selama 3 menit dilakukan untuk mengubah hidrofobisitas serat sorgum dan memperbaiki ikatan antara matriks polipropilen dengan serat sorgum. Diperoleh bahwa modulus young komposit polipropilen-sorgum menaik dengan penambahan serat dan penambahan waktu pencampuran, Ultimate Tensile Strength komposit polipropilen-sorgum menurun setelah melewati batas optimum komposisi serat dan menaik dengan penambahan waktu pencampuran. Sifat elastisitas komposit polipropilen-sorgum berkurang seiring penambahan komposisi serat dan penambahan waktu pencampuran. Hubungan antara variasi komposisi serat dan waktu pencampuran dianalisa untuk mengevaluasi pengaruhnya pada performa penguatan komposit polipropilen oleh serat sorgum. Tujuan penelitian adalah untuk mendapatkan variabel komposisiserat dan waktu pencampuran yang optimum untuk memperoleh sifat mekanis terbaik.

---

Increasing global concern to environmental issues and sustainability related to preservation of non-renewable natural resources has encouraged research to development environmentally friendly materials and products based on renewable natural resources. Sorghum fiber has the potential to be a composite reinforcement because it has good mechanical properties, is environmentally friendly, inexpensive. In this study polypropylene-sorghum composites were made with Rheomix at a temperature of 160Oc, speed of 50 rpm with variations in fiber fraction of 5%, 10%, 15% and variations in mixing time of 5 minutes, 7.5 minutes, and 10 minutes. The mechanical properties of polypropylene-sorghum composites are determined by mechanical interlocks on fiber interfaces with the polypropylene matrix. Alkalination-thermal modification with 5% NaOH and pressurized steam for 3 minutes was carried out to change the hydrophobicity of sorghum fibers and improve the bond between the polypropylene matrix and sorghum fiber.

It was found that the young modulus of polypropylene-sorghum composite increased with the addition of fiber and the addition of mixing time, the Ultimate Tensile Strength polypropylene-sorghum composite decreased after crossing the optimum fiber fraction boundary and increasing with the addition of mixing time. The elasticity of polypropylene-sorghum composites decreases with the addition of fiber fraction and the addition of mixing time. The relationship between variations in fiber fraction and mixing time was analyzed to evaluate their effect on the performance of composite reinforcement of polypropylene by sorghum fibers. The aim of the study was to obtain the optimal fiber fraction and mixing time to obtain the best mechanical properties."

"Masalah lingkungan khususnya tentang non degradable telah menjadi masalah serius, oleh karena itu diperlukan suatu solusi seperti menggunakan bahan alam sebagai penganti bahan bakar atau polimer ramah lingkungan. Serat tanaman sorgum atau Sorgum bicolor menjadi salah satu sumber yang sangat potensial untuk diolah menjadi bahan baku komposit. Tantangan utama menggunakan serat alam sebagai penguat adalah mudah menyerap air atau bersifat hidrofilik. Akibatnya ikatan antarmuka antara serat dan matriks menjadi lemah. Dengan menghilangkan kandungan lignin dan hemiselulosa yang menyelimuti serat sehingga dihasilkan serat nanokristalin selulosa yang memiliki kompatibilitas yang baik dengan matriks. Untuk mengatasinya dilakukan berbagai perlakuan salah satunya perlakuan hidrothermal, jenis perlakuan ini lebih ramah lingkungan dari proses lainya karena hanya air yang digunakan sebagai reagen, relatif murah, mudah dan sedikit by produk. Metode yang digunakan meliputi perebusan selama 5 menit dan dilakukan masak bertekanan selama 10 menit dan 15 menit. Pengujian yang dilakukan adalah pengujian SEM untuk melihat kompatibilitas antara serat dan polimer. Pengujian thermal dilakukan untuk melihat suhu kristalinitas dan suhu leleh dari komposit. Pengujian tarik dilakukan untuk melihat kekuatan mekanik dari komposit. Kondisi komposit paling optimum dari pengujian adalah pada proses pressure cooking pada 10 menit dan fiber load 5%.

---

Environmental problems especially about non degradable, have become a serious problem, therefore a solution such as using natural materials as fuel or ecofriendly polymers is required. Sorghum fiber or Sorghum bicolor become one of the most potential sources to be processed into composite raw materials. The main challenge of using natural fibers as reinforcement is the easy to absorb water or hydrophilic. Consequently the interface bond between the fiber and the matrix becomes weak. Removing the lignin and hemicellulose contents that envelop the fibers to produce nanocrystalline cellulose that have good compatibility with the matrix.

To overcome this a variety of treatment was done, one of those was the hydrothermal treatment, this treatment is more environmentally friendly than other processes because only water is used as reagents, relatively cheap, easy and little by product. The method used includes boiling for 5 minutes and pressure cooking for 10 minutes and 15 minutes. The SEM is done to see compatibility between fiber and polymer. Thermal test is performed to see the temperature of crystallinity and the melting temperature of the composite. Tensile test is performed to see the mechanical strength of the composite. The optimum conditions composite at the pressure cooking process at 10 minutes and fiber load 5%."

"Pada penelitian ini dibuat komposit menggunakan polipropilena sebagai matriks dan serat sorghum sebagai penguat. Namun, polipropilena dan serat sorghum memiliki permasalahan yaitu sifat permukaan antara keduanya berbeda. Untuk memperbaiki sifat permukaan serat sorghum, perlu dilakukan modifikasi permukaan dengan perlakuan kimiawi seperti alkalinisasi, pemutihan dan hidrolisis asam. Proses alkalinisasi dilakukan menggunakan larutan NaOH 10% selama 2 jam. Proses pemutihan dilakukan dengan larutan NaClO2 1,7% selama 4 jam dan proses hidrolisis asam dilakukan dengan larutan H2SO4 25% selama 1 jam. Kemudian dilakukan proses hot melt mixing untuk dilakukan pencampuran antara PP dan serat sorghum. Pengaruh komposisi serat dan modifikasi serat sorghum menjadi fokus pada penelitian ini.Hasil penelitian menunjukan bahwa kristalinitas, kompatibilitas dan kuat tarik komposit berpenguat serat perlakuan pemutihan lebih baik dibandingkan komposit berpenguat serat tanpa perlakuan. Sedangkan penambahan komposisi 5% & 10% serat perlakuan hidrolisis asam mengalami penurunan kekuatan tarik dibandingkan kuat tarik PP.

---

In this research composites was made using polypropylene as matrix and sorghum fibers as reinforcement. However, polypropylene and sorghum fiber has a problem that have different surface properties. To improve the surface properties of the sorghum fiber, surface modification needs to be done by chemical treatment such as alkalinization, bleaching and acid hydrolysis. alkalinization process is done by 10% NaOH solution for 2 hours. The bleaching process is done by 1,7% NaClO2 solution for 4 hours and the process of acid hydrolysis carried out by 25% H2SO4 solution for 1 hour. Then do the hot melt mixing process to do the mixing between the PP and fiber sorghum. The influence of fiber composition and modification of sorghum fiber on manufacture of PP/sorghum composites to be focused on this research.

The results showed that the crystallinity, compatibility and tensile strength of composite reinforced by bleaching treatment fiber is better than the composite reinforced by untreated fiber. While, the addition of the composition by 5% and 10% fiber to acid hydrolysis treatment decreased the tensile strength than tensile strength of PP.

"

"[Pada penelitian ini, serat ijuk dihancurkan dan diayak ukuran 40 # setelah itu serat ijuk diberi perlakuan kimia dengan NaOH 2 % selama 1 jam, KMnO4 0,1 N selama 15 menit, dan NaClO 5 % selama 5 jam dengan tujuan mendapatkan selulosa kristalin. Setelah itu dilakukan proses pencampuran kering (hotmelt mixing) antara polipropilen dengan serat ijuk hasil perlakuan kimia dengan 7,5 % volum serat ijuk terhadap polipropilen dengan variabel temperatur 160°C, 165°C, dan 170°C dan variabel waktu pencampuran 15 menit dan 20 menit. Setelah itu dilakukan pengujian uji FTIR buat serat, sedangan buat komposit adalah uji tarik, uji STA, uji XRD, dan uji FE-SEM hal ini dilakukan untuk mendapatkan sifat kristalinitas dan mekanik dari komposit polipropilen ini. Hasil penelitian menunjukkan bahwa serat ijuk hasil perlakuaan lebih kristalin dari pada serat ijuk tanpa perlakukan, polipropilen dengan serat ijuk hasil perlakuaan kimia cukup kompatibel terhadap polipropilen, dari penelitian didapatkan sifat kristalinitas terbaik pada variabel 165°C selama 20 menit. Dan yang memiliki sifat kekuatan tarik paling baik adalah variabel 170°C selama 20 menit, sedangkan yang memiliki % elongasi paling baik adalah dengan variabel 160°C 20 menit.

---

In this work, palm fiber crushed and sieved size 40 # after the palm fiber chemically treated with 2% NaOH for 1 hour, 0.1 N KMnO4 for 15 minutes, and 5% NaClO for 5 hours in order to obtain crystalline cellulose. Once that is done the dry mixing (hotmelt mixing) between polypropylene and palm fiber chemical treatment results with 7.5% volume of the palm fiber and polypropylene with a variable temperature of 160°C, 165°C and 170°C and a variable time mixing 15 minutes and 20 minutes. After it was examined FTIR test for fiber, while the composite is made tensile test, STA test, XRD test and FE-SEM test this is done to obtain crystallinity and mechanical properties of polypropylene composites this. The results show that fiber perlakuaan results more crystalline fibers than untreated palm fiber, polypropylene and palm fiber chemistry results treatment compatible enough to polypropylene, crystallinity of the research showed the best properties on the variable 165 ° C for 20 minutes. And who has the most excellent tensile strength properties are variable 170 ° C for 20 minutes, while the best of % elongation is at a variable 160 ° C 20 minutes.;In this work, palm fiber crushed and sieved size 40 # after the palm fiber chemically treated with 2% NaOH for 1 hour, 0.1 N KMnO4 for 15 minutes, and 5% NaClO for 5 hours in order to obtain crystalline cellulose. Once that is done the dry mixing (hotmelt mixing) between polypropylene and palm fiber chemical treatment results with 7.5% volume of the palm fiber and polypropylene with a variable temperature of 160°C, 165°C and 170°C and a variable time mixing 15 minutes and 20 minutes. After it was examined FTIR test for fiber, while the composite is made tensile test, STA test, XRD test and FE-SEM test this is done to obtain crystallinity and mechanical properties of polypropylene composites this. The results show that fiber perlakuaan results more crystalline fibers than untreated palm fiber, polypropylene and palm fiber chemistry results treatment compatible enough to polypropylene, crystallinity of the research showed the best properties on the variable 165 ° C for 20 minutes. And who has the most excellent tensile strength properties are variable 170 ° C for 20 minutes, while the best of % elongation is at a variable 160 ° C 20 minutes.;In this work, palm fiber crushed and sieved size 40 # after the palm fiber chemically treated with 2% NaOH for 1 hour, 0.1 N KMnO4 for 15 minutes, and 5% NaClO for 5 hours in order to obtain crystalline cellulose. Once that is done the dry mixing (hotmelt mixing) between polypropylene and palm fiber chemical treatment results with 7.5% volume of the palm fiber and polypropylene with a variable temperature of 160°C, 165°C and 170°C and a variable time mixing 15 minutes and 20 minutes. After it was examined FTIR test for fiber, while the composite is made tensile test, STA test, XRD test and FE-SEM test this is done to obtain crystallinity and mechanical properties of polypropylene composites this. The results show that fiber perlakuaan results more crystalline fibers than untreated palm fiber, polypropylene and palm fiber chemistry results treatment compatible enough to polypropylene, crystallinity of the research showed the best properties on the variable 165 ° C for 20 minutes. And who has the most excellent tensile strength properties are variable 170 ° C for 20 minutes, while the best of % elongation is at a variable 160 ° C 20 minutes.;In this work, palm fiber crushed and sieved size 40 # after the palm fiber chemically treated with 2% NaOH for 1 hour, 0.1 N KMnO4 for 15 minutes, and 5% NaClO for 5 hours in order to obtain crystalline cellulose. Once that is done the dry mixing (hotmelt mixing) between polypropylene and palm fiber chemical treatment results with 7.5% volume of the palm fiber and polypropylene with a variable temperature of 160°C, 165°C and 170°C and a variable time mixing 15 minutes and 20 minutes. After it was examined FTIR test for fiber, while the composite is made tensile test, STA test, XRD test and FE-SEM test this is done to obtain crystallinity and mechanical properties of polypropylene composites this. The results show that fiber perlakuaan results more crystalline fibers than untreated palm fiber, polypropylene and palm fiber chemistry results treatment compatible enough to polypropylene, crystallinity of the research showed the best properties on the variable 165 ° C for 20 minutes. And who has the most excellent tensile strength properties are variable 170 ° C for 20 minutes, while the best of % elongation is at a variable 160 ° C 20 minutes.;In this work, palm fiber crushed and sieved size 40 # after the palm fiber chemically treated with 2% NaOH for 1 hour, 0.1 N KMnO4 for 15 minutes, and 5% NaClO for 5 hours in order to obtain crystalline cellulose. Once that is done the dry mixing (hotmelt mixing) between polypropylene and palm fiber chemical treatment results with 7.5% volume of the palm fiber and polypropylene with a variable temperature of 160°C, 165°C and 170°C and a variable time mixing 15 minutes and 20 minutes. After it was examined FTIR test for fiber, while the composite is made tensile test, STA test, XRD test and FE-SEM test this is done to obtain crystallinity and mechanical properties of polypropylene composites this. The results show that fiber perlakuaan results more crystalline fibers than untreated palm fiber, polypropylene and palm fiber chemistry results treatment compatible enough to polypropylene, crystallinity of the research showed the best properties on the variable 165 ° C for 20 minutes. And who has the most excellent tensile strength properties are variable 170 ° C for 20 minutes, while the best of % elongation is at a variable 160 ° C 20 minutes., In this work, palm fiber crushed and sieved size 40 # after the palm fiber chemically treated with 2% NaOH for 1 hour, 0.1 N KMnO4 for 15 minutes, and 5% NaClO for 5 hours in order to obtain crystalline cellulose. Once that is done the dry mixing (hotmelt mixing) between polypropylene and palm fiber chemical treatment results with 7.5% volume of the palm fiber and polypropylene with a variable temperature of 160°C, 165°C and 170°C and a variable time mixing 15 minutes and 20 minutes. After it was examined FTIR test for fiber, while the composite is made tensile test, STA test, XRD test and FE-SEM test this is done to obtain crystallinity and mechanical properties of polypropylene composites this. The results show that fiber perlakuaan results more crystalline fibers than untreated palm fiber, polypropylene and palm fiber chemistry results treatment compatible enough to polypropylene, crystallinity of the research showed the best properties on the variable 165 ° C for 20 minutes. And who has the most excellent tensile strength properties are variable 170 ° C for 20 minutes, while the best of % elongation is at a variable 160 ° C 20 minutes.]"

"Komposit ramah lingkungan merupakan komposit dengan salah satu atau semua unsur penyusunnya merupakan bahan alam. Indonesia dengan keragaman hayati menghasilkan berbagai jenis serat alam sebagai penguat, salah satunya serat daun nanas. Penelitian ini bertujuan untuk mengetahui pengaruh kandungan serat daun nanas Subang pada ketahanan impak dan kekerasan dari komposit polipropilena/serat daun nanas Subang. Perlakuan alkali dilakukan pada serat daun nanas Subang dan komposit difabrikasi dengan metode hot press. Hasil pengukuran densitas, papan komposit dikelompokkan dalam kategori Papan Serat Kerapatan Tinggi (PSKT) berdasarkan SNI 01-4449-2006. Hasil uji bakar, impak, dan kekerasan menunjukkan komposit dengan fraksi berat serat daun nanas Subang 40 wt.% adalah komposit terbaik dengan nilai masing masing 14 mm/menit, (31,6 ± 4,5) J/cm2, dan (60,5 ± 2,01) HD. Hasil pengamatan menunjukkan adanya hasil bakar dan fiber pull out."

"ABSTRAKBambu sebagai salah satu serat alam yang ada di Indonesia berpotensi menjadi penguat pada komposit yang ramah lingkungan. Penelitian ini dilakukan untuk menentukan jenis komposit dan kuat lengkung dari komposit polipropilena/serat Bambu Tali (PP/SBT) sesuai dengan SNI 01-4449-2006 untuk papan serat dan kekeraannya. Serat Bambu Tali diberi perlakuan alkali sebelum dijadikan penguat komposit. Single Fiber Test dan analisa FTIR dilakukan pada serat Bambu Tali sebelum dan sesudah proses alkalisasi. Fabrikasi komposit menggunakan mesin ekstruder dengan variasi fraksi berat serat Bambu Tali 10wt%, 20wt%, dan 30wt%, dengan ukuran serat 0.5 mm. Uji lengkung dan kekerasan dilakukan pada komposit dan polipropilena murni, dan pengamatan Scanning Electron Microscope (SEM) dilakukan pada permukaan patahan uji lengkung. Hasil uji lengkung dan densitas menunjukkan bahwa komposit PP/SBT merupakan tipe Papan Serat Kerapatan Tinggi (PSKT) T1, dengan modulus lengkung dan kuat lengkung terbaik pada PP/SBT 30wt% masing-masing yaitu (79,01±4,47) GPa dan (36,97±3,03) MPa. Nilai ini meningkat 15,5% dan 25,6% dari polipropilena murni. Nilai uji kekerasan terbaik pada komposit PP/SBT 30wt% yaitu (61,86±0,67) HD yang meningkat 26% dari nilai kekerasan polipropilena murni. Hasil pengamatan SEM terlihat patahan serat terjadi pada permukaan patahan uji lengkung.

---

ABSTRACT

Bamboo as one of the natural fibers in Indonesia has the potential to become an environmental friendly composite reinforcement. This study was conducted to determine the density of composite and bending properties of polypropylene/Tali Bamboo fiber (PP/TBF) composites in accordance with SNI 01-4449-2006 for fiberboard and their hardness. Tali Bamboo Fiber was treated with alkali before being fabricated. Single Fiber Test and FTIR analysis were conducted on Tali Bamboo fibers before and after the alkalization process. Composites were fabricated using an extruder machine with variations in the weight fraction of Tali Bamboo fiber i.e 10wt%, 20wt%, and 30wt%, with a fiber size of 0.5 mm. Bending and hardness tests were carried for composites and pristine polypropylene ; fracture surfaces after bending test were ensured using Scanning Electron Microscope (SEM). The density and bending test results showed that all PP/TBF composites were categorized as Papan Serat Kerapatan Tinggi (PSKT) T1 type. PP/TBF30 composites had the highest bending modulus and strength of (79.01±4.47) GPa and (36.97±3.03) MPa respectively. These values increased 15.5% and 25.6% compared to the pristine polypropylene. The highest hardness value belong to PP/TBF30 i.e (61,86±0.67) HD, in which increased 26% from the value of pristine polypropylene hardness. SEM observations showed that fiber failure occurred on the fracture surfaces after bending test.

"

"Peralihan penggunaan serat sintetis menjadi serat alam sebagai penguat pada material komposit sudah banyak dilakukan. Serat alam sebagai penguat pada komposit dapat mengurangi polusi lingkungan dan ketergantungan penggunaan serat sintetis sehingga material komposit memiliki sifat yang ramah lingkungan. Tujuan dari penelitian ini yaitu untuk memperoleh nilai sifat mekanik berupa regangan, kuat tarik dan modulus elastisitas menggunakan Rule of Mixture dan teori specially orthotropic lamina dari model komposit polipropilena diperkuat serat daun nanas Subang unidirectional. Serat yang digunakan dalam penelitian ini adalah serat kenaf, serat tebu, serat alfa, dan serat rami dengan fraksi volume serat 22 %. Hasil perhitungan memperlihatkan nilai regangan longitudinal terkecil didapat model komposit polipropilena/ serat rami sebesar 0,89 %. Untuk regangan transversal dan geser terkecil dimilliki oleh model komposit polipropilena berpenguat serat alfa sebesar 1,2 % dan 1,3 %. Kelima komposit polipropilena berpenguat 22 vol% serat alam digolongkan sebagai papan serat kerapatan tinggi berdasarkan SNI 01-4449-2006 mengenai papan serat.

---

The replacement of synthetic fibers into natural fibers as reinforcements in composite materials has been carried out. Natural fiber as a reinforcement in composites can reduce environmental pollution and the dependence on the use of synthetic fibers, so that composite materials can be environmentally friendly materials. The purpose of this study is to predict the value of mechanical properties in the form of strain, tensile strength and modulus of elasticity using the Rule of Mixture and the specially orthotropic lamina theory of the polypropylene composite model reinforced by unidirectional Subang pineapple leaf fiber. The fiber used in this research is kenaf fiber, sugar cane fiber, alfa fiber, and ramie fiber with 22% fiber volume fraction. The calculation results show the smallest longitudinal strain value obtained by polypropylene/hemp fiber composite models of 0.89%. For the smallest transversal and shear strain have an alfa fiber reinforced polypropylene composite model of 1.2% and 1.3%. The five polypropylene composites containing 22 vol% natural fibers are classified as high density fiberboard based on SNI 01-4449-2006 concerning fiberboard."