Hydrogels for wound dressing were manufactured using poly(vinylalcohol) (PVA) and poly( N-vinylpyrrolidone)(PVP). The hydrogels were obtained by exposing to (60)Co γ-rays after freezing and thawing of aqueous solutions of PVA and PVP to improve mechanical strength. Mechanical properties such as gelation, water absorptivity and gel strength were examined after repeating the "freezing and thawing" of PVA/PVP hydrogels, and then irradiating them at 40 kGy. The PVA:PVP ratio was in the range of 30:70 similar to 1000, and the solid concentration of PVA/PVP was 20 wt%. The gelation and strength of hydrogels were much higher when "freezing and thawing" and the irradiation process were used than when only the irradiation process was utilized. In addition, the mechanical properties of PVA/PVP hydrogels after repetition of "freezing and thawing" are discussed.

의료용 고분자로 널리 알려진 poly(vinylalcohol)(PVA)와 poly(N-vinylpyrrolidone)(PVP)를 이용하여 상처치료용 하이드로겔을 제조하였다. PVP 하이드로겔의 기계적 강도를 향상시키기 위해 PVA/PVP 혼합용액에 "freezing and thawing(동결융해)"을 반복한 후 방사선(⁶⁰Co γ-rays)을 조사하여 하이드로겔을 얻었다. PVA와 PVP의 조성비(30:70∼100:0), 동결융해의 반복횟수, PVA 분자량을 변화시키면서 PVA/PVP 하이드로겔의 겔화율, 팽윤도, 겔강도를 측정하였다. PVA/PVP 하이드로겔은 방사선 조사로만 제조되었을 때 보다 동결융해 반복 후 방사선 조사했을 때 겔화율과 겔강도가 향상되었다. 이외에 동결융해의 반복정도에 따른 물성의 특징을 논의하였다.

Keywords: hydrogels; (60)Co γ-rays; freezing and thawing; PVA; PVP