A Comparative Study on Polyurethane Coating Films Prepared Using 4,4'-Methylenebis(2-chloroaniline) and 1,3-Propanediolbis(4-aminobenzoate) as Crosslinking Agents

4,4'-Methylenebis(2-chloroaniline)과 1,3-Propanediolbis(4-aminobenzoate)를 가교제로 사용하여 제조한 폴리우레탄 코팅 필름의 특성 비교

  • Lee, Youn-Sik (Division of Environmental and Chemical Engineering, The Nanomaterials Research Center, Chonbuk National University) ;
  • Lee, Sung-Il (Division of Environmental and Chemical Engineering, The Nanomaterials Research Center, Chonbuk National University) ;
  • Kim, Duk-Bae (Division of Environmental and Chemical Engineering, The Nanomaterials Research Center, Chonbuk National University) ;
  • Park, Young-Deok (Department of Chemistry, Chonbuk National University) ;
  • Kim, Jung-Kee (Division of Environmental and Chemical Engineering, The Nanomaterials Research Center, Chonbuk National University) ;
  • Hahn, Yoon-Bong (Division of Environmental and Chemical Engineering, The Nanomaterials Research Center, Chonbuk National University) ;
  • Nahm, Kee-Suk (Division of Environmental and Chemical Engineering, The Nanomaterials Research Center, Chonbuk National University)
  • 이연식 (전북대학교 환경.화학공학부) ;
  • 이성일 (전북대학교 환경.화학공학부) ;
  • 김덕배 (전북대학교 환경.화학공학부) ;
  • 박영덕 (전북대학교 화학과) ;
  • 김정기 (전북대학교 환경.화학공학부) ;
  • 한윤봉 (전북대학교 환경.화학공학부) ;
  • 남기석 (전북대학교 환경.화학공학부)
  • Published : 2004.03.31

Abstract

4,4'-Methylenebis(2-chloroaniline)(MOCA) has been widely used as a crosslinking agent, but classified as a toxic chemical. Thus, its use will be limited in the near future. In this research, polyurethane coating films were prepared using 1,3-propanediolbis(4-aminobenzoate)(PDBA) as an alternative to MOCA. The base part was prepared by melting MOCA or PDBA in polyoxypropylene($M_n$=2000), followed by the addition of the various additives. The NCO-terminated toluene diisocyanate prepolymer was used as a curing agent. The polyurethane coating films were prepared by mixing the base part with the curing agent in an appropriate ratio at room temperature. The polyurethane coatings prepared using PDBA exhibited higher initial viscosity, but much longer pot lift, compared to those prepared using MOCA under the same conditions, due to lower reactivity of PDBA. The tensile strength and tear strength of the coating films were much weaker. However, the pot life, tensile strength, elongation, and tear strength of the coating films, prepared using PDBA in the presence of an increased amount of Pb(II)-octoate, were close to those of the coating films prepared using MOCA. Thus, it was concluded that PDBA can substitute MOCA in the preparation of polyurethane coatings as long as the reactivity of PDBA is enhanced using appropriate amounts of the catalyst or other appropriate catalyst.

폴리우레탄 탄성체의 가교제로 널리 사용되고 있는 4,4'-methylenebis(2-chloroaniline)(MOCA)는 현재 독성이 높은 물질로 분류되어 있기 때문에 머지않아 사용이 제한될 전망이다. 본 연구에서는 MOCA와 유사한 구조를 가지는 1,3-propanediolbis(4-aminobenzoate)(PDBA)를 대체 가교제로 사용하여 폴리우레탄 코팅을 제조하고 물성을 조사하였다. MOCA와 PDBA를 polyoxypropylene($M_n$=2000)에 녹이고 각종 첨가제를 혼합하여 주제부를 제조하였다. 경화제로는 NCO-terminated toluene diisocyanate prepolymer를 사용하였으며, 주제와 경화제를 실온에서 혼합하여 폴리우레탄 코팅 필름을 제조하였다. PDBA을 이용하여 제조한 폴리우레탄 코팅에서는 MOCA를 이용한 경우에 비해 초기점도가 높았고 낮은 반응성으로 인하여 가사시간도 더 길게 나타났다. 또한 인장강도와 인열강도는 MOCA를 사용할 때에 비하여 매우 낮게 측정되었다. 그러나 촉매(Pb-octoate)량을 증가시키면 PDBA의 반응성 향상으로 인하여, 건조시간, 인장강도, 신율 및 인열강도 등의 특성이 MOCA를 사용하여 제조할 때와 유사하게 나타났다. 따라서 촉매 첨가량을 증가시키거나 다른 적당한 촉매를 사용함으로써, PDBA의 반응성을 향상시킨다면, PDBA는 폴리우레탄 코팅의 제조에 있어서 MOCA를 대체할 수 있을 것으로 판단된다.

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