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Preparation And Properties Of Modified MCA/Nylon 6 Halogen-free Flame Retardant Composites By In-situ Polymerization

Posted on:2016-05-07Degree:MasterType:Thesis
Country:ChinaCandidate:L Y WangFull Text:PDF
GTID:2191330464451779Subject:Materials engineering
Abstract/Summary:PDF Full Text Request
A large amount of water is used and waste water is discharged by conditional preparation method for melamine cyanurate(MCA), the presence of MCA in nylon 6 composites leads the mechanical properties and wick effect. To overcome these shortages caprolactam was used as a reaction medium to prepare MCA, and silica sol was added and MCA was modified, In situ polymerization was carried out and modified MCA/nylon 6 non-halogen flame retardant composites were prepared. The whole preparation process was environmental friendly. When flame retardants was 7wt% the flame retardant property of composite reached UL 94 V-0 rating and the mechanical properties were improved. The optimum condition for preparation modified MCA and nylon 6, the relationship between the structure and preparation condition for MCA and nylon 6, the flame retardant mechanism of flame retardant nylon 6 composites were all investigated in detail. Tetraethyl orthosilicate could be hydrolyzed in molten caprolactam, when the temperature was 90 ℃, reaction time was 4 hours and the loading of silica sol is 10wt% to MCA, the modified MCA can reach optimum properties. When the polymerization was carried out at 250 ℃ and 0.6 MPa for 6 hours, and then at 250 ℃and-0.1 MPa for 2 hours, high molecular weight nylon 6 was obtained. By this method, the particle size of modified MCA could be controlled and the surface property of MCA was improved, the evenly dispersion of MCA in nylon 6 matrix was obtained, besides, the nylon 6 had high molecular weight. Compared to pure nylon 6 the tensile strength of composites increased by 3%, limited oxygen index increased by 45.9%(reached 35). Both the condensation phase and gas phase flame retardant mechanism were taken effect during the flame retardant process. The results would be helpful for industrial production of non-halogen flame retardant nylon 6 composites.
Keywords/Search Tags:nylon 6, melamine cyanurate, in situ polymerization, non-halogen flame retardant
PDF Full Text Request
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