Oil-absorptive expanded polyurethane(EPU) was prepared with a lypophilic polyol, polypropyleneglycol(PPG) as the soft segment, and toluenediisocyanate(TDI)and H₂O as the hard segment. PPGs having various average molecular weights(M_n: 1000, 2000, 3000) were employed to investigate that the soft segment content was consequent on the oil-absroptivity and the mechanical properties of the EPUs. As M_n of PPG was decreased from 3000 to 1000, the oil-absroptivity and the tensile strength of the EPUs increased from 1460 to 3010% and from 0.26 to 0.55kg_f/cm² respectivity. As the hard segment content ratio, γ([NCO]/[OH])was increased from 1.0 to 1.2, the tensile strength of the EPUs increased from 0.56 to 0.95 kg_f/cm², dut to the formation of allophanate and/or biuret bondings. However, as the surfactant(S-A) content was increased frem 1.0 to 2.5 pbw, the oil-absorptivity was decreased from 3634 to 3312% due to the formation of closed cell structures.

흡유성이 우수한 발포 폴리우레탄(EPU)을 제조하기 위하여 soft segment로는 친유성 polyo인 polyprolyleneglycol(PPG)를 사용하고 hard segment로는 toluenediisocyanate(TDI)와 H₂O를 사용하였다. Soft segment함량이 흡유성과 발포체의 기계적 특성에 미치는 영향을 조사하기 위하여 PPG평균 분자량 (M_n 1000, 2000, 3000)에 따라 one-shot법으로 EPU를 제조한 결과 PPG 평균분자량이 3000에서 1000으로 감소할수록 흡유량과 인장강도는 각각 1460%에서 3010%, 0.26kg_f/cm로 동시에 증가하였다. Hard segment 함량비인 (isocyanate index, γ=[NCO]/[OH]) γ이 1.0에서 1.2로 증가할수록 allophanate와 biuret 결합 형성에 기인하여 EPU의 인장강도가 0.56kg_f/cm에서 0.95kg_f/cm로 증가하였으나, surfactant(S-A)의 함량은 1.0pbw에서 2.5pbw로 증가할수록 closed cell 구조의 형성으로 인하여 흡유량이 3634%에서 3312%로 감소됨을 알 수 있었다.

Keywords: oil absrotion; expanded polyurethane; cell structure; polyol; isocyanate