대학원생 구두발표(토론III): 콜로이드 및 분자 자기조립의 원리와 응용
[OD3-2]
우수논문발표상 응모자Crystallization-Driven 1,000-Fold Stiffness Jump near Physiological Temperature in PEGDA Networks
발표자최서진 (서울대학교)
연구책임자김정욱 (서울대학교)
Abstract
It is well known that mechanical properties of PEGDA network and crystallization of PEG units depend on the molecular weight(Mw) between crosslinks (Mc). Covalent junctions constrain PEG chains, reducing melting temperature (Tm) and crystallinity, whereas dangling chains remain more mobile and crystallize more readily. Here, we synthesized networks using 1k PEGDA, a dithiol chain extender, and a 4-arm thiol crosslinker, varying their molar ratios to tune Mc. DSC provided crystallization temperature (Tc), Tm, and transition enthalpy to quantify crystallinity. Temperature-sweep rheology showed an ~3-order increase in storage modulus near Tc, evidencing crystal-derived physical crosslinks.
Overall, the PEGDA networks exhibited increasing Tm with increasing PEGDA Mw, and Tc shifted upward toward Tm as Mc increased. Based on these thermomechanical characteristics, we propose this crystalline PEGDA network as a candidate material for a tough bandage intended for tendon repair.