Tri-block copolypeptides of ABA type were synthesized with L-glutamic acid as A-component and L-leucine as B-component Using p-phenylenediamine as an initiator, L-leucine-N-carboxy anhydride (NCA) was polymerized in benzene for 8 days, followed by the addition of r-benzy1-L-glutamate NCA in dixane. The polymer thus obtained debenzylated by the addition of acetic acid containing 30% HBr. Permeability, hydration and critical surface tention were significantly improved compared with those of benzylated copolypeptides, and mechanical properties did not show any significant change. Clotting times of the debenzylated copolypeptides treated with 0.1% albumin solution were found to be increased by more than 10 minutes. It is concluded that membrane performance and properties of block copolypeptides possessing both hydrophilicity and hydrophobicity alternately were markedly improved compared with random copolypeptides.

친수성과 소수성 구조를 갖는 ABA형 tri-block copolypeptide를 L-glutamic acid와 L-leucine을 중합시켜 얻었다. p-phenylenediamine을 개시제로 하여 L-lencine N-carboxyanhydride (NCA)를 8일간 중합시킨 후 r-benzyl-L-glutamate NCA를 중합시켰다. 제조한 막의 투과성, 함수율 및 임계표면장력은 random copolypeptide나 homopolypeptide막보다 매우 향상되었다. 또한 debenzylation으로 기계적특성의 커다란 감소는 없었다. 0.1% albumin용액으로 처리한 후 혈액응고시간은 10분이상 길어졌다. 친수소수성을 갖는 block copolypeptide막의 투수성 및 혈액적합성이 우수함을 알 수 있었다.