环糊精二聚体与双支化两亲聚合物包合体系的构筑

将实验室自制的环糊精二聚体(66βCDsu)与双支化两亲聚合物(P(AM/BHAM/NaA))加入到水溶液中,发生包合作用构筑包合体系。研究该体系的增黏及溶液流变学特性,并采用荧光光谱仪、扫描电镜及差示扫描量热仪等研究包合体在溶液中的包合机制及结构形态。结果表明,由于P(AM/BHAM/NaA)中1个疏水单体中存在2个疏水基团(正十六烷基和苄基),因此环糊精与疏水单体BHAM最大摩尔包合比为2∶1,完全包合后溶液中没有游离态疏水基团,因此溶液不存在临界聚集浓度(CAC)。当环糊精与BHAM摩尔包合比为1∶1,体系存在明显的CAC,这是由于环糊精首先包合双支化疏水单体中的苄基形成包合体,而正十六烷基依然存在于水溶液中。当P(AM/BHAM/NaA)浓度为800mg/L时,该体系中存在2种聚集方式,一种是疏水基团的疏水缔合;另一种是包合作用。通过扫描电镜证明了不同体系的微观聚集形态。

Inclusion Mechanism of the Cyclodextrin Dimers and Double Branched Amphiphilic Polymer

The cyclodextrin dimers 66βCDsu mixed with double branched amphiphilic polymer P(acrylamide/N-benzyl-N-n-hexadecyl acrylamide/sodium acrylate) (P (AM/BHAM/NaA)) in the solution to form the inclusive system The viscosifying capacity and rheological properties of the inclusive system were studied and through fluorescence spectrophotometer,SEM and DSC,the inclusion mechanism and structure of inclusive systems were studied to establish the intrinsic relationships between microstructure and rheological properties.The results show that the viscosity of inclusion complex solution significantly increases under the concentrations of amphiphilic polymers which are less than the critical aggregation concentration (CAC).The maximum viscosity for multi-sticker amphiphilic polymer complexes is got at the mole ratio of CD/BHAM 2∶ 1.The UV Vis absorbance verifies that the mole ratio of the inclusion complex between CD and BHAM is 2∶1 stoichiometry.Because of the inclusion association between the host and guest polymers,the solution of inclusion complex has much higher viscoelasticity even under the low amphiphilic polymer concentration.When the mole ratio of CD to BHAM is 1∶1,the CAC of the inclusion complex solution still remains.Furthermore,above the CAC,two types of associations,inclusion association and intermolecular hydrophobic association,can occur in the complex solution.Using the Carreau model,the rheological curve was fitted and it indicates that the inclusive system (n (CD)∶n (BHAM) =2∶1) has the highest zero-shear rate viscosity,because the complete inclusion make the system form an intensity network structure.And theseinteractions were also verified by SEM.