Pemanfaatan Asap Cair dari Limbah Kayu Karet (Hevea brasiliensis) sebagai Bahan Pengawet dan Pewarna Kayu Karet

Pemanfaatan sisa hasil olahan kayu karet dapat dimanfaatkan untuk dibuat menjadi asap cair. Asap cair dapat digunakan sebagai antimikrobia, antioksidan, anti rayap dan memberikan efek warna. Berdasarkan beberapa sifat tersebut maka penelitian ini akan memanfaatkan limbah kayu karet olahan sebagai asap cair yang akan digunakan sebagai pengawet dan pewarna kayu karet olahan. 
Asap cair diproses dengan cara pirolisis pada suhu 400 oC dan waktu 90 menit. Asap cair diteliti rendemen, berat jenis, indeks bias, kadar fenol, karbonil dan asam. Asap cair kemudian diaplikasikan pada kayu karet olahan dalam dua kondisi (kondisi basah dan kering) selama 1, 4 dan 7 hari. Kayu karet olahan hasil aplikasi diuji absorbsi dan retensi asap cair, mortalitas rayap serta perbedaan warna kayu. 
Hasil penelitian menunjukkan rendemen asap cair limbah kayu karet sebesar 39,86 %, berat jenis 1,03, indeks bias 1,36, kadar fenol 1,52 %, kadar karbonil 8,32 % dan kadar asam sebesar 9,26 %. Hasil aplikasi asap cair pada kayu olahan mendapatkan hasil absorbsi asap cair ke dalam kayu sebesar 0,0755 - 0,4412 gram/cm3. Nilai retensi asap cair ke dalam kayu sebesar 0,0285 – 0,1988 gram/cm3. Mortalitas rayap semakin besar (rayap semakin cepat mati) dengan semakin lamanya waktu perendaman kayu dalam asap cair dan mortalitas rayap 100 % dicapai pada hari ke 5-21, sedangkan pada kayu kontrol mortalitas rayap 100 % dicapai pada hari ke 88 - 135. Warna kayu akan semakin kurang cerah (semakin gelap atau kuning kecoklatan) dengan semakin lamanya waktu perendaman dalam asap cair.

Kata kunci : asap cair, kayu karet, rayap, pengawetan kayu, pewarnaan kayu.

Abstract
The waste materials of processed rubber wood can be utilized to make liquid smoke. Liquid smoke can be used as antimicrobial, antioxidant, anti-termite and coloring effects. Based on some properties, this research will utilize the waste materials of processed rubber wood as the liquid smoke that will be used as the creosote and dye of processed rubber wood. The liquid smoke is processed by using a pyrolysis procedure at 400 oC and the time of 90 minutes. Objects investigated in the liquid smoke are rendemen, specific gravity, refractive index, phenol content, carbonyl content, and acid content. The liquid smoke is then applied on the processed rubber wood in two (wet and dry) conditions for 1.4 and 7 days. The processed rubber wood as a result of the application is tested for both the absorption and retention of liquid smoke, termite mortality, and the difference of wood color. Result of the research indicates that the rendemen of liquid smoke of the processed rubber wood was 39.86 %, specific weight 1.03, bias index 1.36, phenol content 1.52 %, carbonyl content 8.32 %, and acid content 9.26 %. The application of liquid smoke on the processed rubber wood indicated that the result of liquid smoke absorption into the wood was 0.0755-0.4412 gram/cm3. Value of the liquid smoke retention into the wood was 0.0285-0.1988 gram/cm3. Termite mortality was increasingly high (termites died more quickly) with the longer time of wood immersion into liquid smoke, and the termite mortality was 100% at 5- 21st days, while on the wood control, the termite mortality was 100% at 88-135th days. The wood color was increasingly less bright (increasingly darker or brownish yellow) with the longer time of wood immersion into liquid smoke.
Keywords : Liquid smoke, rubber wood, termite, wood preservation, wood dying.