| This dissertatoin is composed of two parts. First, study on the intercalated nanocompositeofepoxy and clay, second, study on intercalated nanocomposites of high performance plasticsand clayIn the first part, intercalation and exfOliation behavior of organoclays in epoxy resin hasbeen investiSated. It was fOund that the organoclays were easy to be intercalated by epoxyoligomer to form a stable epoxy/clay intercalated hybrid. Under appropriate conditions theclny was able to be further exfoliated as the epoxy resin was cured, as a result, exfoliatednanocomposites were obtained. lt was also found that the exfoliating ability of theorganoclays was basically determined by the nature of the organoclays and the curing agentused. The exfoliation mechanism was discussed. The results revealed that if the organoclayscould be exfoliated at all, the exfOliation would complete before the gel point of epoxy resinreached. The exfoliation of clay competes with the curing of the extra-gallery resin. If theintra-gallery epoxy cured faster, it will drive the clay to exfOliate befOre the eatra-gallery-epoxy resin reaches its gel point. Otherwise the eatra-gallery resin will gel first and block thefurther exfOliation of the clay So the factors facilitating the curing reaction of intra~galleryepoxy would enhance the exfoliation of the clays.The mechanical properties results indicated that the exfoli8tion of clay in epoxy resin wasessential for better properties of the nanocomposites. As the content of the clay was about2wt%, the properties were oPtimal. Compared with pure epoxy resin, the impact strengthincreased about 50%, the fiexural Strength rose 5~l0%, the moduluds increased with thecontent of the clay linearly. The heat distort temperatUre increased l5C, but the glasstransition temperature of the nanocomposites chan8ed not much.Rubbers are widely used as tougheners of epoxy resin. However, as the toughness isincreased, the strength, stiffoess and heat resistance of the materials are compromised to mucheatent because of the weakness of the rubber TO solve this problem, a new approach wasintroduced in this paper Some clay is added into the rubber before it is used to toughen theepoxy. By fOrming epoxy/rubber/clay three-phase system, the comprehensive p,,p,rtie, areimproved.'In the sde6nd part, the intercalation and exfOliation of organoclay in high perfbrmanceplastics were investigated. As the high pefformance plastic resins PEK-C, PES, PEI and PSUwere mixed with organoclay TJl in solution, the XRD results revealed that the PEK-C andPES were very easy to intercalate into the clay and drove the cIay to exfoliate, as a result,exfoliated polymer/clay nanocomposites were obtained. The interlayer distance of the clay inthe nanocomposite reached 10-l5nm. On the contrary PEI and PSU could not intercal8te intothe clay. The possible reasons caused these different results might be that the interactionbetWeen the fOrmer two polymers and clay were strong While the interaCtion between thelatter two polymers and clay were weak. The glass transition temperature T,s of PEK-C/clayand PES/clay nanocomposites were 2l0'C and 229oC, much lower than that of pure PEK-Cand PES, Which were 227C and 237oC, respectively. But the on-set temper8ture ofdecomposition T, of PEK-C and PES rose from 469'C to 507'C and from 5l4C to 579'Cafter mixed with clay, increased 38'C and 65C, respectively. The mechanica1 properties ofthe PEK-C/clay nanocomposite are worsen too aller inclusion of the clay For the polymerPEI and PSU, which could not intercalate into the clay both their T, and T, changed littleafter mixed with the clay The positron axinihilation life sPectroscopy results indicated thatlarger free volumes formed as PEK-C combined with clay which was supposed to beresponsible for the decreases of its T,' In the PEK-C/clay nanocomposites, the clay andpo1ymer mixed on molecular level, but their shape are not compatible and they ca...
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