Study On The Preparation, Morphology And Properties Of Polymer/organic Modified Laminated Inorganic Nanocomposites

PartⅠ:Synthesis and properties of polymer/polystyryl modified montmorillonites nanocompositesThe contents of partⅠincluding the following:1 Preparation and characterization of polystyryl modified montmorillonitesThree polystyryl quaternary ammonium salts have been synthesized from the reactions of trimethylamine with chloromethyl polystyrenes which were prepared by three different methods:free-radical co-polymerization,chloromethylation of polystyrene and anionic polymerization.Then the polystyryl-modified montmorillonites(OMMT) have been obtained from the ion exchange of sodium ions in the montmorillonites with polystyryl quaternary ammonium salts.The polystyryl quaternary ammonium salts have been characterized using GPC,FT-IR,TGA,XRD,~1H NMR,and TEM.TGA data indicated that the ammonium salts prepared by anionic polymerization and their montmorillonites(OMMT)complexes have higher initial degradation temperatures.The structures with different molecular weight polystyryl modified montmorillonites were studied by XRD and TEM.The experimental results indicated that there were strong association between ratio of molecular weight to charge for the quaternary ammonium salts and the exfoliation degrees of their montmorillonite complexes,the higher M/Z of quaternary ammonium salts is,the larger the interlayer spacing of montmorillonites is.2 Synthesis and properties of nylon-6/OMMT nanocomposites Nylon-6/OMMT nanocomposites have been prepared by melt blending with nylon-6 and polystyryl quaternary ammonium salts with different molecular weight by anionic polymerization.The effects of the molecular weight of polystyryl quaternary ammonium salts and the contents of modified montmorillonites based on thermal performance and mechanical properties of nylon-6/OMMT nanocomposites have been investigated.The structures and thermal performances of nylon-6/OMMT nanocomposites have been characterized by XRD,TGA and HDT,and their mechanical properties have also been tested.The experimental results from XRD,TGA,HDT and mechanical testing have indicated that: (a)The crystallization behavior of nanocomposites have been changed due to the addition of OMMT,one could observe the presence ofγ-type crystal of nylon-6;(b)a loading of 3 wt%montmorillonite which was modified by polystyryl quaternary ammoniums with a molecular weight of 2500 has shown remarkable thermal stability and mechanical properties compared to that of pure PA6,the initial degradation temperature of nanocomposites were increased by 36℃,42℃and the tensile strength,bend strength and tensile modulus were improved by 13%,22%,50%,respectively;(c)The nanocomposites with 3 wt%MMT have better properties when the number-average molecular of polystyryl quaternary ammonium salts is equal to 1400, among which,the initial degradation temperature of nanocomposites were increased by 32℃,33℃and the tensile strength,bend strength and tensile modulus were improved by 11%,18%,40%, respectively.3 Synthesis and properties of polyproplylene(PP)/OMMT nanocompositesPP/OMMT nanocomposites have been prepared by melt blending with PP and polystyryl modified montmorillonites(Mn=2500).The effects from the contents of modified montmorillonites on thermal performance and mechanical properties of PP/OMMT nanocomposites have been investigated.The structure and thermal performance of PP/OMMT nanocomposites have been characterized by XRD,TGA and HDT,and their mechanical properties have also been tested.XRD results indicated thatβ-type crystal was present in the nanocomposites due to addtion of montmorillonites.TGA and HDT data indicated that there OMMT was no significant improuement in the thermal properties of nanocomposites;The nanocomposites with 2 wt%MMT have shown better mechanical properties,the tensile strength,tensile modulus and izod impact energy was improved by 13%,12%,20%, respectively.4 Synthesis and properties of polystyene(PS)/OMMT nanocompositesPS/OMMT nanocomposites have been prepared by melt blending with PS and polystyryl modified montmorillonites(Mn=2500).The effects from the contents of modified montmorillonites on thermal performance and mechanical properties of PS/OMMT nanocomposites have been investigated.The structures and thermal performances of PS/OMMT nanocomposites have been characterized by TGA and HDT, and their mechanical properties have also been tested.TGA results indicated that the initial degradation temperature of nanocomposites at a MMT loading of 3 wt%was increased by 18℃.But the mechanical properties decreased with addition of MMT except for tensile modulus.PartⅡ:Synthesis and properties of epoxy acrylates /reactiveα-zirconium phosphate nanocompesites by photopolymerization reactionN-octadecyl-4-vinylbenzenaminium chloride(OVBAC),a functionalized surfactant,containing a C=C double bond,have been synthesized to prepare a reactiveα-zirconium phosphate(α-ZrP)through ion exchange pre-intercalated methl amine inα-ZrP.Then UV curable nanocomposites were obtainded through epoxy acrylates reinforced with O-α-ZrP.These UV-cured nanocomposites have been characterized using XRD,TEM and mechanical testing.XRD and TEM results have shown intercalated or partial exfoliated structures for all the samples.The mechanical properties of UV-cured nanocomposites were significantly enhanced due to the presence of O-α-ZrP.