Abstract: By using N-isopropylacrylamide (NIPAm) as monomer,polyethylene glycol (PEG) as porogenic agent,poly (methylacrylic acid-beta hydroxy ethyl ester)(PHEMA) as second network substance,the thermosensitive porous semi-interpenetrating network hydrogels are prepared.Effects of different molecular weight porogenic agents (PEG1000,PEG1500,PEG2000),dosage of porogenic agent,crosslinker dosage and mass ratio of PHEMA/NIPAm on hydrogels structure and properties are investigated.The prepared hydrogels are characterized by FT-IR,SEM,DSC,BET and gravimetric method.The optimal preparation conditions are:m(PHEMA)/m(NIPAm)=0.25 (weight ratio),crosslinker dosage accounting 2.67% of total monomer,PEG molecular weight in the range of 1 000-2 000,and PEG dosage accounting 40% of total monomer.It is detected that pore sizes of hydrogels are 10-20 microns.At room temperature 20℃,the hydrogels can absorb more than 60% of water in 20 minutes,and can reach swelling equilibrium in 90 minutes.The hydrogels can lose more than 90% of water at 50℃ in 10 minutes.The lower critical solution temperature is about 35.8℃.
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