Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
Graft copolymerization of an acrylonitrile monomer onto Deproteinized Natural Rubber (DPNR) is an important process in the modification of Natural Rubber (NR) to increase its oil resistance. However, coagulation at the beginning of the process was a problem causing a copolymerization foil to occur. The presence of a styrene monomer is therefore expected to improve the emulsion condition so that coagulation can be prevented in the early reaction step. For comparison purposes, the processes with and without styrene were investigated. The influence of the concentration of styrene as well as the ratio of the DPNR:monomer on the stabilization process were also observed. The results showed that the addition of styrene could improve the stabilization process as proven by Fourier Transform Infrared Spectroscopy (FTIR). The presence of the functional group of CºN at FTIR proved the production of the polyacrylonitrile in the mixture. The investigation showed that the concentration of styrene monomer, which led to the emulsion stability, is up to 1.5 wt% concentration of styrene at the ratio of DPNR:monomer (M) of 70:30 wt%.

Abstrak :
Penelitian ini bertujuan untuk mendapatkan kopolimer cangkok DPNR-g-PAN/PS yang tahan terhadap DME dengan melakukan uji perendaman terhadap DME berdasarkan pengaruh rasio monomer akrilonitril dan stirena. Hasil penelitian menunjukkan bahwa monomer akrilonitril (AN) dapat dicangkokkan pada karet alam dengan stirena (ST) sebagai ko-monomer. Dari karakteristik analisis spektrum dengan FTIR didapatkan gugus CN dan gugus benzena yang merupakan gugus dari poliakrilonitril (PAN) dan polistirena (PS). Karakterisasi temperatur transisi gelas (Tg) dengan DSC menunjukkan bahwa nilai Tg kopolimer DPNR-g-PAN/PS lebih tinggi dari Tg DPNR. Dari karakteristik Efisiensi Cangkok (EC) didapatkan nilai tertinggi adalah 73,21%. Berdasarkan karakteristik cure didapatkan bahwa semakin kecil rasio AN/ST, nilai optimum cure semakin tinggi dan scorch time yang semakin rendah. Hasil dari sifat-sifat fisik tensile strength, elongation at break dan hardness menunjukkan keberhasilan kopolimerisasi. Pengujian DPNR dan DPNR-g-PAN/PS dilakukan dalam DME. Semakin besar komposisi monomer (M) dan AN, semakin kecil persentase swelling massa dan volume. Komposisi AN untuk swelling terendah adalah 92%. Komposisi ST optimal untuk memperkecil shrinkage adalah 20%. Swelling massa dan volume terrendah dicapai pada 23,14% dan 31,90%. Shrinkage massa dan volume terrendah dicapai pada masing-masing -3,64% dan -3,86%. Pada analisis spektrum FTIR karet vulkanisat, kemungkinan putusnya ikatan rangkap C=C hanya karena interaksi DME pada DPNR bebas. Hal ini yang menimbulkan terjadinya shrinkage. Kehadiran PAN sebagai polimer bebas dapat berfungsi sebagai penahan difusi, sehingga total PAN yang tergrafting dan PAN bebas dapat memperkecil swelling dan shrinkage. Pada perubahan sifat fisik, interaksi karet DPNR ataupun DPNR-g-PAN/PS dengan DME menyebabkan menurunnya nilai tensile strength, elongation at break dan hardness. Pada analisis SEM terlihat perbedaan yang terjadi akibat swelling dan shrinkage massa dan volume setelah perendaman. Pada pengujian perbandingan dengan Nitrile Butadiene Rubber (NBR) hasil menunjukkan bahwa daya tahan terhadap DME adalah NBR-1 < DPNR-g-PAN/PS < NBR-2. Dari hasil pengujian-pengujian dapat disimpulkan bahwa proses kopolimerisasi cangkok dapat meningkatkan daya tahan karet alam terhadap DME.

---

This study aims to obtain graft copolymer DPNR-g-PAN/PS which is resistant to immersion DME. The immersion test of the DME based on the ratio acrylonitrile and styrene monomer. The results showed that the monomer acrylonitrile (AN) can be grafted on natural rubber with styrene (ST) as co-monomer. From the characteristics of the FTIR spectrum analysis obtained CN groups and clusters of benzene which is a group of polyacrylonitrile (PAN) and polystyrene (PS). Characterization of the glass transition temperature (Tg) by DSC shows that Tg values copolymer DPNR-g-PAN/PS higher than Tg DPNR. The characteristics of the Grafting Efficiency (GE) obtained the highest value is 73.21%. Based on the cure characteristics, it was found that the smaller the ratio AN/ST, the higher of the optimum cure and the lower scorch time. The results of the physical properties of tensile strength, elongation at break and hardness show success copolymerization. The immersion test DPNR and DPNR-g-PAN/PS performed in DME. The larger the monomer composition (M) and AN, the smaller the percentage of swelling mass and volume. The composition of AN to the lowest swelling is 92%. ST optimal composition to minimize the shrinkage is 20%. The lowest of the swelling mass and volume reached at 23.14% and 31.90% respectively. Mass and volume shrinkage achieved at the lowest -3.64% and -3.86% respectively. In the FTIR spectrum analysis of vulcanized rubber, the possibility of the outbreak of the C=C double bond simply because of the interaction of the DPNR free and DME. This has led to an shrinkage. The presence of PAN as a free polymer can serve as a diffusion barrier, so that the total PAN grafted and PAN free can reduce swelling and shrinkage. On the change of physical properties, interaction DPNR rubber or DPNR-g-PAN/PS with DME caused a decline in the value of tensile strength, elongation at break and hardness. In the SEM analysis of visible differences that occur due to swelling and shrinkage of mass and volume after immersion. In comparative testing with a Nitrile Butadiene Rubber (NBR) results indicate that resistance to DME is NBR-1 < DPNR-g-PAN/PS < NBR-2. From the results of the tests can be concluded that the graft copolymerization process can improve the resistance of natural rubber to the DME.

Abstrak :
Industri ban menyerap sekitar 80% produksi karet dunia dengan kebutuhan carbon black sebanyak 240.000 ton per tahun. Carbon black (CB) umumnya digunakan sebagai filler karet ban untuk meningkatkan sifat mekanis dan memberikan pigmen warna hitam. Sampai saat ini,70% kebutuhan CB masih diimpor dari China dan India. Lignin TKKS merupakan senyawa aromatik dengan kandungan karbon sebesar 60% yang berpotensi sebagai reinforcing filler karet ban setelah terdekomposisi menjadi biochar. Penelitian ini bertujuan untuk memperoleh karakteristik unsur dan morfologi nano-biochar pada suhu 400, 500, dan 600oC serta memperoleh pengaruh rasio nano-biochar terhadap CB N330 pada sifat mekanis karet ban. Nano-biochar pada setiap suhu dianalisis karakteristik fisika-kimianya. Hasil penelitian menunjukkan yield biochar berkurang seiring dengan meningkatnya suhu pirolisis. Jumlah fixed carbon dan kandungan karbon tertinggi diperoleh pada suhu pirolisis 600oC. Sementara itu, luas permukaan biochar tertinggi diperoleh pada suhu pirolisis 500oC sebesar 86,79 m2/g.  Struktur biochar yang lebih berpori diperoleh pada suhu 600oC. Sifat mekanis karet ban lebih tinggi pada tensile strength, elongation at break, modulus 100%, tear strength, dan hardness diperoleh ketika SBR dicampur dengan filler 25% nano-biochar. Hal ini membuktikan potensi biochar sebagai komplemen karbon CB N330 dalam meningkatkan sifat mekanis karet ban. ......The tire industry absorbs about 80% of the world's rubber production with a carbon black requirement of 240,000 tons per year. Carbon black (CB) is commonly used as a tire rubber filler to improve mechanical properties and provide black pigment. Until now, 70% of CB needs are still imported from China and India. Lignin of TKKS is an aromatic compound with a carbon content of 60% which has the potential as a reinforcing filler for tire rubber after being decomposed into biochar. This study aims to obtain the elemental and morphological characteristics of nano-biochar at temperatures of 400, 500, and 600oC and to obtain the effect of the ratio of nano-biochar to CB N330 on the mechanical properties of tire rubber. Nano-biochar at each temperature was analyzed for its physico-chemical characteristics. The results showed that the biochar yield decreased as the pyrolysis temperature increased. The highest amount of fixed carbon and carbon content was obtained at 600oC pyrolysis temperature. Meanwhile, the highest biochar surface area was obtained at 500oC pyrolysis temperature of 86.79 m2/g.  A more porous biochar structure was obtained at 600°C. Higher mechanical properties of tire rubber in tensile strength, elongation at break, 100% modulus, tear strength, and hardness were obtained when SBR was mixed with 25% nano-biochar filler. This proves the potential of biochar as a complement to CB N330 carbon in improving the mechanical properties of tire rubber.

Abstrak :
Berbagai limbah styrofoam kemasan (PS) pada penelitian ini digunakan untuk membuat natrium polistirena sulfonat (NaPSS). PS disutfonasi dengan asam sulfat pekat 98% menggunakan sulfonasi heterogen dan homogen dengan pelarut dikloroetana (DCE) dengan berbagai variasi suhu (60, 80 dan 100 °C) dan variasi waktu reaksi (3, 4, 5, dan 6 jam). Produk sulfonasi diidentifikasi dengan spektroskopi FTIR. Adanya puncak pada bilangan gelombang 1140 dan 1040 cm"'datam spektrum infra merah menunjukkan karakteristik gugus sulfonat. Persentase sulfonasi maksimum yang dihasilkan adalah 74,9% dengan menggunakan sulfonasi heterogen pada kondisi suhu 100 °C dan waktu reaksi 6 jam sedangkan persentase sulfonasi maksimum yang dihasilkan dengan menggunakan sulfonasi cair-cair adalah 81,91% pada kondisi suhu 100 °C dan waktu reaksi 4 jam. Herat molekul rata-rata limbah styrofoam yang digunakan pada penelitian berkisar antara 90.000 -92.800 g/mol dan menghasilkan NaPSS dengan berat molekul antara 125.000 - 136.000 g/mol. Larutan NaPSS diaplikasikan sebagai flokulan pada proses pengolahan air danau dan dibandingkan dengan aquaklir, flokulan yang telah beredar di pasaran. Hasil menunjukkan bahwa NaPSS dapat menurunkan nilai turbiditas air danau dari 24,58 ntu menjadi sekitar 1 ntu, hal ini masih kurang optimum bila dibandingkan dengan aquaklir.

---

Several kinds of polystyrene packaging waste (PS) were used in the synthesis of sodium polyfstyrene sulfonate) (NaPSS). PS was sulfonated by using sulfonic acid under heterogeneous and Iquid-liquid sulfonation reactions with dichloroetane (DCE) as solvent. The reactions were conducted at three different temperatures i.e. 60, 80 and 100 °C and at four different reactions time (3, 4, 5 and 6 hours). The product was characterized by FTIR spectrophotometer. The absorption at 1140 and 1040 cm"1 in the infrared spectrum was characteristic for sulfonic groups. The maximum percentage sulfonation was found 74.9% for heterogeneous sulfonation at 100 °C and 6 hours reactions time and the maximum percentage sulfonation for Iquid-liquid sulfonation was found 81.91% at 100 °C and 4 hours reactions time. An aqueous solution of NaPSS was used as a flocculant in lakes water treatment, compared with aquaklir, a commercial flocculant. The results showed that NaPSS can decrease turbidity of water from 24.58 ntu to about 1 ntu, which was less than aquaklir.

Abstrak :
ABSTRAK
Styrene Acrylic adalah sebuah produk kimia yang digunakan sebagai bahan baku adhesive, coating dan cat. Untuk memproduksi Styrene Acrylic diperlukan sebuah reaktor yang berfungsi sebagai wadah dimana reaksi antar bahan-bahan dasar Styrene Acrylic terjadi. Reaksi yang terjadi dalam reaktor harus terkendali agar dapat mengikuti resep formula yang sudah ditentukan. Salah satu faktor yang utama yang harus dikendalikan adalah suhu dalam reaktor. Suhu dalam reaktor harus sesuai dengan formula yang telah ditetapkan agar kualitas dari produk sesuai dengan yang diinginkan. Toleransi eror suhu dalam reactor hanya diperbolehkan sebesar 5?C. Selain untuk menjaga kualitas produk, pengendalian suhu reaktor juga berdampak pada alasan kemanan pabrik. Reaksi kimia dan proses produksi Styrene Acrylic memiliki sifat yang nonlinear, sehingga diperlukan pengendali yang dapat mengendalikan sistem nonlinear dengan toleransi eror yang kecil. Fuzzy logic diharapkan dapat memenuhi kebutuhan pengendalian suhu reaktor, sehingga suhu reaktor dapat mengikuti trajektori suhu yang didapat dari resep formula yang mana ditentukan sebagai setpoint.Skripsi ini membahas tentang pemodelan dan desain pengendali yang baik untuk model proses Styrene Acrylic plant. Proses ini dimodelkan dengan metode matematis yang diterapkan menggunakan C-Mex. lalu di simulasikan menggunakan Simulink Matlab yang digunakan untuk mendesain pengendali PID konvensional dan fuzzy logic. Pengendali PID di-tuning menggunakan metode Ziegler Nichols yang mana performanya akan dibandingkan dengan performa pengendali fuzzy logic yang didesain dengan 9 aturan.

---

ABSTRACT
Styrene Acrylic is a chemical product used as raw material for adhesives, coatings and paints. To produce Styrene Acrylic requires a reactor that serves as a container in which the reaction between the basic ingredients of Styrene Acrylic occurs. The reactions that occur in the reactor must be controlled in order to follow a prescribed formula. One of the main factors that must be controlled is the temperature in the reactor. The temperature in the reactor shall be in accordance with the prescribed formula for the quality of the product to be as desired. Tolerance of temperature error in the reactor is only allowed at ± 5⁰C. In addition to maintaining product quality, reactor temperature control also has an impact on manufacturers' safety reasons. Chemical reactions and Styrene Acrylic production processes have nonlinear properties, so controllers are required to control nonlinear systems with small error tolerance. Fuzzy logic is expected to meet the reactor temperature control requirement, so that the reactor temperature can follow the temperature trajectory obtained from the formula or recipe which is set as setpoin.

This thesis discusses the modeling and design of a good controller for the Styrene Acrylic plant process model. This process is modeled by a mathematical method applied using C-Mex. Then simulated using Simulink Matlab which is used to design conventional PID controller and fuzzy logic. The PID controller is tuned using the Ziegler Nichols method whose performance will be compared to the performance of a fuzzy logic controller designed with 9 rules.

Abstrak :
Polimerisasi stirena melalui sistem bulk dengan menggunakan dua jenis inisiator redoks yaitu H2O2/Asam askorbat dan H2O2/Fe2+ telah berhasil dilakukan. Penelitian ini bertujuan untuk mempelajari pengaruh variasi konsentrasi dan komposisi masing-masing inisiator serta variasi temperatur terhadap persen konversi dan berat molekul rata-rata polimer. Dengan konsentrasi dan komposisi inisiator yang sama, inisiator redoks H2O2/Asam askorbat menghasilkan persen konversi yang lebih besar daripada inisiator H2O2/Fe2+. Terhadap polistirena dari masing-masing inisiator redoks yang dihasilkan dilakukan karakterisasi berat molekul rata-rata, dan didapat hasil: 196.170,44 gram mol-1 untuk konsentrasi inisiator H2O2/Asam askorbat 3% dengan komposisi 6:1 dan suhu 900C dalam waktu 5 jam; dan 354.413,28 gram mol-1 untuk konsentrasi inisiator H2O2/Fe2+ 2% dengan komposisi 3:1 dan suhu 950C dalam waktu 5 jam. Polistirena dengan inisiator H2O2/Asam askorbat menghasilkan persen konversi yang lebih besar dan berat molekul rata-rata yang lebih kecil daripada polistirena dengan inisiator H2O2/Fe2+. ......Polystyrene was prepared by bulk polymerization method with two types of redox initiator, namely H2O2/Ascorbic acid and H2O2/Fe2+. This research has studied the effect of variation concentration and composition from each redox initiator and also temperature reaction to percent conversion and average molecular weight. With the same concentration and composition of initiator, percent conversion of initiator H2O2/Ascorbic acid was larger than initiator H2O2/Fe2+. Average molecular weight characterization has been measured after polystyrene was produced from each redox initiator, and the yield: 196.170,44 gram mole-1 for redox initiator H2O2/Ascorbic acid with 3% concentration, composition 6:1, temperature at 900C in 5 hours; and 354.413,28 gram mole-1 for redox initiator H2O2/Fe2+ with 2% concentration, composition 3:1, temperature at 950C in 5 hours. Polystyrene from H2O2/Ascorbic acid initiator has larger percent conversion and lower average molecular weight than initiator H2O2/Fe2+.

Abstrak :
Pada penelitian ini dilakukan pembuatan aditif peningkat indeks viskositas berbasis lateks karet alam (Deproteinized Natural Rubber) melalui reaksi kopolimerisasi lateks karet alam-stirena (LKA-Stirena) dengan menggunakan inisiator benzoil peroksida. Selanjutnya, LKA-Stirena yang terbentuk dilarutkan ke dalam xylena setelah dipisahkan dari homopolimer. Produk yang diperoleh diuji kemampuannya dalam meningkatkan indeks viskositas pada minyak lumas dasar HVI 160. Produk dilarutkan ke dalam pelarut untuk memperoleh aditif peningkat indeks viskositas. Sebanyak 5% aditif ditambahkan ke dalam minyak lumas HVI 160 untuk diukur indeks viskositasnya dengan menggunakan metode ASTM D2270. Penambahan aditif dapat meningkatkan indeks viskositas minyak lumas HVI 160 dari 98 menjadi 129,05.

---

In this research, preparation of viscosity index improver additive base of natural rubber latex (Deproteinized Natural Rubber) is done through copolymerization reaction to natural rubber latex-styrene (LKA-styrene) using benzoyl peroxide initiator. Furthermore, LKA-formed styrene dissolved into xylena after being separated from Homopolymers. Products obtained tested for its ability in improving the viscosity index lubricating oil base in HVI 160. Product was dissolved into the solvent to obtain a viscosity index improver additive. As many as 5% additives added to HVI 160 lubrication base oil for viscosity index measurement using ASTM method D2270. Additive derived can increase the viscosity index of lubricating oil HVI 160 from 98 to 129.05.

Abstrak :
This study aimed to determine the effect of using acrylonitrile butadiene styrene in place of conventional wax material on treatment pattern removal in the investment casting process. There are three controllable process variables that can affect treatment pattern removal, which include temperature increase, holding time and the number of layers of ceramic shell that have been considered for comparison. Comparison among the effects of temperature increase, holding time and numbers of ceramic shell layers on the ceramic shell was analyzed using ANOVA. It was found that temperature increase (Tx), holding time (t) and number of layers of ceramic shell (N) contribute significantly to the length of the crack (l) on the ceramic shell. The crack in the ceramic shell?s surface was analyzed using scanning electron microscope photos. Less layers number cause the increase of crack length. The combination between temperature upraise and longer holding time cause cracking delay. The experimental is conducted by using 3 (three) variants for each of layers number, temperature and holding time. The layers number is ranging between 7-9 layers. Temperature increase from room temperature until 1300oC. The layers number variant is ranging between 180-300 seconds. It was concluded that a longer holding time will result in a more intact ceramic shell, as longer holding times yield short crack lengths.

Abstrak :
Diversifikasi barang jadi karet alam sangat diperlukan untuk mendukung peningkatan konsumsi domestik produksi karet alam nasional. Salah satu upaya yang dapat dilakukan adalah dengan memanfaatkan karet alam termoplastik hasil kopolimerisasi cangkok emulsi lateks karet alam dengan monomer termoplastik sebagai bahan aditif jenis peningkat indeks viskositas minyak pelumas. Penelitian ini dimaksudkan untuk mempelajari pengaruh penambahan berbagai dosis karet alam termoplastik (kopolimer dari karet alam - stirena) ke dalam minyak lumas dasar golongan parafinik HVI 60 dan HVI 650 terhadap nilai indeks viskositas minyak pelumas baru. Hasil penelitian menunjukkan bahwa reaksi kopolimerisasi cangkok emulsi yang dijalankan pada rasio karet alam terhadap monomer stirena sebesar 85:15, pada suhu 65oC selama 7 jam, dengan penambahan 1% insiator amonium peroksidisulfat dan 2% surfaktan sodium dodesil sulfat mampu menghasilkan karet alam termoplastik (TPNR, kopoli NR-ST) dengan efisiensi cangkok 56,48%. Pada dosis 5% TPNR terhadap minyak lumas dasar berfungsi dengan baik sebagai peningkat indeks viskositas karena memenuhi persyaratan indeks viskositas standar sesuai Surat Keputusan Ditjen Migas Nomor 85K/34/DDJM/1998, dan dapat bersaing dengan minyak pelumas komersial tipe 20W-50, 10W-40 dan 15W-40. ......Diversification of rubber goods are highly needed to enhance natural rubber domestic consumption. One of the efforts is by using thermoplastic natural rubber that is synthesized from emulsion graft copolymerization of natural rubber latex with thermoplastic monomer as index viscosity improver of lubricating oil. The research aimed to study the effect of thermoplastic natural rubber (natural rubber?styrene copolymer) addition, at various concentration, into base paraffinic lube oil (HVI 60 and HVI 650) on index viscosity value of lubricating oil. The result showed that emulsion graft copolymerization at composition ratio of natural rubber to styrene monomer 85:15, at 65oC for 7 hours, with addition of 1% ammonium peroxidisulfate as initiator and 2% sodium dodecyl sulfate as surfactant produced thermoplastic natural rubber (TPNR, copoly NR-ST) with grafting efficiency of 56,48%. The TPNR can be functioned properly as index viscosity improver at 5% concentration to base paraffinic lube oil either HVI 60 or HVI 650. The obtaining new lubricating oils could fulfill the index viscosity standard requirement refered to Decree of Directorat General of Oil and Gas No 85K/34/DDJM/1998, and could compete with the commercial lubricating oil type 20W-50, 10W-40, and 15W-40.