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"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%."

"Film selulosa bakteri telah berhasil dibuat dari air kelapa sebagai sumber mikronutrien menggunakan biakan Acetobacter xylinum. Film selulosa bakteri selanjutnya diiradiasi dengan mesin berkas elektron pada rentang dosis 15-120 kGy, laju dosis 15 kGy/ pass dan temperatur ruang. Setelah diiradiasi, selulosa bakteri tersebut dikopolimerisasi cangkok dengan monomer akrilonitril. Kondisi optimum untuk kopolimerisasi cangkok akrilonitril pada selulosa bakteri adalah pada dosis 75 kGy, temperatur 600C, waktu 3 jam, dan konsentrasi akrilonitril 30% b/b. Derajat pencangkokan tertinggi yang diperoleh adalah sebesar 56,03 %. Selulosa bakteri tercangkok akrilonitril (SB tercangkok PAN) selanjutnya diamidoksimasi. Amidoksimasi dilakukan dengan penambahan hidroksilamin hidroklorida 6 % b/v dalam pelarut metanol : air = 50 : 50 v/v pada pH 7, dan diperoleh waktu optimum selama 2 jam dengan densitas gugus amidoksim yang diperoleh sebesar 5,425 mmol/ gram. Karakterisasi gugus fungsi film selulosa bakteri sebelum dan sesudah kopolimerisasi cangkok dengan akrilonitril, serta setelah diamidoksimasi dilakukan dengan menggunakan Fourier Transform Infra Red (FTIR), analisis mikrostruktur dengan Scanning Electron Microscopy (SEM), analisa derajat kristalinitas menggunakan X-ray diffraction (XRD), serta uji ketahanan terhadap panas diukur dengan Thermal Gravimetry Analysis (TGA) dan Differential Scanning Calorimetry (DSC). Hasil karakterisasinya mengindikasikan bahwa SB tercangkok PAN dan selulosa bakteri teramidoksimasi (SB-Am) telah berhasil disintesis pada penelitian ini. Film tersebut selanjutnya diuji kemampuan adsorpsinya terhadap ion logam Cu2+ dan Pb2+. Nilai koefisien distribusi selulosa bakteri, SB tercangkok PAN, dan SB-Am pada pH 6 terhadap ion logam Cu2+ masing-masing sebesar 0,26, 0,23, dan 0,37 L/gram adsorben, sedangkan terhadap ion logam Pb2+ masing-masing sebesar 0,41, 0,405, dan 0,52 L/gram adsorben.

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Bacterial cellulose films have been successfully synthesized from coconut water as a source of micronutrients using Acetobacter xylinum. Bacterial cellulose film irradiated using electron beam machine at a dose range of 15-120 kGy and dose rate 15 kGy/ pass in room temperature. After irradiated, the bacterial cellulose grafted with acrylonitrile monomer. The optimum conditions for graft copolymerization condition were at the dose of 75 kGy, temperature 600C ,3 hours time of reaction, and the concentration of acrylonitrile was 30 % w/w. The highest degree of grafting obtained was 56,03 % . Amidoximation then performed by the addition of hydroxylamine 6 % w/v in methanol : water = 50 : 50 v/v solvent under pH 7 and obtained the optimum time for amidoximation reaction was 2 hours. Amidoxime density obtained was 5.425 mmol/ gram. Characterization of functional groups in bacterial cellulose films before and after graft copolymerization with acrylonitrile, as well after amidoximation performed by Fourier Transform Infrared (FTIR), microstructure was analyzed by Scanning Electron Microscopy (SEM), analysis of the degree of crystallinity using X-ray diffraction (XRD), thermal resistance properties was measured by Thermal Gravimetry Analysis (TGA) and Differential Scanning Calorimetry (DSC) .The results show that bacterial cellulose-g-polyacrylonitrile (BC-g-PAN) and amidoximated bacterial cellulose films (Am-BC) have been synthesized successfully. Subsequently, Cu2+ and Pb2+ metal ion adsorption studies were conducted using those films. Coeficient distribution of bacterial cellulose, BC-g-PAN, and Am-BC under pH 6 toward Cu2+ions respectively were 0,26, 0,23, dan 0,37 L/gram of adsorbent, while toward Pb2+ions, respectively were 0,41, 0,405, and 0,52 L/gram of adsorben."

"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.

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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."

"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.

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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."

"Modifikasi selulosa dengan asam akrilat menggunakan pengikat silang Trimethallyl Isocianurate (TMAIC) dengan teknik kopolimerisasi cangkok pra-iradiasi telah berhasil dilakukan. Penelitian ini bertujuan untuk menghasilkan suatu material bersifat adsorben. Pengikat silang TMAIC digunakan untuk meningkatkan ketahanan kimia dan termal dari selulosa-g-AA. Kondisi optimum reaksi pencangkokan diperoleh pada dosis radiasi 60 kGy, konsentrasi TMAIC 0,5 % (w/v), konsentrasi monomer 10 % (v/v), suhu pencangkokan 90°C dan waktu pencangkokan 6 jam, dengan persen pencangkokan rata-rata sebesar 65,27 % dan pengembangan dalam air sebesar 922,26%. Hasil sintesis kopolimer selulosa-TMAIC-g-AA telah berhasil dikarakterisasi dengan FTIR, TGA dan SEM. Selulosa terikat silang dapat digunakan sebagai adsorben ion logam Pb2+, dengan kapasitas adsorpsi sebesar 2,5954 mg/g pada waktu kontak 2 jam dan pH 5 (konsentrasi awal Pb2+ 10 mg/L). Isoterm adsorpsi yang sesuai dengan adsorpsi Pb(II) dengan kopolimer adalah isoterm adsorpsi Langmuir dengan linearitas 0,9868.

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Modification of cellulose with acrylic acid monomers using Trimethallyl Isocianurate ( TMAIC ) as crosslinker by mean of preirradiation graft copolymerization technique have been successfully carried out. This research aims to produce a material which has adsorbent properties. TMAIC as crosslinking agent can be used to improve the chemical and thermal resistance of cellulose-g-AA. The optimum condition for graft copolymerization is obtained at 60 kGy radiation dose, 0,5 % (w/v) TMAIC, 10 % (v/v) monomer, 90°C grafting temperature and 6 hours reaction time, with 65,27 % grafting average and 922,26 % swelling in water. Synthesized copolymers cellulose-TMAIC-g-AA was successfully characterized by FTIR, TGA and SEM. Crosslinked cellulose-TMAIC-g-AA can be used as Pb2+ metal adsorbent, having adsorption capacity of 2,5954 mg/g at 2 hours contact time and pH 5 (initial concentration of Pb2+ 10 mg/L). Adsorption isotherms in accordance with the adsorption of Pb ( II ) by copolymer is Langmuir adsorption isotherm with linearity 0.9868."

"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."

"Pada penelitian ini dilakukan sintesis kopolimer pH-sensitif poli(N-vinil pirolidon)-blok-poli(N-hidroksimetil akrilamida) menggunakan metode atom transfer radical polymerization (ATRP) dengan memvariasikan komposisi monomer N-hidroksimetil akrilamida untuk melihat pengaruhnya terhadap sensitivitas kopolimer blok tersebut pada berbagai pH. Untuk melihat gugus fungsi yang terdapat pada kopolimer digunakan FT-IR, sedangkan struktur kopolimer dikarakterisasi menggunakan 1H-NMR. Kemudian, karakterisasi menggunakan particle size analyzer dilakukan untuk melihat sensitivitas dari kopolimer dengan melihat perubahan ukuran partikel kopolimer pada berbagai pH. Dalam penelitian ini, kopolimer poli(N-vinil pirolidon)-blok-poli(N-hidroksimetil akrilamida) mengalami perubahan ukuran partikel pada berbagai pH. Pada pH asam ukuran partikel kopolimer akan lebih besar dibandingkan pada pH basa. Selain itu, semakin banyak komposisi monomer N-hidroksimetil akrilamida maka ukuran partikel akan lebih besar.

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In this reseach, the synthesis of pH-sensitive poly(N-vinyl pyrrolidone)-block-poly(N-hydroxymethyl acrylamide) was carried out using atom transfer radical polymerization (ATRP) by varying the monomer composition of N-hydroxymethyl acrylamide to observe the effect of monomer composition on copolymer sensitivity at various pH. Functional groups in copolymers were characterized using FT-IR, and the structures of copolymers were investigated with ¹H-NMR. In order to observe copolymer sensitivity to pH, characterization using particle size analyzer was performed by studying the changes in particle sizes of copolymers at various pH. In this research, particle sizes of poly(N-vinyl pyrrolidone)-block-poly(N-hydroxymethyl acrylamide) changes in various pH. At low pH, the particle sizes of copolymers became much bigger than at high pH. Besides that, particle sizes increased along with the increasing monomer composition of N-hydroxymethyl acrylamide."

"[ABSTRAKSifat karet alam dapat ditingkatkan melalui modifikasi kimiawi secara reaksikopolimerisasi cangkok emulsi karet alam terdeproteinisasi (DPNR) denganmonomer vinil (MV) tunggal maupun paduannya menggunakan inisiatorammonium peroksidisulfat dan surfaktan sodium dodesil sulfat menghasilkankaret alam termoplastik (TPNR). Reaksi dijalankan secara eksitu pada suhu 65ºCselama 5 jam dilanjutkan pada 70ºC selama 1 jam dengan teknik batch padaberbagai komposisi DPNR terhadap MV dan rasio paduan MV (stirena (ST)terhadap metil metakrilat (MMA)). Hasil penelitian secara umum menunjukkanbahwa TPNR yang disintesis dari DPNR dengan paduan MV menggabungkansifat unggul TPNR yang diperoleh dari hasil reaksi DPNR dengan MV tunggal.Komposisi DPNR terhadap MV sebesar 60 : 40 dengan rasio ST terhadap MMAsebesar 2 : 1 ditetapkan sebagai kondisi teroptimum dalam reaksi kopolimerisasicangkok emulsi pembentukan TPNR.

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ABSTRACTNatural rubber properties can be improved by chemical modification suchemulsion graft copolymerization of deproteinized natural rubber (DPNR) witheither single or combination of vinyl monomers (MV) by using ammoniumperoxydisulfate as initiator and sodium dodecyl sulfate as surfactant to producethermoplastic natural rubber (TPNR). The reaction was run at 65ºC for 5 hourscontinued at 70ºC for an hour by exitu ? batch procedure at various proportion ofDPNR to single MV and combination of MV ratio (styrene (ST) to metylmethacrylate (MMA)). Generally, the result showed that TPNR synthesized fromDPNR and combination of MV integrated the prior properties of TPNRsynthesized from DPNR and single MV. The proportion of DPNR to MV as 60 :40 and ratio of ST to MMA as 2 : 1 were regarded as the best condition onemulsion graft copolymerization in the formation of TPNR., Natural rubber properties can be improved by chemical modification suchemulsion graft copolymerization of deproteinized natural rubber (DPNR) witheither single or combination of vinyl monomers (MV) by using ammoniumperoxydisulfate as initiator and sodium dodecyl sulfate as surfactant to producethermoplastic natural rubber (TPNR). The reaction was run at 65ºC for 5 hourscontinued at 70ºC for an hour by exitu – batch procedure at various proportion ofDPNR to single MV and combination of MV ratio (styrene (ST) to metylmethacrylate (MMA)). Generally, the result showed that TPNR synthesized fromDPNR and combination of MV integrated the prior properties of TPNRsynthesized from DPNR and single MV. The proportion of DPNR to MV as 60 :40 and ratio of ST to MMA as 2 : 1 were regarded as the best condition onemulsion graft copolymerization in the formation of TPNR.]"