Analisis Termal Aspal Modifikasi Poliuretan Alam dari Getah Pinus Merkusii (Jungh et de Vries) dan Peg 400 dengan Penambahan Toluena 2,4-Diisosianat

Abstract

This study examines the modification of polymer asphalt with polyurethane through several stages. The first stage involves the production of polyol from Pinus merkusii resin by reacting it with 90% formic acid and 30% H₂O₂. Functional group analysis using FTIR indicates successful hydroxylation, evidenced by the O-H stretching vibration at 3409.8 cm⁻¹. This O-H group can react with diisocyanates to form polyurethane. The next stage is the formation of polyurethane by reacting Pinus merkusii polyol with PEG 400 in varying ratios of natural polyol to commercial polyol: 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0, with the addition of toluene 2,4-diisocyanate. FTIR analysis confirms the successful formation of polyurethane, indicated by characteristic wavelengths for N-H, C=O, C-N, and C-O groups. The study also measures the swelling degree to determine crosslinking in polyurethane, showing that the 0:100 and 20:80 polyurethane ratios have the highest crosslinking with the lowest swelling degree of 7,20% and 5,69%. Thermal analysis using TGA indicates that polyurethane with a 20:80 ratio starts decomposing at 194°C, leaving 21.13% of the sample, demonstrating better thermal stability compared to the 0:100 ratio. The 20:80 polyurethane is mixed with asphalt in ratios of 20:80, 30:70, and 40:60. FTIR analysis of the Asphalt-PU shows successful modification, with functional groups from both asphalt and additional functional groups at 1630-1680 cm⁻¹, confirming the presence of C=O carbonyl groups from urethane bonds. Additionally, TGA thermal analysis of asphalt modified with 20:80 polyurethane shows decomposition starting at around 320°C with a weight loss of 58.50%. It can be concluded that polyurethane-modified asphalt with a 20:80 ratio is the most optimal variation.