Abstract:

Hydrophylichydrophobic polyvinylpyrrolidone（PVP）semiIPNpolycaprolactone（PCL）hydrogels were prepared through free radical polymerization of N-vinyl pyrrolidone（NVP）in ethyl acetateThe melting temperature T_m kept unchanged and that was resulted from the formation of PVP-semi-IPN-PCLThe influences of some factors，such as PVP content，initiator and crosslinking agent on the swelling properties of hydrogels were investigatedIt was found that the equilibrium swelling ratio（ESR）of hydrogels increased and the bond water content in hydrogels increased with increasing PVP contentBecause of cage effect，the ESR of hydrogel with azodiisobutyronitrile（AIBN）as initiator was lower than that initiated by benzoyl peroxide（BPO）at a low initiator concentrationAs compared with NMBA crosslinking agent，hydrogels with glutaric dialdehyde（GDA）as crosslinking agent had a higher ESR at a lower concentration while had a lower ESR at a higher concentrationThe swelling kinetics of hydrogels were discussed with the Fick model and n value calculated were 0.854，0.471，0.466，0.253 with PVP content (mass)20%，40%，60%，80%, respectivelyIt could be concluded that the swelling properties of hydrogels fit the Fick model well at a proper PVP content.

摘要：

N-乙烯基吡咯烷酮（NVP）在聚己内酯（PCL）的乙酸乙酯溶液中进行自由基聚合，制备了亲水-疏水性聚乙烯吡咯烷酮（PVP）/聚己内酯（PCL）半互穿网络水凝胶（PVP-semi-IPN-PCL）。凝胶中PCL的熔融温度T_m无明显变化，而T_m吸热峰形状随PVP含量变化。凝胶平衡溶胀率（ESR）随PVP含量的升高而增大，结合水量的增大尤其显著。由于“笼蔽效应”，低浓度引发剂时，偶氮二异丁睛（AIBN）引发制备的凝胶ESR低于过氧化苯甲酰（BPO）引发剂。交联剂浓度较低时，以戊二醛交联形成凝胶的ESR较N，N-亚甲基双丙烯酰胺（NMBA）交联形成的凝胶大。浓度较高时，戊二醛交联凝胶ESR较NMBA低。PVP含量（质量）分别为20%、40%、60%、80%时，凝胶溶胀动力学Fick模型中的n值分别为0.854、0.471、0.466、0.253，说明在合适的PVP含量时，凝胶的溶胀动力学符合Fick模型。