Flame retardant epoxy resins from bisphenol-A epoxy cured with hyperbranched polyphosphate ester

A novel hyperbranched polyphosphate ester (HPE) was synthesized via the polycondensation of bisphenol-A and phosphoryl trichloride. The formed HPE was characterized by FTIR, ¹H NMR and ³¹P NMR to confirm its structure. Then, a series flame retardant epoxy resins from bisphenol-A epoxy cured with HPE and bisphenol-A were prepared. The combustion behavior of the flame retardant epoxy resins was studied using limiting oxygen index (LOI) and cone calorimeter test. The LOI value increased from 23 to 32 when HPE, instead of bisphenol-A, was used as a curing agent. The cone calorimeter test data revealed that the cured bisphenol-A epoxy resin with HPE as a curing agent possessed improved flame retardancy. The photo graphs and scanning electron microscopy (SEM) of char residues confirmed the cone calorimeter results.     

新型潜伏性固化剂的合成及性能

利用9,10-二氢-9-氧杂-10-磷杂菲-10-氧化物（DOPO）的亲核特点,将其与双氰胺进行加成反应,合成了一种潜伏性固化剂,并将其与环氧树脂进行固化反应。用FTIR、¹H NMR分析了固化剂的结构;用DSC、TG分析了固化剂和固化体系的热性能。结果表明,与双氰胺相比,固化剂的熔点降低了近100℃,固化温度下降近 40℃;优化了固化工艺参数;考察了体系的潜伏性和难燃特性,其储存期超过100 d,LOI达到22。     

Synthesis and properties of semi-crystalline hyperbranched poly(ester-amide) grafted with long alkyl chains used for UV-curable powder coatings

A series of semi-crystalline hyperbranched poly(ester-amide)s by modifying hydroxyl end groups of hyperbranched poly(ester-amide) (HP) with IPDI-C18 and IPDI-HEA in different ratios were synthesized and characterized by FTIR, NMR and GPC. Their crystallization behaviors and thermal properties determined by X-ray diffraction (XRD) and differential scanning calorimetry (DSC) showed that the high substitution degree of hydroxyl groups of hyperbranched poly(ester-amide) (HP) with IPDI-C18 resulted in higher degree of crystallization and thus glass transition temperature (T_g) up to 43 °C. The photopolymerization kinetics investigated by photo-DSC showed that the obtained semi-crystalline hyperbranched resins have high photopolymerization rate and final unsaturation conversion, which is very promising for UV-curable powder coating applications.     

有机硅改性水性环氧固化剂的合成及表征

A novel waterborne epoxy curing agent was prepared using 3-glycidoxypropyl trimethoxysilane （GPTMS） as a termination agent of adduct, which was synthesized by triethylene tetramine （TETA） and liquid epoxy resin （E-51）. The effects of the reaction temperature and time on the synthesis process were investigated experimentally. The particle size and the distribution of water dispersion of the curing agent were measured by dynamic light scattering（DLS）. The structure of the products was characterized by Fourier transform infrared spec-trometer （FTIR） and ^1H-nuclear magnetic resonance （^1H NMR）. The properties of the synthesized curing agent and the epoxy resin film cured by it were also measured. The results showed that the appropriate temperature for the synthesis of adduct was at 65-75℃ and the reaction time was 4-5h, and that the suitable reaction temperature of curing agent synthesis was 75-85℃ and the reaction time was 3-4h. When the mass ratios of GPTMS and acetic acid were 3%-5% and 5%-10% respectively, the hardness, water resistance and adhesion of the cured film were improved significantly.     

降冰片烯酰亚胺型双苯并嗪的合成及性能

首先用降冰片烯二酸酐、对氨基苯酚为原料合成降冰片烯酰亚胺（NI）,然后用合成的NI、4,4-二氨基二苯醚（ODA）和多聚甲醛为原料进行Mannich反应合成出降冰片烯酰亚胺型双苯并嗪（NI-BOZ）,经高温固化后形成热固性树脂。用FTIR、¹H NMR、¹³C NMR分析了NI和NI-BOZ的化学结构,证实了所得的目标产物;用DSC对NI-BOZ的固化动力学进行研究;用DMA和TGA分析了NI-BOZ的固化物的热性能。结果表明：NI-BOZ的固化反应活化能为86.27 kJ·mol^-1,反应级数为0.91;poly（NI-BOZ）树脂空气条件下的玻璃化转变温度为215℃,氮气条件下失重5%的温度为445℃,失重10%的温度为467℃,在800℃的残碳率为63%。     

含双DOPO的双酚A-单苯并(口恶)嗪合成、表征及其与环氧树脂共聚物的阻燃性能

以含双DOPO-双酚A、苯胺和多聚甲醛为原料,合成了含双DOPO的双酚A-单苯并(口恶)嗪(1DD)。采用红外、核磁(氢谱核磁和碳谱核磁)等分析手段对1DD的化学结构进行了表征;采用DSC对1DD的固化特性进行研究,使用TG分析了所得聚苯并(口恶)嗪的热稳定性。再将1DD与环氧树脂以0.5/1的质量比进行共混,按照一定的程序进行升温固化,得到共聚物P1DD-ER。采用UL94垂直燃烧实验、极限氧指数仪(LOI)测试了共聚物的阻燃性能。结果表明:含双DOPO的双酚A-单苯并(口恶)嗪树脂的起始熔点约为185℃,在222℃处有一个很明显的放热峰。固化后的树脂从348℃开始分解,在463℃分解速率达到最快,在800℃时的残碳率为35.78%。制备的苯并(口恶)嗪可以用作环氧树脂的固化剂,且其共聚物具有很好的阻燃性能,LOI可以达到37,UL94等级为V-0。     

阻燃抑烟环氧树脂的合成及其性质

以磷酸、三聚氰胺、尿素为原料制备阻燃抑烟剂聚磷酰氰胺脲,然后将其应用于TDE-85#环氧树脂中,以顺丁烯二酸酐为固化剂制备了阻燃抑烟环氧树脂。研究了阻燃抑烟剂聚磷酰氰胺脲的吸湿性,纯环氧树脂和阻燃抑烟环氧树脂的极限氧指数、UL-94阻燃性、隔热性能、烧蚀速率和透光率等。研究结果表明,聚磷酰氰胺脲对环氧树脂具有非常优异的阻燃、抑烟功效。     

聚双胍/环氧树脂体系潜伏性固化过程

用己二胺与双氰胺熔融缩聚, 合成了一种新型潜伏性环氧树脂固化剂, 并研究了其与环氧树脂的固化过程。用FTIR、XPS、¹H NMR分析了固化剂的结构;用DSC分析得到了固化剂与环氧树脂的适宜配比、固化体系的适宜固化温度及固化动力学参数;通过XRD分析了固化物的相结构;通过TG分析了固化物的热稳定性。结果表明, 与双氰胺环氧树脂固化体系相比, 固化温度降低近70℃, 同时潜伏性能良好, 30 d内固化度少于10%, 热稳定性能良好, 热分解温度超过300℃。     

基于官能化笼型倍半硅氧烷改性环氧涂层的研究

以γ-缩水甘油基环氧丙氧基三甲氧基硅烷为原料,乙醇和甲醇作为混合溶剂,在酸性条件下进行水解缩聚反应合成了环氧基POSS(EP-POSS),并应用于环氧树脂的改性。利用红外光谱(FT-IR)、核磁共振谱( ¹H NMR及 ²⁹Si NMR)对EP-POSS的结构进行表征;利用热重(TGA)、扫描电镜(SEM)对改性环氧涂层耐热性及断面形貌进行测试、观察,并分别讨论了促进剂与EP-POSS的加入量对环氧树脂力学性能的影响。结果表明:EP-POSS的引入,降低了固化温度,提高了热稳定性,增强了涂层的韧性,且当促进剂与EP-POSS添加量分别为0.5%、3%时,涂层的综合性能显著提高。     

改性聚乙烯醇缩丁醛胶粘剂的研制

以聚乙烯醇缩丁醛(PVB)为主料，乙醇和乙酸乙酯为溶剂，酚醛树脂为改性树脂，环氧树脂为增粘树脂，自制多元胺类固化剂，采用共混改性法，配制出无色透明、对环境友好、常温、接触压力固化的双组分胶粘剂。对于PVB的结构、PVB与改性树脂的配比、以及溶剂的选择对胶粘剂性能的影响进行了研究。     

Molecular design and properties of intrinsic flame-retardant P-N synergistic epoxy resin

In recent years, the poor weather resistance and aging resistance of additive flame retardants have caused researchers to pay attention to reactive flame retardants. A novel P-N coacting epoxy curing agent with intrinsic flame retardancy was designed and synthesized. The mechanical properties, crosslinking curing properties and flame-retardant properties of intrinsic flame-retardant epoxy resin were characterized. The results show that the cross-linking curing performance of hexa (3,5-diamino-1,2,4 triazolyl)-cyclotriphosphonitrile) (VCP) is lower than that of DDM. This is due to the decrease in cross-linking density caused by the VCP ring molecular structure. Therefore, the mechanical properties of the epoxy resin cured with VCP decreased, but the flame-retardant properties of the material significantly improved. The limiting oxygen index of the VCP/EP flame retardant epoxy thermosets was 27.3%, reaching the UL 94 V-1 level. The peak heat release rate and total heat release rate of the VCP/EP flame retardant epoxy thermosets were significantly reduced. The flame retardancy mechanism was studied by Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, and x-ray photoelectron spectroscopy. The results show that the intrinsic flame-retardant P-N coacting epoxy resin has excellent curing and flame-retardant properties.     

两亲性超支化聚酯-酰胺的制备及其性能

引言 在同一分子中,既含有亲水性链段,又含有疏水性链段的聚合物称为两亲性聚合物,这种聚合物的凝聚态常具有多相结构,并对不同极性的化合物都具有一定的亲和力,这种独特的性质就使其既不同于低分子表面活性剂也异于一般的离子聚合物.带有亲水性支链的两亲性聚合物具有很大的应用潜能.可以用作乳液和分散体的稳定剂,颜料及塑料的表面改性剂,高分子材料的助剂及改性剂等[1-2].     

Synthesis and properties of a phosphate ester as curing agent in an epoxy resin system

Phosphate ester compounds display good flame retardancy effect in epoxy resin systems. In this paper, several novel phosphate esters, used as curing agents for epoxy resins, were synthesized based on P₂O₅, phosphoric acid, and different types of alcohol. The structures of phosphate esters were characterized by ³¹P nuclear magnetic resonance (³¹P NMR). Then, a series of flame retardant epoxy composites were prepared by curing the epoxy resins (E-44) with the phosphate esters. The flame retardancy and thermal degradation behaviors of flame retardant epoxy composites were investigated by cone calorimeter test (CCT) and thermogravimetric analysis (TGA), respectively. The results of CCT indicated that phosphate esters can significantly decrease heat release rate, total heat release (THR), and smoke production rate. The sample cured by butyl phosphate ester from phosphorus pentoxide, phosphoric acid and butanol showed the best flame retardant performance among all samples. The TGA results showed that phosphate esters could enhance char residues of flame retardant epoxy composites when compared with those of a composite using T31 as a curing agent at high temperature. It may be concluded that good flame retardant properties of flame retardant epoxy composites are related to the formation of a protective phosphorus-rich char layer. These phosphate esters have a good future on flame retardant epoxy composites.     

Newly developed urethane modified polyetheramide-based anticorrosive coatings from a sustainable resource

Polyetheramide resin was prepared from N,N-bis (2-hydroxy ethyl) soybean oil fattyamide (HESA) and bisphenol-A. It was further treated with toluylene-2,4-diisocyanate (TDI) in different weight percent to obtain urethane modified polyetheramide resins (UPEtA). The structural elucidation of UPEtA was carried out by FT-IR, ¹H NMR and ¹³C NMR spectroscopic techniques. Physico-chemical and physico-mechanical analyses were performed by standard methods. The solubility of UPEtA was determined in various organic solvents at room temperature. TGA and DSC techniques were used to analyze the thermal and curing behavior of the UPEtA resin. The coatings of urethane modified polyetheramide were prepared on mild steel strips. The anticorrosive behavior of UPEtA resin-based coatings in acid, alkali, water and xylene were investigated. The studies reveal that the newly developed UPEtA resin can be used as an anticorrosive coatings material.     

2,4,6-三溴苯胺对环氧固化物阻燃耐热性的影响

用氧指数(LOI)、TG法研究了2,4,6 三溴苯胺(TBA)对环氧树脂酸酐固化物阻燃耐热性的影响,结果表明TBA有较好的阻燃效果,其与Sb2O3和磷酸三苯酯(TPP)配用时具有协同阻燃效应,且对环氧树脂酸酐固化物的热稳定性影响较小。     

Preparation and characterization of crosslinked polyimide–poly(dimethylsiloxane)s

Crosslinked polyimide–poly(dimethylsiloxane)s with theoretical content of the siloxane phase up to 60 wt% were prepared. The starting materials were p-aminophenyltrimethoxysilane terminated polyamic acids with number average molecular weight of 10,000 g mol⁻¹, based on 4,4′-oxydiphthalic anhydride and 4,4′-oxydianiline and dimethoxydimethylsilane. The structure of the prepared polymeric materials was analyzed using ²⁹Si and ¹³C NMR solid-state spectroscopy. Their thermal and mechanical properties, chemical resistance and density were evaluated. The influence of the basic catalysts employed (ammonium hydroxide) on the course of the reaction and properties of the materials was also studied.     

液体乙烯基硅树脂的制备及固化反应动力学

合成了一种液体乙烯基硅树脂,并用FT-IR、GPC、¹H NMR和²⁹Si NMR等手段对其结构进行表征。采用非等温差示扫描量热法（DSC）研究了乙烯基硅树脂/苯基含氢硅油体系的固化反应动力学,用Kissinger方程和高级等转化率法（Vyazovkin方法）分别计算了该体系的表观活化能E_a,用Málek法进行模型拟合动力学分析,通过T-β外推法确定该体系的固化工艺参数。结果表明：Kissinger法和Vyazovkin法得到的活化能分别为85.3 kJ·mol^-1和84.0 kJ·mol^-1,二者所得结果的差别较小;乙烯基硅树脂体系固化动力学符合Šesták-Berggren（m,n）模型,m和n分别为0.092、1.440,拟合曲线与实验的DSC曲线吻合;该树脂体系的近似凝胶化温度为89.1℃,固化温度为127.8℃,后处理温度157.6℃。     

Synthesis of fluorine-containing polyphosphates: low-temperature solution polycondensation of bisphenol AF and aryl phosphorodichloridates

This paper describes the synthesis of aromatic polyphosphates from the reaction of various aryl phosphorodichloridates with bisphenol AF in a chlorinated hydrocarbon solvent under low-temperature conditions. The polyphosphates obtained were characterized by IR,¹³3C- and ³¹P-NMR spectra, elemental analysis, inherent viscosity, TGA, DSC, X-ray diffraction, LOI, contact angle and molar mass measurement. All the polyphosphates obtained had high yields and the inherent viscosities were in the range 0.25–0.31 dl g⁻¹. The weight average molar masses ( ) were in the range 0.96 × 10⁴−1.33 × 10⁴ with relatively narrow molar mass distributions ( ). All the polymers, except polymer C, are stable up to 250°C, exhibited 10% loss of mass at 417–463°C, and had 20–30% residual mass at 700°C in nitrogen. The X-ray diffraction patterns revealed that all the polyphosphates are semicrystalline and polymer E, containing a flexible ether linkage, has a relatively large degree of crystallinity. The fluorine-containing polyphosphates have glass-transition temperatures between 81–108°C and polymer C, having a NO₂ group in the side chain phenyl ring, has the highest T_g value. The polyphosphates obtained from bisphenol AF showed better thermal stabilities and higher LOI values than those obtained from bisphenol A. The polyphosphates have good flame retardancy, as indicated by high limiting oxygen index values in the range of 47–60. The water contact angles (θ_w) of all polyphosphates are in the range of 76–109°. The contact angles of polymers A and B are larger than other polyphosphates which contain more oxygen content or bromine atoms (polymers C, D and E).     

Development of structural characterization and physicochemical behaviour of triphenylamine blocks

A novel multitriphenylamine substituted derivatives, possessing the respective photochromic groups were synthesized by Stille cross-coupling methodology. The hyperbranched structures have been characterized by ¹H NMR, ¹³C NMR. Obtained structures show good stability in common organic solvents such as CHCl₃, toluene and CH₂Cl₂ and exhibit excellent thermal stability. Electrochemical results and theoretical calculation suggest that oxidation and reduction start from the side of amine and branching five member heterocycle ring moieties, respectively.     

Flame retardant epoxy resin for electrical and electronic applications

Amine‐cured epoxy resins were prepared at 2% by weight phosphorus content using four halogen‐free flame retardants; poly(m‐phenylene methyl phosphonate) (Fyrol PMP); 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide; red phosphorus; and aluminum diethylphosphinate (OP1230). The effect of these additives on the properties of cured epoxy, including glass transition temperature, thermal stability, and fire retardancy (cone calorimetry), were studied and were compared with the conventionally used flame retardant, tetrabromobisphenol‐A (TBBA). All properties are improved for the non‐halogenated materials compared with TBBA. Further, the stoichiometric amounts of Fyrol PMP and TBBA (without an external curing agent) were reacted with epoxy to determine if they could be used as a flame retardant and as a curing agent; Fyrol PMP effectively acts as a flame retardant and as a curing agent. Evolved gas analysis is also discussed through thermogravimetric analysis/Fourier transform infrared spectroscopy. Copyright © 2013 John Wiley & Sons, Ltd.