Preparation Of High-effective Environment Friendly Flame Retardant And Its Flame Retardancy In Composites

With the development of flame retardancy technology and the restriction of halogen-containingflame retardant, it is awefully urgent to develop high-effective and environment friendly flameretardant system. Additionally, energy shortage is another barrier to social development. Now it offersa facile solution to develop a novel energy storage system. In the paper, we synthesized abiodegradable hyperbranched poly(phosphamide ester) and an amorphorous nickel phosphate (NiPO).After that, we melting blended the as-prepared HBPE and NiPO with PLA to prepare flame retardedPLA composites.To begin with, ethanolamine and phosphorus oxychloride were used to synthesize AB2-typemonomer and then furthermore to prepare HBPE through one-pot method. The structure and thermalstability property were characterized using FTIR,1H-NMR spectrum,31P-NMR spectrum, GPC andTGA. Apart from it, amorphorous NiPO micro-particle was synthesized through hydrothermalapproach using diammonium phosphate and nickel nitrate hexahydrate and then analyzed by XPS,FTIR, XRD and TGA.Afterwards, HBPE and NiPO were melting blended with PLA to prepare the flame retarded PLAcomposites. PLA composite with only2wt%HBPE exhibited excellent flame reterdancy (LOI=33%and UL-94V-0rating) and10wt%HBPE imparted PLA composites LOI value of43%and UL-94V-0rating. The incorporation of10wt%HBPE obviously increased CO production rate (COP) andprolonged time to ignition (TTI) in CCT. Furthermore the intrinsic thermal stability of PLA compositeswas enhanced with the addition of HBPE. Tgof PLA composites decreased slightly, which indicatedthe partial miscibility between PLA and HBPE. Finally, the accelerated nucleation effect was alsodetected in PLA composites using polarized optical microscopy (POM) observation.Meanwhile, PLA composite with only2wt%NiPO powder exhibited excellent flame retardancy(LOI=27.5%and UL-94V-0rating). A slightly increased CO production rate and significantly decreased total smoke production (TSP) were found with the addition of NiPO into PLA in CCT.Moreover, in the CCT and PCFC test, it showed that HRR of the PLA composites was higher in theearly stage and lower in the late stage than that of pure PLA. Additionally, the intrinsic thermalstability was enhanced significantly with NiPO into PLA composites. Meanwhile NiPO could alsoimprove the crystallization property of PLA composites.Meanwhile, a novel shape-stabilized phase change material then was prepared via in-situ sol-gelapproach, consisting of paraffin as latent thermal energy material and3,9-di-(triethoxysilylpropyl)-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5,5]undecane-3,9-dioxide (SPDPT) as the sol-gel precursor. Theparaffin composites showed latent thermal melting enthalpy as much as99.7J/g. And when theterperature was higher than melting point of pure paraffin, paraffin composites showed no liquidleakage probably due to the special morphology of cylinder and droplet in matrix. IPDT analysisshowed the intrinsic thermal stability was hugely increased. The char residue content at600℃wasremarkedly higher with addition of silsesquioxane in composites. PCFC test demonstrated obviouslyenhcanced flame retardancy.