Polytetrahydrofuran/Clay Nanocomposites by In Situ Polymerization and “Click” Chemistry Processes

Abstract

Polytetrahydrofuran (PTHF)/clay nanocomposites were prepared by two routes: in situ cationic ring opening polymerization (CROP) and a method involving "click" chemistry. In the first method, PTHF chains were grown from the surface of the organo-modified montmorillonite clay by CROP of tetrahydrofuran (THF) through the hydroxyl functions of the clay by using trifluoromethanesulfonic anhydride, in the presence of 2,6di-tert-butylpyridine as proton trap and dichloromethane as solvent. The polymerizations were affected by the clay content ratios. The living characteristics of the polymerization were demonstrated by the semilogarithmic first order kinetic plot. In the second method, CROP of THF has been performed independently to produce alkynefunctionalized PTHF and the obtained polymers were subsequently anchored to azide-modified clay layers by a "click" reaction. The exfoliated polymer/clay nanocomposites obtained by both methods were characterized and compared by X-ray diffraction spectroscopy, thermogravimetric analysis, and transmission electron microscopy. Compared to the virgin polymer, the nanocomposites exhibited improved thermal stabilities regardless of the preparation method. However, the nanocomposites prepared by the "click" chemistry approach appeared to be thermally more stable than those prepared by in situ polymerization. Moreover, the "click" chemistry method also provided better exfoliation.

Synthesis, Characterization and Photoinduced Cross-linking of Functionalized Poly(cyclohexyl methacrylate) Copolymer/Clay Nanocomposite as Negative Image Patterning Material

“…Quite recently, we reported conceptually different approaches based on "click" reactions [16] or supramolecular association such as hydrogen bonding [17] to prepare the polymer/clay nanocomposites. In both cases, exfoliation is rooted in the functional units of the intercalant that readily interact with the antagonist groups of the preformed polymers.…”

Synthesis, characterization, and hydrolytic degradation of graft copolymers of polystyrene and aliphatic polyesters

“…[33,34] Many examples of click reactions involving macromolecules were reported. In this laboratory, we have focused on the use of such click reactions for the synthesis of various macromolecular architectures [34][35][36][37][38][39][40][41] and functionalization of polymers [42][43][44][45][46][47], microspheres [48], clays [49,50], and silsesquioxanes [51] with thermal-, photo-, and electro-active groups.…”

Photoinduced grafting of polystyrene onto silica particles by ketene chemistry

“…47,48 The synthesis of polymer/silica nanocomposites has recently received increased attention due to their excellent physicochemical properties with respect to their unmodified polymer analogs. [49][50][51][52][53][54] They find practical applications in thermal insulation, 55 bioactive supports, 56 paints, 57 drug delivery systems, 58 and composite materials. 59,60 Supporting polymers at the surface of silica nanoparticles can be achieved by two different approaches.…”