Improving the flame retardancy of polyamide 6 by incorporating hexachlorocyclotriphosphazene modified MWNT

A nitrogen‐, phosphorus‐ and chlorine‐containing flame retardant, hexachlorocyclotriphosphazene (HCTP), has been covalently grafted onto the surface of multi‐wall carbon nanotubes (MWNT) to obtain MWNT‐HCTP. Polyamide 6 (PA6)/MWNT composites were then prepared via melt compounding. The flammability of PA6/MWNT composite was characterized by cone calorimetry, limiting oxygen index (LOI) and UL‐94 tests. The results showed that peak heat release rate of samples containing 3 wt% MWNT‐HCTP was only 460 kW/m², which decreased by 35.2% compared with that of a neat PA6 sample. The LOI value was increased from 22.7% to 26.5%, and UL‐94 test performance was also significantly improved by the presence of MWNT‐HCTP. Scanning electron microscope (SEM) and optical microscope analysis showed that modified MWNT had a better dispersion and compatibility in PA6 than unmodified MWNT. The composition of residue chars and volatile products was investigated by SEM/energy dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric‐FTIR, respectively. It was proposed that grafted HCTP was mainly functioned in the condensed phase, where P, N can synergistically promote char formation and Cl element can catch free radicals to terminate the chain reaction during combustion of the PA6 composite. Copyright © 2014 John Wiley & Sons, Ltd.     

一种无计有机聚合物中间体——六(甲基丙烯酸羟乙酯)三聚膦腈的合成

六氯三聚膦腈;一种无计有机聚合物中间体——六(甲基丙烯酸羟乙酯)三聚膦腈的合成     

三聚磷腈的制备新工艺

三聚磷腈是生产聚磷腈和环磷腈的主要原料 ,通过采用有机亲核试剂取代活性氯原子 ,可以生成多种化合物 ,具有多种用途 ,可以用作新型高效阻燃剂、侧链液晶、特种橡胶和电子材料等 [1,2 ] .自 1 960年 Lund等以五氯化磷和氯化铵为原料合成出三聚磷腈以来 ,主要集中在原料的选择和产品的分离提纯上 .可以选用 NH3和 HCl代替NH4 Cl作为原料 [3] ,也可选用 PCl3和 Cl2 代替PCl5作为原料 [4 ] ,使产品的收率得以提高 ;还可选用不同的催化剂来进行催化反应 [5] ,缩短了反应时间 .我国目前三聚磷腈的合成 ,大多数仍然采用传统的以五氯化磷和…     

正交法研究六氯环三磷腈的合成

利用正交法研究了六氯环三磷腈的合成反应;针对较典型的四个因素,分别取四水平L16(45)正交表进行正交试验,确定了合成目标产物的主要影响因素和优化反应条件.结果表明,先将2/3的固体五氯化磷与2%无水氯化锌和30%吡啶(以五氯化磷物质的量计)混合,再缓慢滴加入剩余的五氯化磷氯苯溶液,最高产率可达84%以上;方差分析结果...     

Synthesis of Hexakis-(4-tetrazolylphenyloxy)cyclotriphosphazene and Its Alkylonitrile Derivative

Tetrazoles were introduced into cyclotriphosphazenes to obtain hexakis-(4-tetrazolylphenyloxy)cyclotriphosphazene (2) in good yield (88.9%) by reacting hexakis-(4-cyanophenyloxy)cyclotriphosphazene (1) with sodium azide in N,N-dimethylformamide (DMF) in the presence of NH₄Cl as a catalyst. Its alkylonitrile derivative, hexakis-(4-cyanoethyltetrazolylphenyloxy)cyclotriphosphazene (3), was prepared by the reaction of 2 with acrylonitrile in acetonitrile, using triethylamine as a catalyst.

Synthesis of ansa-o-carboranylenecyclotriphosphazene

The previously unknown ansa-o-carboranylenecyclotriphosphazene was obtained in a 15% yield by the reaction of bis(hydroxymethyl)-o-carborane with hexachlorocyclotriphosphazene; its structure was confirmed by¹H and³¹P NMR and IR spectroscopy methods and by mass spectrometry. The thermal properties of the obtained compound were studied.A. N. Nesmeyanov Institute of Heteroorganic Compounds, Russian Academy of Sciences, 117813 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 177–179, January, 1992.     

含双螺环三聚磷腈单元的苯并噁嗪树脂的结构和热稳定性

以双螺环取代三聚磷腈基双苯甲酰氯和4-氨基(N-苯基)苯并噁嗪单体为原料合成了一种含双螺环取代三聚磷腈结构单元的苯并噁嗪树脂单体(HCP-5);采用傅立叶变换红外光谱仪(FT-IR)和核磁共振谱仪(1 H NMR,13 C NMR,31P NMR)表征了苯并噁嗪树脂单体的结构,基于FT-IR和示差扫描量热法研究了其固化行为,并利用热重分析和示差热重分析研究了HCP-5树脂单体、均聚物及其与双酚A型苯并噁嗪树脂(Bz)共聚物的热稳定性.结果表明,HCP-5均聚物具有很好的热稳定性和成炭性,其在317℃下的热失重为5%,在800℃下的残炭率为50%,可用于普通苯并噁嗪树脂改性.此外,HCP-5/Bz(1∶1;质量分数)共聚物在332℃下的热失重为5%,在800℃下的残炭率为48%.     

The Synthesis of Hexaphenylcyclotriphosphazene in Improved Yield

The reaction between phenylmagnesium bromide and hexachlorocyclotriphophazene (N ₃ P ₃ Cl ₆ ) ( 1 ) was reinvestigated for the synthesis of hexaphenylcyclotriphosphazene (N ₃ P ₃ Ph ₆ ) ( 2 ) in high yield. The reaction is complete within two weeks at room temperature using toluene as solvent. When the reactants (PhMgBr and N ₃ P ₃ Cl ₆ ) were employed in a 6:1, 36:1 and 72:1 molar ratio, compound 2 was obtained in 2.6%, 14%, and 33.4% yield, respectively. The formation of N ₃ P ₃ Cl ₆ ( 2 ) during the reaction was followed by thin-layer chromatography. Compound 2 was characterized by elemental analysis, IR, UV-VIS, ¹ H, ¹³ C, and ³¹ P NMR spectroscopy as well as by mass spectrometry.     

Synthesis and Characterization of a Novel Curing Agent for Epoxy Resin Based on Phosphazene Derivatives

In this work, a novel amine-terminated curing agent for epoxy resin based on hexachlorocyclotriphosphazene (HCCP) was synthesized through two steps of nucleophilic substitution reactions by phenol and 4-aminophenol. Its chemical structure was characterized by ¹H-NMR, Fourier transform infrared spectroscopy (FTIR) and mass spectrometry (MS). This curing agent was liquid at room temperature which made it easy to disperse in the epoxy resin. The rheological test showed the viscosity of the pre-polymer fluid decreased as the proportion of the curing agent increased so it improved the process performance. The curing reaction was studied by differential scanning calorimeter (DSC). The novel curing agent had a wider range of curing temperature and relatively lower curing temperature in comparison with the widely-using curing agent 4,4′-Diaminodiphenylmethane (DDM). The wider range of curing temperature helped lower the heat accumulation which was an important factor in curing process.