title: Effect of Ni cations and microwave hydrothermal treatment on the related properties of layered double hydroxide-ethylene vinyl acetate copolymer composites.
abstract: The effect of Ni cations and synthetic methods on the crystallinity, morphology, thermal stability and hydrophobic properties of carbonate-containing layered double hydroxides (LDHs) was investigated. The conventional hydrothermal treatment (CHT) and microwave hydrothermal treatment (MHT) methods were used to synthesize LDHs. The microwave treatment LDHs (MgAl-MHT and NiMgAl-MHT) have higher crystallinity and smaller crystal sizes than the conventional hydrothermal treatment LDHs (MgAl-CHT and NiMgAl-CHT). IR results indicate that the interactions of both OH(-)-CO(3)(2-) and CO(3)(2-)-CO(3)(2-) in NiMgAl-MHT are weaker. Furthermore, the thermal decomposition of OH(-) and CO(3)(2-) in the NiMgAl-MHT sample occurred earlier and faster than that of other LDHs. The contact angle values indicate that NiMgAl-MHT has the highest hydrophobicity. The influences of the LDHs on the thermal degradation and flame retardance of ethylene vinyl acetate copolymer (EVA)-LDH composites have also been studied in detail. NiMgAl-MHT has the more homogeneous nano-dispersed layers in EVA matrix. All composites enhance the thermal stability compared with the pure EVA because of the release of H(2)O and CO(2). Flame retardance of NiMgAl-MHT-EVA was obviously higher than that of the pure EVA and other composites.
authors.affiliation: Heilongjiang Key Laboratory of Molecular Design and Preparation of Flame Retarded Materials, College of Science, Northeast Forestry University, Harbin, PR China. liliwangsh@gmail.com
authors.forename: Lili
authors.initials: L
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Li
authors.forename: Mingfei
authors.initials: M
authors.lastname: Yang
authors.forename: Chunxia
authors.initials: C
authors.lastname: Chen
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000085:Acetates / Q000737:chemistry; D002254:Carbonates / Q000737:chemistry*; D002412:Cations / Q000737:chemistry; D003460:Crystallization; D057927:Hydrophobic and Hydrophilic Interactions; D006878:Hydroxides / Q000737:chemistry*; D008872:Microwaves; D009532:Nickel / Q000737:chemistry*; D011095:Polyethylenes / Q000737:chemistry*; D011145:Polyvinyls / Q000737:chemistry*; D013696:Temperature
chemical_list: D000085:Acetates; D002254:Carbonates; D002412:Cations; D006878:Hydroxides; D011095:Polyethylenes; D011145:Polyvinyls; D009532:Nickel