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Study On Preparation, Characterization And Properties Of Polyazomethine/nylon-6 Composites By In-situ Polymerization

Posted on:2004-09-26Degree:DoctorType:Dissertation
Country:ChinaCandidate:H L DingFull Text:PDF
GTID:1101360092980621Subject:Materials science
Abstract/Summary:PDF Full Text Request
In this paper, three different kinds of polyazomethines(PAM)/nylon 6 in situ polymerization composites were prepared using the process of monomer casting. Their structures, thermal properties and also mechanical properties were analyzed. Isothermal and non-isothermal crystallization behaviors were also investigated.The results of FT-IR, UV spectrum, WAXD and SEM indicated that rigid rod polymer polyazomethines were polymerized in the composites. The addition of PAM changed the crystallization morphology and apparent crystallinity of the composites, but did not change the basal αcrystal form. The mechanism of reinforcement and toughness were studied through the characterization of microstructure with TEM and SEM. The results showed thermal and mechanical properties of the composites excelled the pure nylon. When the contents of PAM amounts to 5%, Tg was increased 6-9 oC; thermal loss temperature curves shifted toward higher temperature, so resistance to thermal was obviously improved; tensile strength was increased 27-36%,while impact strength 9-117%.The studies of crystallization kinetics of the composites indicated that isothermal and non-isothermal crystallization behaviors could be described by Avrami equation, and the Avrami exponents were between 2 and 3. So it could be concluded that the mode of crystallization growth was mainly three dimensions spherulity and two dimensions dish.In the dry sliding experiments of composites, friction coefficients decreased with the increase of load. Plastic deformation happened in the worn surface where Fe element was found, so PAM micro-fiber supported part of the load and prevented the further deformation. On the condition of high speed and high load, the worn surface of PAM1/nylon 6 composites was nearly melted and formed comparative uniform transfer on the surface of steel, which accounted for the rather low wear mass loss. The infrared analysis showed that the a small quantity of transition of crystal form from α into γ of nylon and its composites happened during the friction because of the high temperature and strong sheering strength.
Keywords/Search Tags:polyazomethines, nylon 6, in situ polymerization composites, rigidrod polymer, crystallization behaviors, dry friction
PDF Full Text Request
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