Study On Preparation And Properties Of Thermosetting Resin/Montmorillorite Nanocomposites

In this thesis, organic-montmorillorite (Org-MMT) was obtained - by an ion-exchange reaction between Na+-montmorillorite (Na+-MMT) and alkyl ammonium bromide, leading to increase the basal spacing of montmorillonite. XRD analysis indicated that alkylammonium ions had already exchanged with Na+ ions in Na-montmorillonite and long alkyl-chains had entered into the gallery of montmorillorite. Thermosetting resin/Org-MMT nanocomposite, including exopy resin/Org-MMT and phenolic resin/Org-MMT, were prepared by in situ intercalation polymerization, and the intercalation and exfloliation behaviour of them were characterized by X-ray diffraction (XRD), Dynamic Mechanical Thermal Analysis (DMTA), and Different Scanning Calorimetry (DSC). The work was composed in five parts:(1) Epoxy resin /Org-MMT/diethylenetriamine(DETA), epoxy resin/Org-MMT/ imidazole(MZ) and epoxy resin/Org-MMT/tung oil anhydride(TOA) nanocomposites were prepared by in situ intercalation polymerization. XRD analysis showed that epoxy molecules could insert into the interlayer of organic-montmorillonite, leading to increasing of basal spacing of montmorillonite. The type of formed nanocomposite was depended on the kind of curing agent used: intercalated nanocomposite was formed for curing agents of DETA or MZ, and exfoliated nanocomposite was obtained for curing agent of TOA.(2) XRD analysis showed that phenolic resin molecules could insert into the interlayer of organic-montmorillonite, but there are some differences of the behavior of intercalation between thermosetting phenolic resin and thermoplastic phenolic resin.(3) The cure kinetics parameters of epoxy resin /Org-MMT/DETA, epoxy resin/Org-MMT/TOA and epoxy resin/Org-MMT/MZ nanocomposites were investigated by Differential Scanning Calorimetry (DSC). Some kinetics parameters including the reaction order and activation energy were caculated with Kissinger method. The curing dynamic parameters of epoxy resin/Org-MMT/MZ nanocomposites were obtained by the modified Avrami expression and Autocatalytic expression. The curing energy of epoxy resin/Org-MMT/TOA systems with different degrees of curing were obtained by Flynn-Wall-Ozawa Method.(4) The glass transition temperature, determined by DMTA, was response to the epoxy resin cured extragallery for epoxy resin/Org-MMT/diethylenetriamine nanocomposite, and the value of the glass transition temperature was in relation to the curing temperature, and addition of Org-MMT led to the disappearance of the a' peak of loss tangent of the nanocomposite. However, the glass transition temperature of exfoliated nanocomposite, epoxy resin/Org-MMT/tung oil anhydride, decreased as the increase of Org-MMT content.(5) The tensile-shear strength of unitary-aluminum piece and tensile strength of mushroom-sample of EP/Org-MMT/ DETA nanocomposites with the different Org-MMT were obtained in this thesis.