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"ABSTRACTOriginally, only oils of vegetable origin, which were at the most subjected to a heat treatment (stand oil manufacture), were used as binder for the paint.The oils mostly applied are linseed oil and Lung oil, and recently also oiticica oil. These so called drying oils - when spread out in a thin layer - possess the ability to change under the influence of air and light into a hard, more or less water-repelling, and thus into a protective film within a relatively short period.For the manufacture of paints, varnishes, and laquers, these oils are mixed with other materials which contribute to the formation of the desired properties of the protective layer. The Linum usitatissimum, the source of linseed oil, grows only in areas with a temperate climate and cannot grow in a large. scale in iadonesia.Attempts to transplant in Indonesia the Aleuritus Fardid and the Aleuritus Montana - the seeds of which supply the tung oil - were already made in 1835 and later on repeated in the years 1930 to 1935.It appeared that the A. Fordie could not flourish in Indonesia, while the A. Montana; better able to withstand the Indonesian rlimatic conditions, gives strongly varying results from place to place.Frahm and Koolhaas were able to prepare a drying oil with reasonable properties from locally collected seeds of A. Montana. The susceptibility of the plant to various influences however, hindered its development into a big culture seriously.Other possibilities for the production of drying oils (from the seeds of Aleuritus trisperma oiticica, families of parinarium are probably present, but an investigation to the productiveness of such cultures will be time consuming In connection with the above mentioned general scarcity of drying oils, extensive attempts are carried out in many countries of the world to manufacture drying oils by means of chemical processes. Except in a single case where the drying properties in the raw material, prior to the chemical process, are scarcely present (castor oil), the starting point is a natural product, which already possesses certain drying properties. Such processes present Indonesia with the possibility of finding a solution for the above mentioned problem of binders."

"ABSTRAKRosin atau gondorukem merupakan residu penyulingan getah pohon pinus (oleorosin) . Rosin terdiri antara 85 - 90 % asam-asam resin serta 10 - 15 % komponen-komponen natal. Rosin produksi Indonesia yang umumnya berasal dari spesies Pinus merkusii, ternyata mempunyai kadar asam abietat lebih rendah dibandingkan rosin produksi negara lain seperti Cina, Portugis dan Amerika. Kecilnya kandungan asam abietat ini diduga sebagai salah satu faktor yang menyebabkan kualitas rosin produksi Indonesia lebih rendah dibandingkan rosin produksi negara-negara lain.Sebagian besar asam resin yang terdapat dalam rosin merupakan isomer satu sama lain. Oleh karena itu dengan proses isomerisasi yang tepat dapat terjadi perubahan suatu asam resin menjadi asam resin lain, yang mengakibatkan terjadi perubahan komposisi asam resin dalam rosin.Pada penelitian ini telah dicoba dua teknik isomerisasi, yaitu isomerisasi termal dan isomerisasi dengan katalis asam, dengan tujuan dapat menghasilkan peningkatan kadar asam abietat dari rosin.Kondisi optimum pada isomerisasi termal diperoleh dengan melakukan variasi suhu pemanasan antar 1850C samapai 2500C. Sedangkan pada isomerisasi dengan katalis dilakukan variasi konsentrasi katalis antara 0,6 M sampai 1,4 M. Kadar asam abietat dalam rosin isomerisasi diukur dengan alat Kromatografi Gas.Hasil penelitian menunjukkan balk isomerisasi dengan pemanasan maupun dengan katalis asam, dapat meningkatkan kadar asam abietat dalam rosin. Isomerisasi dengan pemanasan menghasilkan kadar asam abietat maksimum pada temperatur pemanasan 250 ° C yaitu sebesar 69,83% dari kadar awal sebelum pemanasan 21,23 %. Isomerisasi dengan katalis asam menghasilkan kadar asam abietat maksimum pada penggunaan katalis dengankonsentrasi 1,2 M yaitu sebesar 61,81 %. Penggunaan konsentrasi Iebih pekat tidak menunjukkan peningkatan lagi.Walaupun dua proses dapat menghasilkan peningkatan kadar asam abietat, tetapi isomerisasi dengan teknik pemanasan mempunyai beberapa keunggulan yaitu proses yang lebih sederhana dan tidak menimbulkan perubahan warna pada rosin dibandingkan sebelum isomerisasi. Sedangkan isomerisasi dengan bantuan katalis asam membutuhkan banyak tahap perlakuan dan warna rosin menjadi lebih gelap dibandingkan keadaan awal sebelum isomerisasi.

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ABSTRACT

Rosin is obtained from pine tree after the volatile oil or turpentine was remove. Rosin consists of 85 - 95 % resin acids and 10 - 15 % neutral components. In Indonesia rosin is usually produced from species of Pinus merkusii which has abietic acid content lower than rosin produced from China, Portugal, and America. The lower content of abietic acid could be the one of the factor causing Indonesian rosin quality to be lower than those of other country.

Mayority of resin acids formula in the rosin are isomer to each other. Consequecently, the correct isomerization process can transform the resin acid to another resin acid. It means that the acid composition of the total rosin changes.

In this experiment two isomerization techniques had been used. They are thermal isomerization and acid catalyzed isomerization, which the objective is to increase the abietic acid content. To obtain the optimum condition of thermal isomerization the variation of temperatures are use between 185 0 C to 250 ° C. Whereas in acid catalyzed isomerization the variation of catalyst concentrations were performed between 0,6 M to 1,2 M . The abietic acid content after isomerization process was measured by gas chromatography.

Experimental results show that thermal isomerization as well as acid catalysed isomerization, can increase abietic content in the rosin. Thermal Isomerization can enchance maximum abietic content 69.83 % from the initial content t 21.23 %). The optimal temperature of thermal isomerisasi can achieve by 250 C. Using the concentration of mineral acid, 1.2 M, as catalyst can inverse the maximum abietic acid content to 61.81 % from initial amount :31.82 %.

Although the two process above can increase the result of abietic content, but thermal isomerization has certain advantages over acid catalyzed isomerization . That is because the technique is simple and no color change in rosin compared to condition before isomerization. Whereas isomerization with aid of acid catalyst requires several stages of treatment and the rosin colour becames darker than the initial condition before isomerization."