Judul: Development of vegetable oil-based zincdifattyalkyldithiocarbamate lubricant additive production process
Abstrak: Dithiocarbamate is an organosulfur compound which has many functions and applications in the various industries. In the field of automotive and metal working, these compounds are used as additives lubricants, in agriculture as pesticides, in pharmaceuticals as an antioxidant. In this study, we synthesized Zinc-difattyalkyldithiocarbamates compounds using materials which were derived from vegetable oil. Furthermore, performance test of the synthesized product as antioxidant and antiwear-antifriction in lubrication system was carried out. Zinc-difattyalkyldithiocarbamates complexes were synthesized by reacting primary fatty amines with acyl chlorides formed secondary fatty amides, continued with reducing the corresponding product to secondary fatty amines using LiAlH4, and finally secondary fatty amines were reacting with ZnCl2 and CS2, to formed Zinc-difattyalkyldithiocarbamates. Each corresponding of product were successfully synthesized with range of yield were 10 to 87, 17 to 96, and 77 to 87% respectively. The synthesis of primary fatty amines to secondary fatty amides, secondary fatty amides to secondary fatty amines, and secondary fatty amines to Zincdifattyalkyldithiocarbamates complexes were evaluated from fourier transformation infra red (FTIR) spectrum quality with the wave number of 3300 cm-1 for NH vibration, 1639 cm-1 for C=O vibration, 1454 cm-1 for tioureida C-N vibration, 968 cm-1 for C-S vibration, and in the far infra-red area with the wave number of 387 cm-1 that showed the maximum absorption of M-S bond (sulfur metal). Besides using the FTIR spectrum, Zinc-difattyalkyldithiocarbamates complexes formation were also evaluated by Zinc-recovery test using atomic absorption spectrophotometer (AAS), and conformity purity test using high performance liquid chromatography (HPLC). All variants of Zinc-difattyalkyldithiocarbamates synthesized were done using rancimat test method and four ball test method to determine the antioxidant activity and antiwear-antifriction activity. At the same concentration of 125 ppm, all variants of product showed the antioxidant activity higher than the BHA, BHT, and commercial additives control. The highest antioxidant activity was obtained by three variants of the Zinc-bis(dilauryl)dithiocarbamate, Zincbis( laurylpalmityl)dithiocarbamate, and Zinc-bis(laurylstearyl)dithiocarbamate. At the same concentration of 1.2%, all variants of product showed the welding point higher than the lube base oil HVI 60 as base lubricants, and US Steel 136 as extreme pressure standard additive, but only Zincbis( laurylpalmityl)dithiocarbamate and Zinc-bis(lauryloleyl)dithiocarbamate showed load wear index higher than both of these base lubricants and standard. Zinc-bis(laurylpalmityl)dithiocarbamate was the best of antioxidant and antiwearantifriction additive compared to others homologous compounds of product. Conversion of crude palm oil to palmityc acid, palmytic acid to hexadecylamine, and hexadecylamine to Zinc-bis(laurylpalmityl)dithiocarbamate additive can increase the value of the product. With assumption, the cost of raw material as Rp.8.520,-/kg and the product value Rp.1.210.000,-/kg, therefore industry will able to generate added value with Rp.8.135,-/kg, and Rp.6.290,-/kg of company profit.
Keyword: fattyamines, fattyamides, Zn-difattyalkildihtiocarbamates, antioxidant, antiwear-antifriction, added value, Vegetable Oil

Judul: Density funtional theory dalam sintesis, karakterisasi, dan prediksi aplikasi. Kasus: senyawa Zn-dialkylditiokarbamat rantai panjang
Abstrak: Coordination compounds of dialkyldithiocarbamate have broad applications, e.g. automotive lubricant additives. Coordinated long chain dialkyldithiocarbamate was studied to obtain the better anti-friction and anti-wear. Integration of computation chemistry e.g. density functional theory used to identify reaction mechanisms, to optimize geometry of structure, and to estimate properties of compounds. The aim of this study was to obtain long chain complexes Zn-dialkyldithiocarbamate, to examine their structures, and to estimate their applications using Density Functional Theory methods (DFT). Long chain Zn-dialkyldithiocarbamate was synthesized through reaction between ZnCl2, NaOH, CS2 and secondary amine during 24 hours in room condition. Secondary amine was obtained from LiAlH4 reduction of amide 2o during 24 hours in nitrogen atmospheric. Reaction of long chain amine 1o and long chain acylchloride was used to obtain amide 2o. DFT and instrumentation (FTIR and HPLC) was used to study of mechanism, structure elucidation and its application. The results showed the synthesis of Zn-dibutyldithiocarbamate, dipalmitilamide, dipalmitilamine, Zn-dipalmitildithiocarbamate yields are 90.02%, 90.91%, 47.5%, and 66.49% respectively. The ratio of intensity and wave number for Zndibutyldithiocarbamate from FTIR spectra and DFT calculations wasn’t significantly different at 95% confidence level. According to DFT calculation (B3LYP/ 6-31G*), the carbon-sulfur bonds in Zn-dibutyldithiocarbamate have an average length of 0.1683-0.1743 nm and the ligand “bite” angle S-C-S has a mean value of 116.85o. This result indicates a tetrahedral-shaped Zndibutyldithiocarbamate. Lubricant additives (anti-wear and anti-friction) properties of Zn-dialkyldithiocarbamates was estimated by chemical hardness and absolute electronegativity. Lower electronegativity value is better anti-friction, and lower chemical hardness is better anti-wear. Anti-friction ability of Zndialkyldithiocarbamate is better than Mo-dialkyldithiocarbamate, while anti-wear ability is lower than Zn-dialkiydithiophosphates. Based on electronegativity absolute value of DFT calculations, the Zn-dialkyldithiocarbamate is categorized as superlubricity that can perform in the boundary lubricant system.
Keyword: 

Judul: Karakteristik Suara Song Burung Kenari (Serinus canaria) Postur Besar dan Kecil.
Abstrak: Burung kenari (Serinus canaria) memiliki nyanyian yang sangat bervariasi dengan durasi yang panjang dan merupakan tipe burung bernyanyi open learners. Penelitian ini bertujuan menganalisis karakteristik suara song burung kenari (Serinus canaria). Penelitian dilakukan pada bulan April sampai Juni 2017 di Bogor, Jawa Barat. Perekaman suara song terhadap 12 ekor burung kenari jantan dilakukan dengan menggunakan mikrofon Sennheiser ME66 dan alat perekam Sony PCM-D50. Burung kenari yang digunakan merupakan burung yang pernah mengikuti kontes burung kicau dan memiliki predikat juara kontes burung. Amplitudo, durasi suara, frekuensi, dan volume suara burung dianalisis dengan menggunakan software Raven Pro 1.4. Data tersebut selanjutnya dianalisis deskriptif. Hasil analisis suara menunjukkan bahwa burung kenari memiliki banyak syllable, suara song rapat dan tidak terputus-putus, tempo yang cepat, dan adanya pengulangan suku kata pada setiap suara song. Burung kenari postur kecil memiliki rataan durasi lebih panjang dibandingkan dengan kenari postur besar, tetapi burung kenari besar memiliki rataan max amplitudo, average power, max power, min amplitudo, peak amplitudo, dan peak frekuensi.
Keyword: karakteristik suara (song), kenari, syllable