| At present,most organic flame retardant systems have good flame retardant effects,but none of them have water solubility or low solubility;The quaternary ammonium salt flame retardant has good water solubility while ensuring the flame retardant effect,and further broadens the application space of the organic flame retardant.In this paper,a new quaternary ammonium salt MA/GTA was successfully synthesized by adjusting the pH value of the solution,The structure and properties of the modifier MA/GTA were characterized by FTIR,1H NMR and TGA;The sodium-based montmorillonite(Na-MMT)was modified by intercalation with synthetic MA/GTA and compared with unmodified montmorillonite,the structure and interlayer spacing of MA/GTA modified montmorillonite were analyzed by FTIR and XRD;The contact angle was used to test the degree of polarity improvement of montmorillonite;thermogravimetric analysis was used to test the grafting effect of MA/GTA on montmorillonite.Finally,the montmorillonite/SBR composites were prepared by two-roll mixing and molding process,and the dynamic mechanical properties and heat resistance of montmorillonite/SBR composites were tested by rubber processing analyzer and cone calorimeter.The specific analysis conclusions are as follows:1?Using melamine(MA)and 2,3-epoxypropyltrimethylammonium chloride(GTA)as the starting materials,4-pyrrolidinopyridine as the catalyst.Different yields of MA/GTA preparations were synthesized under different pH conditions.The relationship between the yield of MA/GTA and the pH shows that the maximum yield is 41.5%when the pH is 1;FTIR and 1H NMR analysis showed that the amino group on MA successfully reacted with the epoxy group on GTA,and one molecule of MA reacted with three molecules of GTA to form a structurally symmetric quaternary ammonium salt molecule;The thermogravimetric analysis of the product shows that the thermal weight loss temperature range of MA/GTA is 250??310?,which is similar to the decomposition temperature of most polymer materials of 250??350?,and the maximum weight loss rate of 15%at 300?.In addition,MA/GTA does not lose weight completely at high temperature,which should be carbonization,and the formation of carbonization can protect the organic polymer layer and further achieve the flame retardant effect.2?Organic montmorillonite was prepared by organic modification of Na-MMT with water in the laboratory using MA/GTA.FTIR and XRD data show that MA/GTA is successfully inserted into the interlayer of Na-MMT by cation exchange,so that the interlayer spacing becomes significantly larger;After modifying the montmorillonite at 80? for 4 h at 20%and 30%modifier,the interlayer spacing of montmorillonite was expanded by 20.11%and 19.58%,respectively;The contact angle test showed that the contact angle was expanded from the original 59.49°to 77.89° under the conditions of 30%,temperature of 80?,time of 4 h and pH of 7;Thermogravimetric analysis showed that montmorillonite was modified by 30%modifier at 80? for 4 h,20%modifier modified montmorillonite at 80? for 6 h,the grafting ratio of MA/GTA was 15.07%and 5.80%,respectively,which indicated that MA/GTA had a certain grafting effect on montmorillonite.3?The montmorillonite/SBR composite material was prepared by a mixing technique and a molding process;The study found that MA/GTA modified montmorillonite filled rubber can improve the vulcanization performance of montmorillonite/SBR composites,The T10 and T90 of 30%MA/GTA modified montmorillonite filled rubber were reduced to 0.65min and 1.35min,respectively,which promoted the vulcanization performance;The dynamic mechanical properties of montmorillonite/SBR composites were studied by changing the amplitude,frequency and temperature.The addition of MA/GTA can significantly reduce the loss factor of montmorillonite/SBR composites and increase the degree of crosslinking of styrene-butadiene rubber;The static mechanical properties of montmorillonite/SBR composites show that the addition of MA/GTA is beneficial to improve the tensile strength,tear strength and Shore hardness of composites;Flame-retardant and barrier tests show that the addition of MA/GTA significantly improves the heat resistance of styrene-butadiene rubber composites and significantly reduces the water absorption;Among them,the average heat release rate of 30%MA/GTA modified montmorillonite filled rubber decreased by 48.96%and the water absorption decreased by 28.96%compared with the Na-MMT filled rubber under the same part.This shows that the addition of MA/GTA can not only improve the interfacial compatibility of the composite,but also play a certain role in the peeling of the montmorillonite layer,effectively improving the flame retardant barrier properties of the montmorillonite/SBR composite system.Figure[52]table[15]references[89]... |
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