Preparation, Structure And Property Studies Of A Novel Polymer/Mesoporous Molecular Sieve Composite Materials

Mesoporous molecular sieve (MMS) has attracted a great deal of interest for their particular characteristics, such as large internal surface area, uniform framework and easily controlled pore diameter. Thus, some of their applications including catalysts, sorbents, and separating materials were expected. Furthermore, some researchers published findings on the host-guest polymerization of organic molecules in such inorganic mesoporous materials. However, few reports focus on the polymer/MMS composites based on the special structure of the MMS and used it as a kind of inorganic filler. In this work, two kinds of polymer/MMS composites (PMMA/MCM-48, PET/MCM-41) were prepared by in-situ polymerization, in which two types of MMS prepared by us were used. According to the structural feature and improved physical properties of these composites, a novel structural model named as "Inorganic-Organic Interpenetrating Network" (IOIN) was proposed to interpreted these results.In this work, two kinds of MMS were prepared under different conditions. MCM-41 was synthesized under ultrasonic in acidic media, and variousreaction conditions were investigated in order to obtain a most appropriate method. MCM-48 was synthesized in basic media at room temperature to get a satisfied structure. Both these two kinds of MMS have large internal surface area, large volume and narrow pore-size distribution.Aim to insert the monomers into the channels of MMS, the mesoporous particles were dried and vacuumed absolutely before using. Then monomers containing initiators were injected into the reactor and mixed with MMS particles under ultrasonic at room temperature. Finally, the in-situ polymerization was performed at proper temperature and pressure. The final products were PMMA/MCM-48 and PET/MCM-41 composites.The composite particles extracted from proper solvent show small residual pore volume in nitrogen sorption isothermal, an obvious drop in sample weight in thermogravimetric trace, and no obvious glass transition in DSC curve. It is believed that the polymer surely exists in the mesopores, and an interaction between the pore-wall and the molecular chains, as well as the severe confinement of the mesoporous channel, prevents the movement of the polymer segments within the channels.The MMS particles show an even distribution in the polymer matrix of polymer/MMS composite. Due to the existence of MMS in polymer, the composites show different characteristics in structure and properties. The composite shows much higher glass transition temperature and higher thermal stabilization with increasing MMS content. The tensile strength and bending strength increase with a proper content of MMS in the polymer matrix. The...