Poly( N isopropylacrylamide)/poly(vinyl alcohol)(PNV) hydrogels were prepared by repetitive freezing and thawing. This kind of hydrogels was formed through physical crosslinking, i.e. hydrogen bonds during the freezin...Poly( N isopropylacrylamide)/poly(vinyl alcohol)(PNV) hydrogels were prepared by repetitive freezing and thawing. This kind of hydrogels was formed through physical crosslinking, i.e. hydrogen bonds during the freezing process. The swelling ratio and deswelling/reswelling kinetics were measured gravimetrically and this novel hydrogel exhibits a temperature sensitivity. This hydrogel may be useful both in biomedical and biotechnological fields.展开更多
In this contribution, we reported a novel approach to crosslink poly(ε-caprolactone)(PCL) via supramolecular hydrogen bonding interactions. First, a series of octa-armed poly(ε-caprolactone) stars with polyhedral ol...In this contribution, we reported a novel approach to crosslink poly(ε-caprolactone)(PCL) via supramolecular hydrogen bonding interactions. First, a series of octa-armed poly(ε-caprolactone) stars with polyhedral oligomeric silsesquioxane(POSS) cores were synthesized via the ring-opening polymerizations. Thereafter, the arm ends of organic-inorganic star-shaped PCLs were reacted with 2-(6-isocyanatohexylaminocarbonylamino)-6-methyl-4[1 H]-pyrimidinone to obtain 2-ureido-4[1 H]-pyrimidone(UPy)-terminated PCL stars.Notably, the UPy-terminated PCL stars were physically crosslinked, which was evidenced by means of dynamic mechanical thermal analysis(DMTA) and rheological analysis. Owing to the formation of the physically-crosslinked networks, the organic-inorganic PCL stars displayed significant shape memory properties with about 100% of shape recovery, which was in marked contrast to the PCL stars without UPy termini.展开更多
文摘Poly( N isopropylacrylamide)/poly(vinyl alcohol)(PNV) hydrogels were prepared by repetitive freezing and thawing. This kind of hydrogels was formed through physical crosslinking, i.e. hydrogen bonds during the freezing process. The swelling ratio and deswelling/reswelling kinetics were measured gravimetrically and this novel hydrogel exhibits a temperature sensitivity. This hydrogel may be useful both in biomedical and biotechnological fields.
基金financially supported by the National Natural Science Foundation of China(Nos.51133003,21274091,and21774078)
文摘In this contribution, we reported a novel approach to crosslink poly(ε-caprolactone)(PCL) via supramolecular hydrogen bonding interactions. First, a series of octa-armed poly(ε-caprolactone) stars with polyhedral oligomeric silsesquioxane(POSS) cores were synthesized via the ring-opening polymerizations. Thereafter, the arm ends of organic-inorganic star-shaped PCLs were reacted with 2-(6-isocyanatohexylaminocarbonylamino)-6-methyl-4[1 H]-pyrimidinone to obtain 2-ureido-4[1 H]-pyrimidone(UPy)-terminated PCL stars.Notably, the UPy-terminated PCL stars were physically crosslinked, which was evidenced by means of dynamic mechanical thermal analysis(DMTA) and rheological analysis. Owing to the formation of the physically-crosslinked networks, the organic-inorganic PCL stars displayed significant shape memory properties with about 100% of shape recovery, which was in marked contrast to the PCL stars without UPy termini.
