Desi Suci Handayani

Physicochemical Properties of Biosurfactant Produced by Pseudomonas fluorescens Grown on Whey Tofu

The research aims to examine the physicochemical properties of biosurfactant produced by Pseudomonas fluorescens. Biosurfactant was produced in whey tofu media containing 8 g/L nutrient broth and 5 g/L NaCl which was fermented for 2 days at room temperature. Biosurfactant was identified as rhamnolipids which had critical micelle concentration (CMC) value of 638 mg/L and surface tension of 54 mN/m. The biosurfactant had water in oil (w/o) emulsion type. The biosurfactant was able to decrease the interfacial tension more than 40% for emulsion of water with hexane, pentane, benzene, lubricants or kerosene. The stable emulsions were reached up to 30 days with the E24 value of about 50% when paraffin, toluene, lubricants or palm oil was used as an immiscible compound. Commercial surfactants, such as Triton X-100 and Tween-80 were investigated to compare their emulsification activities and emulsion stabilities with the produced biosurfactant.

Ethyl-2-(3,5-Dihidroxyfenol): Phloroglucinol derivatives as potential anticancer material

Ethyl-2-(3,5-dihidroxyfenol) based phloroglucinol compounds have been synthesized. Ethyl-2-(3,5-dihidroksifenol) were synthesized by reacting phloroglucinol with ethyl 2-chloro acetate in excess. Phloroglucinol reaction using 2-chloro ethyl acetate was carried out under reflux for 24 hours at a temperature of 56 oC. The reaction products were identified by a thin layer chromatography and were characterized by melting point test. Analysis of the structure of the products was obtained by FTIR spectrophotometer, H-NMR, and 13C-NMR. The result of the reaction between phloroglucinol and 2-chloro ethyl acetate was brownish black solid, and has a melting point of 191 oC. Based on the structural analysis by FTIR, 1H-NMR and 13C-NMR, the reaction product was a mixture of compounds which is ethyl 2- (3,5-dihidroksifenol) acetate, ethyl-2-(2,4,6-trioxocyclohexyl) acetate, and the rest of phloroglucinol which can not react.

Adsorption of remazol yellow FG from aqueous solution on chitosan-linked P-T-Butylcalix[4]Arene

Chitosan-liked p-t-butylcalix[4]arene can be applied as an adsorbent of dye Remazol Yellow FG because it has an active group of hydroxy (-OH) and amine (-NH2). Adsorption had done by comparing to chitosan. Adsorption was carried out in a batch system. Several variables including pH, contact time, and initial concentration of dye Remazol Yellow FG were determined. The optimum adsorption conditions of dye Remazol Yellow FG by chitosan dan chitosan-liked p-t-butylcalix[4]arene occurred at pH 4 and a contact time of 135 minutes. The adsorption kinetics of dye Remazol Yellow FG using chitosan and chitosan-liked p-t- butylcalix[4]arene followed Ho kinetics model, pseudo-second order and the rate constant of adsorption was 2.42 x 10-4 g/mg.menit and 3.63 x 10-4 g/mg.menit. The isothermal study showed that adsorption of dye Remazol Yellow FG using chitosan and chitosan-liked p-t- butylcalix[4]arene tends to follow the Langmuir isotherm, with adsorption energy was 24.92 kJ/mol and 32.21 kJ/mol.

Heat Combustion, Tensile Strength and Biodegradability of Recycled Polypropylene Modified Multifunctional Agent Composites in the Presence of Pineapple Leave Fiber and Bentonite

Had been synthesized different composites from recycled polypropylene (rPP) using Pineapple leave Fiber (PaF), commercial Bentonite (comBen) and zinc borate (ZB). In the optimum formula with ratio rPP/PaF/comBen was 65/15/20 (w/w) and 5 % ZB of different composites are measured their flame retardancy, tensile strength (TS) and biodegradability. This new rPP/PaF/comBen/ZB composites materials have heat combustion (Hg), tensile strength (TS) and biodegradability better than the starting materials. The Hg of rPP/PaF/comBen/ZB decreased to 28%. The TS of rPP/PaF/comBen/ZB according to ASTM D 638 arised to 83%. The biodegradability of rPP/PaF/comBen/ZB in burial test arised to 15.7%.

SUBSTITUSI IPTEKS PEMBESARAN LELE TEBAR PADAT

Petani pembesaran lele banyak yang mengeluh gagal dalam usaha pembesaran lele. Kegagalan tersebut disebabkan oleh penggunaan pakan dan kolam yang tidak efisien serta harga pakan mahal. Tujuan kegiatan pengabdian masyarakat ini memberikan wawasan tentang metode baru dalam usaha pembesaran lele yang menguntungkan. Mitra pengabdian kegiatan ini yaitu kelompok pembesaran lele Sungut Emas di Boyolali dan petani-petani pembesaran lele disekitarnya. Metode pengabdian dilakukan dengan metode substitusi ipteks secara teori, praktek lapangan, dan pendampingan. Substitusi ipteks secara teori meliputi penjelasan tentang pembesaran lele tebar padat dan aplikasi enzim dalam efisiensi pakan. Materi praktek lapangan meliputi cara persiapan air, cara pengelolaan air, cara menangani penyakit dan cara memberi pakan. Simpulan, substitusi ipteks pembesaran lele tebar padat mampu menyelesaikan masalah yang dihadapi petani pembesaran lele tebar padat sehingga keuntungan usaha meningkat.

Preparation of Silanized-Chitosan via Solution-Casting Method: Study on the Mechanical, Water Adsorption and Swelling Area Properties

Silanizing of chitosan has been prepared using the solution-casting method. The silanizing agent is 3-glycydiloxypropyl trimethoxysilane (GPTMS). The compounding of chitosan/GPTMS was conducted for 1 hour at 80°C by varying GPTMS compound (5-20 wt %) and the final product is referred as Cs/GPTMS. The mechanical properties, including tensile strength, elongation and young modulus were tested according to ASTM D882-02. The addition of 15 % of GPTMS was able to improve the tensile strength value up to 55.66%. However, the elongation decreased to 64.89 %. Moreover, the water adsorption and swelling area properties were studied in this research to evaluate the material ability. Both of water adsorption and swelling area properties decreased by the presence of GPTMS in chitosan. The Cs/GPTMS materials to be promising candidate materials for plastic engineering due to their properties meet the requirement.

Effect of single flame retardant aluminum tri-hydroxide and boric acid against inflammability and biodegradability of recycled PP/KF composites

Composites rPP/DVB/AA/KF had been reactively synthesized in melt using starting material: recycled polypropylene (rPP), kenaf fiber (KF), multifunctional compound acrylic acid (AA), compatibilizer divinyl benzene (DVB). To improve the inflammability of composites, single flame retardant aluminum tri-hydroxide (ATH) and boric acid (BA) as an additive was added. The inflammability of the composites was tested according to ASTM D635. By using 20% ATH and 5% BA additive in the composites it is effectively inhibiting its time to ignition (TTI). Its burning rate (BR) can be reduced and its heat realease (%HR) decreases. The biodegradability of composites was quantified by its losing weight (LW) of composites after buried for 4 months in the media with rich cellulolytic bacteria. The result shows that the LW of composites in the presence 20% ATH and 5% BA is 6.3%.

Effect of cyclical thermal to mechanical properties of Hybrid Laminate Composites (HLC) with skin recycle polypropylene/natural fiber/halloysite and core PP/KF composites

This research has successfully synthesized six hybrid laminate composites (HLC). These HLC consist of two layers skin composites and one layer of core PP/KF composites. There are sticked with epoxy adhesive by using cold press method. In this research 6 types of skin are used, namely the rPP (recycled polypropylene, HC1); rPP/DVB/PP-g-AA/KF (HC2); rPP/DVB/PP-g-AA/Hall (HC3); rPP/DVB/PP-g-AA/Hall+ZB (HC4); rPP/DVB/PP-g-AA/KF/Hall (HC5) and rPP/DVB/PP-g-AA/KF/Hall+ZB (HC6) composites. The mechanical properties assessment tensile strength (TS) of various HLC before and after cyclical thermal (CT) was done by ASTM D638. While testing the flame retardant: such as time to ignition (TTI) and burning rate (BR) was done by ASTM D635. Heat stability of HLC can be recognized by conducting the CT treatment. It is to determine the effect of fluctuating heat loads on mechanical properties of HLC materials. The TS result of five HLCs (HC2, HC3, HC4, HC5 and HC6) before CT treatment were higher than HC1 (blank HLC). Those five HLC are also able to increase the TTI and reduce the BR compared to HC1. The CT treatment conditions performed at 45 oC as much as 125 times. After CT treatment, the TS values only slightly decline compared to before CT treatment.

Synthesis of perfume compound etil p-anisat from anethole

Synthesis of ethyl p-anisate from anethole have been done. Ethyl p-anisate is ester coumpound which can use as perfume component. p-anisic acid was synthesized from anethole (1 mole) which oxidixed by KMnO4 (3 moles) at 40o C for 2 hours. Esterification with ethanol carried out at 78,5o C for 6 hours. Identification and determination structure coumpound of product synthesis used spectroscophic methodes (GC, GC-MS and IR). Anethole has been isolated from anise oil as 90,3%. p-Anisic acid and ethyl p-anisate as synthesized products got 45% and 79,9% respectively. Keywords: anethole, p-anisic acid, esterification, ethyl p-anisate.