Pengaruh Waktu dan Suhu Reaksi Grafting pada Proses Pembuatan Maleated Natural Rubber

Natural rubber can be modified through the grafting process. of maleic anhydride (MAH). Maleic anhydrade has been grafted into natural rubber to make a compound called Maleated Natural Rubber (MNR). The aiming in this research is learning of the reaction time effect and the temperature of natural rubber grafting process. Furthermore,kinetics reaction of the grafting process has to be learned. Independent variables are 8 phr of MAH and 60 rpm rotor speed of internal mixer. Dependent variables are reaction temperature and reaction time, which are variated by 150oC, 155oC, 160oC, and 165 of reaction temperature, and 6, 8, 10, 12, 14 minutes of reaction time. The degree of grafting was determined by titrimetric method, meanwhile kinetics reaction is learned by assumption of pseudo - first order to get the value of the constant rate of reaction (k). The results showed the optimum temperature is 160oC and reaction time is 12 minutes. Best conditions of the kinetics reaction has been obtained at reaction temperature 155o and 165oC, which produced constant rate of reaction is 0.004 min - 1, activation energy is 6107 cal / mo , hereby the Arrhenius equation : k = 4,65 e-6071/R

Sintesa Precipitated Calcium Carbonate (PCC) dari Cangkang Kerang Darah (Anadara Granosa) dengan Variasi Ukuran Partikel dan Waktu Karbonasi

Precipitated Calcium Carbonate (PCC) is a product of the processing of natural materials containing calcium carbonate resulting from the precipitation process with high purity. Bloodcockle shell can be used as a source of calcium for precipitated Calcium Carbonate. The purpose of this study to produce PCC of waste shells blood with carbonation method and determine the particle size of the PCC and the best carbonation time. Synthesis performed using carbonation method by adding nitric acid to the slaking process. Blood cockle shell samples prior shells calcined at a temperature of 900°C for 3 hours to form calcium oxide and then dissolved with nitric acid (slaking process) with a particle size variation CaO (+ 20-60; + 60- 100; +100-120) mesh forming CaNO3, then added ammonia to pH 12, the next process of Ca (OH)2 CO2 gas flowing until the time was varied (0.5, 1, 1.5) hours to form a white precipitate which is precipitated Calcium Carbonate. The use of inorganic acids in this study aims to improve the solubility of CaO in the slaking process so that a high yield of the products obtained.The highest yield of PCC obtained at treatment +100-120 mesh particle size and carbonation time of 1.5 hours, with the percentage yield of 88.58%. Results of analysis Atomic Absorption Spectrophotometry (AAS) obtained CaCO3 content of 76.6%. From the pattern of X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM) can be seen form the resulting crystal is a mixture vaterit and calcite

Pembuatan Biodiesel dari Sawit Off-Grade dengan Proses Dua Tahap

Off-grade palm oil is a source of untapped vegetable oil. Off-grade palm oil can be used as an alternative raw material for biodiesel production despite having high content Free Fatty Acid (> 5%). Plant with a capacity of 30 tones of FFB yield 7-10% off-grade palm oil or 2-3 tons per hour. The catalyst used is potassium hydroxide because it has smaller ionization energy, making it faster to form a product when used as a catalyst. This research aims to produce biodiesel from low-quality raw materials and determine the effectiveness of the process by looking at the effect of process conditions such as reaction temperature, molar ratio and catalyst concentration on the yield of biodiesel. The biodiesel making process was carried out with two stages of the reaction, esterification and transesterification reactions due to high content of free fatty acid in the raw material. Data processing in this study was analyzed by response surface methodology (RSM) using Design Expert 8.0 program. Experiment runs were determined by central composite design (CCD), which consists of three variables, namely temperature, catalyst concentration and molar ratio of methanol to oil. The highest biodiesel yield was 88.56% (%wt) obtained under the conditions of reaction temperature 60 °C, the molar ratio of methanol to oil 8:1 and the concentration of 1% KOH base catalyst. The characteristics of biodiesel produced in the form of density, kinematic viscosity, acid number and flash point are in accordance with the standards of Indonesian biodiesel. Catalyst concentration have a significant influence on the yield of biodiesel

Sintesa Precipitated Calcium Carbonate (PCC) dari Cangkang Kerang Darah ( Anadara Granosa) dengan Variasi Jenis Asam dan Waktu Karbonasi

Precipitated Calcium Carbonate (PCC) can be synthesized from blood cockle shell through three methods, namely the method of solvay, soda caustic, and carbonation. The method used in this research that was the carbonation process in the modification, the use of acid solvent during the slaking process to obtain higher yields. The purpose of this research was to synthesize precipitated calcium carbonate (PCC) of blood cockle shell by varying the type of solvent and acid carbonation time. A number of blood cockle shell powder was calcined at 900oC temperature to calcium oxide (CaO) form, then CaO was dissolved into some acid solvents (HNO3, HCl, and CH3COOH). Furthermore, the carbonation process with carbonation time variation 30, 60, and 90 minutes. Based on AAS analysis CaO content in the blood cockle shells was 76.66%, which detected as aragonite crystals. The highest yield of PCC was 84.42% for 90 minute carbonation time by using of HNO3 as solvent. For the XRD patterns it recognized that PCC contained mixture vaterit and calcite crystals. It also was supported by SEM analysis