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"Fenomena kristalisasi dari material polipropilena kopolimer impak IPC dimodelkan secara non-isotermal dengan model kinetika Nakamura yang merupakan perluasan dari model kinetika isotermal Avrami. Teori Hoffman-Lauritzen digunakan di dalam kinetika Nakamura untuk menggambarkan kecepatan kristalisasi rata-rata sebagai fungsi dari temperatur. Beberapa parameter pada persamaan Hoffman-Lauritzen seperti konstanta nukleasi dan pre-exponential factor harus dikalibrasi terlebih dahulu dengan mengacu pada data differential scanning calorimetry DSC dari IPC murni. Hasil permodelan kemudian dibandingkan dengan data DSC dari hasil eksperimen IPC yang ditambahkan 5, 15, dan 25 serat kenaf dengan temperatur pencampuran 170oC dan waktu pencampuran 15 menit. Serat kenaf yang digunakan diberi perlakuan alkalinisasi dengan larutan NaOH 6 selama 8 jam. Penambahan konsentrasi serat kenaf memicu penurunan indeks Avrami n sampel dari n=3 menuju n=2. Indeks Avrami n=2 menunjukkan bahwa sampel mengalami kristalisasi dengan pertumbuhan secara 1-dimensi. Tetapi, terdapat beberapa perbedaan dari kurva kristalisasi antara hasil simulasi dan data eksperimen yang didapatkan. Perbedaan ini dapat disebabkan karena terjadinya fenomena secondary nucleation dan kurangnya masukan kalor yang diberikan pada saat proses pencampuran IPC dengan serat kenaf.

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The non isothermal crystallization phenomenon of impact polypropylene copolymer IPC has been modeled using the Nakamura equation model which is an extension of the Avrami equation. The theory of Hoffman Lauritzen is used inside the Nakamura kinetic model to describe the average crystallization rate as a function of temperature. Some parameters of Hoffman Lauritzen need to be calibrated first by considering the differential scanning calorimetry DSC data of pure IPC. We compared the model predictions with the DSC non isothermal crystallinity results of IPC with additions of 5, 15, and 25 kenaf fiber. The mixing temperature and mixing time in this experiments were 170oC and 15 minutes, respectively. The kenaf fiber was pre treated with 6 NaOH for 8 hours. The addition of kenaf fiber showed a decrease in Avrami index of the sample from n 3 to n 2. Indicating that the crystallization process was experiencing a 1 dimensional growth. However, there were several discrepancies between the model predictions and experimental results. The phenomenon of secondary nucleation and the lack of heat input in IPC mixing process with the kenaf fiber could cause these differences."

"Fokus pada penelitian ini adalah mensimulasikan perilaku kristalisasi polipropilena kopolimer impak (IPC) setelah penambahan serat ijuk dan kenaf yang telah dimodifikasi sebanyak 5% fraksi massa. Alkalinisasi dan pemutihan dilakukan untuk memodifikasi serat. Tujuan dari proses tersebut adalah menghilangkan komponen hidrofilik pada serat. Peristiwa kristalisasi dapat dimodelkan secara non-isotermal dengan model kinetika Nakamura. Model tersebut merupakan pengembangan dari model isotermal Avrami. Penambahan serat kenaf dapat menurunkan nilai indeks Avrami (n) sampel IPC mendekati n = 2. Nilai indeks Avrami n = 2 mengindikasikan bahwa sampel mengalami kristalisasi dengan pertumbuhan secara 1-dimensi searah dengan arah serat sehingga menghasilkan anisotropi pada produk akhir. Sedangkan penambahan serat kenaf justru menaikkan nilai indeks Avrami mendekati n = 4. Nilai tersebut menunjukkan bahwa kristalisasi pada sampel terjadi dengan pertumbuhan secara 3-dimensi dan menghasilkan isotropi pada produk akhir. Morfologi serat menyebabkan perbedaan tersebut. Perlakuan alkalinisasi dapat mengubah morfologi serat sehingga dapat mempengaruhi perilaku kristalisasi dari polipropilena kopolimer impak.

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The focus of this research is to simulate the crystallization behavior of impact polypropylene copolymer (IPC) after the addition of modified fibers and kenaf fibers by 5% mass fraction. Alkalinization and bleaching are carried out to modify the fiber. The aim of the process is to remove the hydrophilic component in the fiber. The crystallization event can be modeled non-isothermal with the Nakamura kinetics model. The model is a development of the Avrami isothermal model. The addition of kenaf fibers can reduce the value of the Avrami index (n) IPC samples close to n = 2.

The value of the Avrami index n = 2 indicates that the sample crystallizes with growth in 1-dimensional direction in the direction of the fiber so as to produce anisotropy in the final product. While the addition of kenaf fibers actually increases the value of the Avrami index to close to n = 4. The value indicates that crystallization in the sample occurs with 3-dimensional growth and produces isotropy in the final product. Fiber morphology causes this difference. The alkalinization treatment can change the morphology of the fiber so that it can influence the crystallization behavior of the impact copolymer polypropylene."

"Efek penambahan serat ijuk (Arenga Pinata) terhadap perilaku kristalisasi Polipropilena Kopolimer Impak (IPC) ditelaah menggunakan model kinetika Nakamura untuk solidifikasi non-isotermal. Model tersebut merupakan pengembangan dari model isotermal Avrami. Hasil permodelan kemudian dibandingkan dengan data DSC dari hasil eksperimen IPC yang ditambahkan 1%, dan 5% serat ijuk dengan temperatur pencampuran masing-masing 160 ^oC dan 165 o^C. Serat ijuk yang digunakan pada penilitian, sebelumnya telah diberi perlakuan alkalinisasi dengan larutan NaOH 6% selama 8 jam. Penambahan serat ijuk dapat menggeser nilai indeks Avrami (n) spesimen IPC yang pada kondisi murni memiliki nilai n=3. Penambahan serat ijuk sebesar 1% dan 5% fraksi masss pada suhu 160 ^oC dapat menurunkan nilai indeks Avrami masing-masing sampel menjadi 2.9268 dan 2.506. Nilai n yang mendekati 2 ini  menunjukan bahwa sampel cenderung mengalami pertumbuhan secara 1-dimensi dan menghasilkan struktur yang lebih kristalin Sedangkan penambahan serat ijuk sebesar 1% dan 5% pada suhu 160 ^oC menaikkan nilai indeks Avrami masing-masing menjadi 3.2726 dan 3.2489. Nilai n yang lebih besar dari 3 menunjukan arah pertumbuhan 2 dimensi dan menghasilkan struktur yang kurang kristalin.

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We use Nakamura kinetic model for non-isothermal solidification to investigate the effect on the addition of Arenga Pinata fiber to the crystallization behavior of impact polypropylene copolymer (IPC). We compared the model predictions with the DSC non-isothermal crystallinity results of IPC with additions of 1%, and 5% Arenga Pinata fiber each mixed  at 160 ^oC and 165 ^oC. The fiber used in this experiment was previously pre-treated with 6% NaOH for 8 hours. The addition of Arenga Pinata fiber shift the Avrami index of pure IPC from the original value of 3. The addition of 1% and 5% of fiber at 160 ^oC mixing temperature decrease the Avrami Index to 2.9268 dan 2.506 respectively. It is indicating that the crystallization process was experiencing a 1-dimensional growth and result in a more crystalline structure. However, the addition of fiber at 165 ^oC mixing temperature increase the Avrami Index to 3.2726 dan 3.2489 respectively. It is indicating that the crystallization process was experiencing a 2-dimensional growth and result in a less crystalline structure."

"ABSTRAKkomposit berpenguat serat alam dapat menjadi alternatif untuk menggantikan komposit berpenguat serat sintetis yang kurang ramah terhadap lingkungan. Serat dari tumbuhan kenaf adalah salah satu serat alam yang dapat dimanfaatkan sebagai pengganti penguat serat sintesis pada komposit. Tujuan dari penelitian ini adalah untuk mengetahui kuat lentur, daya serap air, dan kadar air pada komposit polipropilena berpenguat serat kenaf dengan variasi fraksi berat serat sesuai dengan SNI 01-4449-2006. Serat kenaf diberi perlakuan alkali sebelum digunakan sebagai penguat dengan cara direndam dalam larutan NaOH 5%. Komposit polipropilena/serat kenaf kemudian difabrikasi dengan mesin hot press. Fraksi berat serat yang digunakan pada penelitian adalah 30 wt%, 40 wt%, 50 wt%, dan sampel polipropilena murni juga difabrikasi sebagai pembanding. Komposit yang difabrikasi disebut sebagai papan serat dengan kerapatan tinggi menurut SNI karena memiliki nilai densitas 1,08 g/cc. Kuat lentur, daya serap air, dan kadar air terbaik dimiliki oleh komposit polipropilena/serat kenaf 30wt% dengan nilai masing-masing (4,77 ± 1,00) MPa, (3,61 ± 1,77) % dan (1,12 ± 0,34)%; dan nilai-nilai ini memenuhi Standard Nasional Indonesia (SNI) tentang papan serat.

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ABSTRACTNatural fiber reinforced composites can be an alternative to replace composites with synthetic fibers reinforcement that are less environmentally friendly. Kenaf fiber which is obtained from kenaf plant is one of natural fibers that can be used as a reinforcement in composites. The purpose of this research was to determine the flexural strength, water absorbent, and water content of polypropylene/kenaf fiber composites with variations of fiber weight fraction according to SNI 01-4449-2006. Kenaf fiber was treated by alkaline treatment before being used as a reinforcement by immersing kenaf fiver in NaOH 5% solution. Polypropylene/kenaf fiber composites were fabricated with compression moulding method using a hot press machine. Fiber weight fractions used in this research were 30 wt%, 40 wt%, 50 wt%, and pristine polypropylene samples were also fabricated as a comparison. Based on SNI, the fabricated composites was called Papan Serat Kerapatan Tinggi (PSKT) because the density value was 1,08 g/cc. The flexural strength, minimum water absorption and water content were found in polypropylene/kenaf fiber composite 30wt% with the value of (4,77 ± 1,00) MPa, (3,61 ± 1,77) % and (1,12 ± 0,34)% respectively and these values met the Fiber Board Indonesian National Standard (SNI)."

"ABSTRAKPenelitian ini fokus pada peningkatan sifat mekanis Polipropilena impak kopolimer (PP) dengan menggunakan serat ijuk yang telah dimodifikasi. Modifikasi serat ijuk dilakukan dengan menggunakan proses alkalinisasi dan pemutihan. Proses tersebut bertujuan untuk meningkatkan kristalinitas dan kompatibilitas serat ijuk terhadap matriks PP. Pembuatan komposit PP-ijuk dilakukan menggunakan metode pencampuran lelehan panas untuk selanjutnya di cetak sesuai spesifikasi sampel uji sifat mekanis. Proses pencampuran dilakukan selama 15 menit dan dipelajari dua variabel utama, yakni variasi kadar serat ijuk (1%, 3%, 5%) dan variasi temperatur pencampuran (160⁰C dan 165⁰C). Komposit yang terbentuk selanjutnya dilakukan pengujian STA dan UTM. Dari hasil percobaan dapat disimpulkan bahwa peningkatan sifat mekanis yang optimal didapatkan pada percobaan menggunakan serat ijuk 1% dan suhu pencampuran 160⁰C. pada sampel tersebut teramati penambahan nilai kuat tarik hampir mencapai 1 Mpa. Hasil percobaan mengindikasikan bahwa serat ijuk hasil modifikasi dapat digunakan sebagai filler untuk meningkatkan sifat mekanis PP. Kondisi utama yang paling mempengaruhi peran positif serat ijuk adalah distribusi dan dispersi.

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ABSTRACTThis research focused on the employment of modificated ?ijuk? fibers as fillers to improve the mechanical properties of polypropylene impact copolymer (PP). Ijuk fibers are processed through alkali treatment and bleaching. Those processes are intended to improve the crystalinity and compatibility of ?ijuk? fibers to matrix PP. Afterwards, PP-ijuk composite is made by using rheomixing and subsequently casted in satisfactory to meet the requirements as standard sample for tensile strength testing. Rheomixing was conducted for 15 minutes in different concentration of ?ijuk? fibers (1%, 3%, 5%) and temperature (160⁰C dan 165⁰C). STA and UTM were used to observe the properties of the composite. From the results, can be concluded that the optimal condition to improve the mechanical properties of PP is obtained in the condition of 1% ?ijuk? fibers and 160⁰C mixing temperature. These condition were successfully improved the tensile strength of PP by 1 Mpa. The experiments indicated that modificated ?ijuk? fibers can be used as filler to increase the mechanical properties of PP. Distribution and dispertion were attributed as the main factors which influenced the processes."

"[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.

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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.]"

"Polipropilena (PP) adalah polimer termoplastik yang digunakan dalam berbagai aplikasi. Proses kristalisasi adalah proses yang memiliki peranan penting dalam produksi PP. Penambahan nucleating agent yang berfungsi mempersingkat waktu induksi kristalisasi polimer tertentu, termasuk PP. Tujuan dari penelitian ini untuk menganalisis pengaruh penambahan microcrystalline cellulose (MCC) dan microfibrillated cellulose (MFC) sebagai aditif nucleating agent pada proses kristalisasi PP dan memperoleh persentase optimum yang dibandingkan terhadap Hyperform HPN-20E (HPN) sebagai nucleating agent komersial dan PP murni. MFC dibuat dengan alkalisasi, bleaching dan hidrolisis. MFC dan MCC dikarakterisasi dengan SEM dan XRD. Masing-masing dari MFC, MCC dan HPN dilakukan internal mixing dengan PP pwd dengan konsentrasi 0,10; 0,20; 0,40; 1,00 dan 2,00 phr untuk selanjutnya diwakili dengan penomoran 1, 2, 3, 4 dan 5 dan PP pwd untuk blangko. Sampel masterbatch MFC, MCC, HPN dan PP dilakukan karakterisasi dengan uji FTIR, XRD, DSC dan Tarik. Hasilnya menunjukkan bahwa MCC dan MFC dapat meningkat derajat kristalinitas, suhu leleh, suhu kristalisasi dan kekuatan tarik polimer PP walaupun belum menyamai kinerja dari HPN. Persentase optimum masterbatch PP+MFC5 dan PP+MCC4 dengan peningkatan derajat kristalinitas masing-masing sebesar 19,96% dan 18,24% terhadap PP murni. Namun, belum dapat menyamai kinerja HPN pada kondisi optimum masterbatch PP+HPN5 dengan peningkatan derajat kristalinitas sebesar 54,80%. Persentase optimum masterbatch PP+MFC5 dan PP+MCC5 pada peningkatan suhu leleh masing-masing sebesar 2,8°C dan 3,3°C terhadap PP murni. Namun, belum dapat menyamai kinerja HPN pada kondisi optimum masterbatch PP+HPN2 dan masterbatch PP+HPN3 dengan peningkatan suhu leleh yang sama yaitu sebesar 4,4°C. Persentase optimum masterbatch PP+MFC4, PP+MFC5 dan PP+MCC5 pada peningkatan suhu kristalisasi masing-masing sebesar 5,0°C, 5,0°C dan 5,7°C terhadap PP murni. Namun, belum dapat menyamai kinerja HPN pada kondisi optimum masterbatch PP+HPN5 dengan peningkatan suhu kristalisasi sebesar 19,0°C.

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Polypropylene (PP) is a thermoplastic polymer used in a variety of applications. Crystallization process is a process that has an important role in PP production. The addition of a nucleating agent that serves to shorten the crystallization induction time of certain polymers, including PP. The purpose of this study was to analyze the effect of adding microcrystalline cellulose (MCC) and microfibrillated cellulose (MFC) as nucleating agent additives to the PP crystallization process and to obtain the optimum percentage compared to Hyperform HPN-20E (HPN) as commercial nucleating agent and Pure PP. MFC is made by alkalization, bleaching and hydrolysis. MFC and MCC were characterized by SEM and XRD. Each of the MFC, MCC and HPN were internally mixed with PP pwd with a concentration of 0.10; 0.20; 0.40; 1.00 and 2.00 phr are then represented by numbering 1, 2, 3, 4 and 5 and PP pwd for blanks. The MFC, MCC, HPN and PP masterbatch samples were characterized by FTIR, XRD, DSC and Tensile tests. The results show that MCC and MFC can increase the degree of crystallinity, melting temperature, crystallization temperature and tensile strength of PP polymer although they cannot match the performance of HPN. The optimum percentages of PP+MFC5 and PP+MCC4 masterbatches with increasing degree of crystallinity were 19.96% and 18.24%, respectively, compared to pure PP. However, it has not been able to match the performance of HPN under the optimum conditions of the PP+HPN5 masterbatch with an increase in the degree of crystallinity of 54.80%. The optimum percentages of PP+MFC5 and PP+MCC5 masterbatches at increasing melting temperatures were 2.8°C and 3.3°C, respectively, for pure PP. However, it has not been able to match the performance of HPN under the optimum conditions of the PP+HPN2 masterbatch and PP+HPN3 masterbatch with the same increase in melting temperature of 4.4°C. The optimum percentages of PP+MFC4, PP+MFC5 and PP+MCC5 masterbatches at increasing crystallization temperature were 5.0°C, 5.0°C and 5.7°C for pure PP, respectively. However, it has not been able to match the performance of HPN under the optimum conditions of the PP+HPN5 masterbatch with an increase in crystallization temperature of 19.0°C."

"Konsumsi polimer dalam jumlah besar, menekan industri polimer untuk menghemat bahan baku material dan mempercepat laju produksi. MFC berbasis serat alam telah dipelajari mampu memperbaiki sifat dan kecepatan laju proses dari polimer. Indonesia sebagai negara agraris memiliki banyak sumber serat alam, salah satunya serat ijuk. Melalui proses perlakuan, serat alam diproses hingga didapatkan MFC yang akan dipelajari sifatnya sebagai agen penukleasi didalam polimer polipropilena jenis kopolimer impak. Dengan penambahan MFC, dapat meningkatkan 2% kristalinitas dan kecepatan kristalinitas hingga 12 detik. Penelitian ini menitik beratkan pada kemampuan kristalinitas dari PP setelah ditambahakan MFC.

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Polymer comsumption in large scale, pushing polymer industry to reduce consumption of base material and increasing production time. ?Ijuk? based MFC has been studied can improve quality and accelerate process on PP. Indonesia as a maritime nation had many kind land riches, the one is ?ijuk? fiber. By conditioning process, ?ijuk? fiber made into MFC than have good bonding and will be studied his properties as nucleating agent on polymer polypropylene copolymer impact. With addiction of "

"Polipropilena (PP) merupakan polimer termoplastik yang banyak digunakan. PP memiliki densitas yang rendah, mudah diproses, dapat didaur ulang, dan relatif murah, tetapi kekuatan tariknya rendah. Penggabungan PP dengan serat kenaf dapat meningkatkan sifat mekanik PP. Namun, PP dan serat kenaf memiliki kompatibilitas yang rendah. Oleh karena itu, serat kenaf diberi perlakuan pemutihan dengan NaClO 1% selama 2 jam pada temperatur ruang. Serat dikarakterisasi dengan FTIR, FESEM, dan uji tarik. Pemutihan menurunkan kandungan hemiselulosa, lignin, dan zat pengotor pada permukaan serat serta meningkatkan kekuatan tarik serat. Proses pencampuran PP dan serat kenaf dilakukan dengan metode hot melt mixing. Pencampuran dilakukan dengan komposisi serat 5% hingga 25% fraksi massa, temperatur 170oC hingga 190oC, dan waktu 10 menit hingga 20 menit. Komposit dikarakterisasi dengan FESEM, uji tarik, dan STA. Penambahan serat 5% fraksi massa menghasilkan komposit dengan kekuatan tarik, kristalinitas, dan kestabilan termal yang paling tinggi. Temperatur pencampuran 190oC menghasilkan komposit dengan kekuatan tarik, kristalinitas, dan kestabilan termal yang paling tinggi. Waktu pencampuran 20 menit menghasilkan komposit dengan kekuatan tarik paling tinggi.

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PP is a thermoplastic polymer which is widely used. PP has low density, easily processed, can be recycled, and relatively inexpensive, but has low tensile strength. Synthesis PP with kenaf fiber can improve the mechanical properties of PP. However, PP and kenaf fiber have low compatibility. Therefore, kenaf fiber treated by bleaching with NaClO 1% for 2 hours in room temperature. Fiber characterized by FTIR, FESEM, and tensile test. Bleaching reduces hemicellulose, lignin, and impurities on the fiber surface and increase the tensile strength of fiber. PP and kenaf fiber mixing is done by hot melt mixing method. Mixing is done with fiber composition of 5% to 25% mass fraction, temperature of 170oC to 190oC, and time of 10 minutes to 20 minutes. Composites characterized by FESEM, tensile test, and STA. The addition 5% mass fraction of fiber results a composite with the highest tensile strength, crystallinity, and thermal stability. Mixing temperature of 190oC results a composite with the highest tensile strength, crystallinity, and thermal stability. Mixing time of 20 minutes results a composite with the highest tensile strength."