Syntheses and characterizations of two-component polyurethane flame retardant coatings using 2,4-dichloro modified polyesters

Polyurethane flame retardant coatings are composed of polyols and polyisocyanates. Flame retardant groups are usually introduced to the polyol structure. In this research intermediates were obtained by esterification of 2,4-dichlorobenzoic acid and trimethylolpropane for the purpose of introducing a flame retardant group to the polyol structure. Then chlorine-containing modified polyesters were synthesized by polycondensation of trimethylolpropane, adipic acid, 1,4-butanediol, and the intermediate. The content of 2,4-dichlorobenzoic acid in the intermediate was varied with 10, 20, and 30 wt%. Two-component polyurethane flame retardant coatings were prepared by blending the products with polyisocyanate. Various physical properties of these new flame retardant coatings were comparable to non-flame retardant coatings. They showed drying times of four to seven hours and pot life times of 14–20 hr, which could belong to the flame retardant coatings with long pot life time. The coating with 30 wt% 2,4-dichlorobenzoic acid showed a self-extinguishing property in the vertical burning test. Dept. of Chemical Engineering, Yongin 449-728, Korea. Ansan 425-110, Korea.     

Design and UV-curable behaviour of boron based reactive diluent for epoxy acrylate oligomer used for flame retardant wood coating

Difunctional boron-containing reactive flame retardant for UV-curable epoxy acrylate oligomer was synthesized from phenyl boronic acid and glycidyl methacrylate. The synthesized reactive diluent was utilized to formulate ultraviolet (UV)-curable wood coatings. The weight fractions of reactive diluent in coatings formulation was varied from 5 to 25 wt % with constant photoinitiator concentration. The molecular structure of reactive flame retardant was confirmed by Fourier-transform infrared, Nuclear magnetic resonance (NMR) and ¹¹B NMR spectral analysis. Further, the efficacy of flame retardant behaviour of coatings was evaluated using limiting oxygen index and UL-94 vertical burning test. Thermal stability of cured coatings films were estimated from thermogravimetric and differential scanning calorimetry analysis. The effects of varying concentration of reactive diluent on the viscosity of coatings formulation along with optical, mechanical and chemical resistance properties of coatings were also evaluated. The coatings gel content, water absorption behaviour, contact angle analysis and stain resistance were also studied.     

A novel phosphorus-containing poly(lactic acid) toward its flame retardation

An inherently flame-retardant poly(lactic acid) (PLA) was synthesized via the chain-extending reactions of dihydroxyl terminated pre-poly(lactic acid) (pre-PLA), which was synthesized by direct polycondensation of l-lactic acid using 1,4-butanediol as initiator and stannous chloride (SnCl₂) as catalyst, using ethyl phosphorodichloridate as chain extender. The resulting phosphorus-containing poly(lactic acid) (PPLA) was characterized by gel permeation chromatography (GPC), ¹H and ³¹P nuclear magnetic resonance (¹H, ³¹P NMR) and homonuclear correlation spectroscopy (COSY) and inductively coupled plasma-mass (ICP). A comprehensive flame retardant property of PPLA was evaluated by microscale combustion calorimetry (MCC), limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter test (CCT). PPLA has excellent flame retardancy and also can be used as a flame retardant for commercial PLA. Only 5 wt.% of PPLA added into PLA can obtain good flame retardant properties. As the content of PPLA is further increased to 10 wt.%, PLA can have much better flame retardancy (LOI = 35 and UL-94 V-0 rating), lower peak heat release rate (pHRR) and longer ignition time (TTI) than neat PLA. All those results mean that this novel approach to impart flame retardancy to PLA is very effective.     

Preparation and characterization of polyurethane flame‐retardant coatings using pyrophosphoric lactone‐modified polyesters/isophorone diisocyanate–isocyanurate

Pyrophosphoric lactone‐modified polyester containing two phosphorous functional groups in one structural unit of base resin was synthesized to prepare a nontoxic, reactive flame‐retardant coatings. Then, the pyrophosphoric lactone‐modified polyester was cured at room temperature with isocyanate and isophorone diisocyanate (IPDI)–isocyanurate to get a two‐component polyurethane flame‐retardant coatings (TAPPU). Comparing the physical properties of the films of TAPPU with the film of nonflame‐retardant coatings, no deterioration of physical properties was observed with the incorporation of a flame‐retarding component into the resin. Three kinds of flame retarding tests were conducted, including the 45° Meckel burner method, limiting oxygen index method (LOI method), and oxygen combustion method with Cone calorimeter. It was observed that the char lengths were 3.1～4.5 cm and LOI values were 27～30%. These results indicate that the prepared coatings are good flame‐retardant ones. It was also found that the flame retardancy of those coatings was increased with the contents of phosphorous. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2316–2327, 2001     

新型磷氮溴复合阻燃剂的制备及其阻燃聚丙烯的研究

以氢溴酸三聚氰胺盐（MHB）、聚磷酸铵（APP）、阻燃增效协同剂2、3-二甲基-2、3-二苯基丁烷( DMDPB )3种物质为原料复配成一种新型磷溴氮复合阻燃剂,将不同复配比例的复合阻燃剂添加到聚丙烯（PP）中,对阻燃PP材料的阻燃性能、力学性能及熔体流动速率进行测试,探讨3种物质的最佳复配比;并研究了该复合阻燃剂的添加量对材料阻燃性能的影响。结果表明,当MHB：APP：DMDPB的配比为10:10:1时,为最佳复配比;当磷氮溴复合阻燃剂的添加量为2.0 %（质量分数,下同）时,其极限氧指数值为30.8 %,燃烧等级为UL 94 V-1。     

Flame retardancy of hollow glass microsphere/rigid polyurethane foams in the presence of expandable graphite

Rigid polyurethane foams (RPUF) filled with various loadings of expandable graphite (EG) or/and hollow glass microspheres (HGM) were prepared by cast molding. The flame retardant properties of these composites were investigated by limiting oxygen index (LOI), horizontal and vertical burning tests. The composite with 10 wt % HGM and 20 wt % EG had the best flame retardant properties, and its LOI value reached 30 vol %. The addition of an appropriate loading of HGM improved the compressive strength and modulus of RPUF and EG/RPUF. When the HGM content arrived at 10 wt %, the compressive strength and modulus of the composites reached the maximum value. The dynamical mechanical analysis (DMA) showed that the addition of EG and HGM made the glass transition temperature shift to a higher temperature, and 10 wt % EG and 10 wt % HGM filled RPUF had the highest storage modulus. The scanning electronic microscope (SEM) observation indicates that the additives led to the decrease in the cell size. In addition, the flame retardant mechanism, the thermal properties, the burned surfaces and the interface surfaces were elucidated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preparation and physical properties of polyurethane flame retardant coatings using phosphorus-containing lactone modified polyesters

Two-component polyurethane flame retardant coatings were prepared using phosphorus-containing lactone modified polyesters (PLMPs) and polyisocyanate. PLMPs were synthesized by poly-condensation of dimethyl phenylphosphonate, a flame retardant component with polycaprolactone, adipic acid, and trimethylolpropane. PLMPs were prepared with dimethyl phenylphosphonate content from 10 to 20 wt%. It was found that various physical properties of these new flame retardant coatings were comparable to non-flame retardant coatings. The flammability of coatings depends strongly on the dimethyl phenylphosphonate content in PLMP. Coatings with 20 wt% dimethyl phenylphosphonate content did not burn in the vertical burning test. Dept. of Chem. Eng., Yongin 449-728, Korea. Ansan 425-110, Korea.     

Thermal stability,flame retardance,and mechanical properties of polyamide 66 modified by a nitrogen–phosphorous reacting flame retardant

Flame‐retardant polyamide 66 (PA66) was prepared by the polymerization between PA66 prepolymer and N‐benzoic acid (ethyl‐N‐benzoic acid formamide) phosphamide (NENP). Compared with the pure PA66, the flame‐retardant PA66 exhibited better thermal stability, as indicated by thermogravimetric analysis results. The limiting oxygen index was 28% and the UL‐94 test results of the flame‐retardant PA66 indicated a V‐0 rating when the content of the NENP prepolymer was 5 wt %. The flammability and flame‐retardant mechanism of PA66 were also studied with cone calorimetry and scanning electron microscopy/energy‐dispersive X‐ray spectroscopy, respectively. The mechanical properties results show that the flame‐retardant PA66 resin had favorable mechanical properties. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43538.     

Flame‐retardant fabric systems based on electrospun polyamide/boric acid nanocomposite fibers

To examine the feasibility of developing flame‐retardant‐textile coated fabric systems with electrospun polyamide/boric acid nanocomposites, fiber webs coated on cotton substrates were developed to impart‐fire retardant properties. The morphology of the polyamide/boric acid nanocomposite fibers was examined with scanning electron microscopy. The flame‐retardant properties of coated fabric systems with different nanoparticle contents were assessed. The flame retardancy of the boric acid coated fabric systems was evaluated quantitatively with a flammability test apparatus fabricated on the basis of Consumer Product Safety Commission 16 Code of Federal Regulations part 1610 standard and also by thermogravimetric analysis. The 0.05 wt % boric acid nanocomposite fiber web coated on pure cotton fabric exhibited an increment in flame‐spreading time of greater than 80%, and this indicated excellent fire protection. Also, the coated fabric systems with 0.05% boric acid nanocomposite fiber webs exhibited a distinct shift in the peak value in the thermal degradation profile and a 75% increase in char formation in the thermooxidative degradation profile, as indicated by the results of thermogravimetric analysis. The results show the feasibility of successfully imparting flame‐retardant properties to cotton fabrics through the electrospinning of the polymer material with boric acid nanoparticles. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

茶皂素基膨胀型阻燃剂的制备及其在涂料中的应用

采用多羟基、多羧基的活性天然产物茶皂素为原料,与聚磷酸铵和季戊四醇在一定条件下反应,制备一种聚磷酸酯类茶皂素基三位一体新型环保膨胀型阻燃剂。采用傅里叶红外分析技术对阻燃剂进行了结构表征,采用综合热分析仪对阻燃剂的热降解性能进行了研究。结果表明,茶皂素与聚磷酸铵、季戊四醇发生反应,生成聚磷酸酯类茶皂素基膨胀型阻燃剂,且该阻燃剂具有良好的热稳定性,降解热释放较小,高温残留率高,最终的质量残留率高达30.77%。将制备阻燃剂用于阻燃涂料中,并采用氧指数测试仪和锥形量热仪研究了阻燃涂料的阻燃性能和热解性能。研究表明,茶皂素基三位一体膨胀型阻燃剂能显著提高涂料的阻燃性能,阻燃涂料的氧指数值高达34.2%,耐火时间为11.1 min,且锥形量热实验中,该阻燃涂料试样的平均热释放速率（m-HRR）为36.18 kW/m2,总热释放量（THR）为5.25 kJ/m2,平均有效燃烧热（m-EHC）为5.11 kJ/kg,与含复合型阻燃剂的阻燃涂料试样相比,阻燃性能得到极大提高。该制备阻燃剂不含卤素,集三源一体,具有阻燃性能优越,相容性能良好,高效环保等优点。     

Influence of expandable graphite on flame retardancy and thermal stability property of unsaturated polyester resins/organic magnesium hydroxide composites

An eco-friendly flame retardant unsaturated polyester resin (UPR) material was prepared by combination organic magnesium hydroxide (OMH) and expandable graphite (EG). Different from direct addition of magnesium hydroxide (MH) in UPR matrix-like traditional method, OMH as a reactive monomer participates in the polycondensation reaction of UPR was more effective in improving the compatibility of flame retardant with matrix. Interestingly, the flame retardant UPR composites exhibited a more satisfactory flame retardant effect when a certain amount of 8 wt % EG was added into UPR/OMH matrix because of the synergistic effect between OMH and EG, resulted in the limited oxygen index from 21.7 to 28.5% and UL-94 test passed V-0 rating. Moreover, the peak heat release rate, total heat release, and smoke production rate of flame retardant UPR composites significantly reduced. The excellent flame retardancy was due to the formation of a dense and continuous carbon layer in the later stages of combustion. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 47881.     

Synthesis and characterization of new flame‐retardant poly(amide‐imide)s containing phosphine oxide and hydantoin moieties in the main chain

Six new flame‐retardant poly(amide‐imide)s (PAIs) 9a–f with high inherent viscosities containing phosphine oxide and hydantoin moieties in main chain were synthesized from the polycondensation reaction of N,N′‐(3,3′‐diphenylphenylphosphine oxide) bistrimellitimide diacid chloride 7 with six hydantoin derivatives 8a–f by two different methods such as solution and microwave assisted polycondensation. Results showed that the microwave assisted polycondensation, by using a domestic microwave oven, proceeded rapidly, compared with solution polycondensation, and was completed in about 7–9 min. All of the obtained polymers were fully characterized by means of elemental analysis, viscosity measurements, solubility test, and FTIR spectroscopy. Thermal properties and flame retardant behavior of the PAIs 9a–f were investigated using thermal gravimetric analysis (TGA and DTG) and limited Oxygen index (LOI). Data obtained by thermal analysis (TGA and DTG) revealed that these polymers showed good thermal stability. Furthermore, high char yields in TGA and good LOI values indicated that these polymers are capable of exhibiting good flame retardant properties. These polymers can be potentially utilized in flame retardant thermoplastic materials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5062–5071, 2006     

叶蜡石改性膨胀型涂料阻燃性能研究

为了提高木质胶合板的阻燃性能,以聚磷酸铵(APP)-季戊四醇(PER)-尿素为基础配方,叶蜡石粉作为改性添加剂制备膨胀型阻燃涂料(IFRC);采用锥形量热仪、静态接触角测量仪、扫描电镜、X射线衍射仪和拉力机等仪器对试样的阻燃性能、疏水性能和力学性能进行了表征,并且研究了叶蜡石粉含量对所制备涂料性能的影响。结果表明:在膨胀型阻燃涂料中加入适量的叶蜡石可以提高涂料的阻燃效果,当掺加叶蜡石粉的质量分数为2%时,涂料的火灾增长指数(FGI)降低了47%,火灾性能指数(FPI)增加了89%,并且阻燃性能指数(FRI)提高至2.5倍;叶蜡石粉的加入促进涂层在燃烧过程中形成连续致密的炭层结构,并形成了可以有效隔绝氧气和热量的熔融态物质,进一步增强了涂料的阻燃隔热性能;此时涂层的疏水性能和燃烧后木质胶合板的力学性能达到最佳,水接触角增大了8°,拉伸强度提高了45%,断裂伸长率也提高至8.5倍。本文研究结果对木质胶合板阻燃体系涂料配方的开发有一定的参考作用。     

Investigation of flame retardancy and physical–mechanical properties of zinc borate/boric acid polyester composites

The glass fiber reinforced polyester composite materials were prepared with varying contents of boric acid, zinc borate, and magnesium hydroxide as flame retardants to improve the flame retardancy of the composites. Experimental results showed that boric acid exhibited a good flame retardant effect on the polyester composite. When boric acid content is used as 15 wt %, the Limiting Oxygen Index (LOI) value of the composite reached upto 25.3. The increase in boric acid content from 15 to 30 wt %, the LOI values of composite were enhanced from 25.3 to 34.5 by 9.2 units. The LOI values of the composite samples increased with increasing boric acid content. The smoke density results showed that the addition of glass fiber and flame retardants decreased the smoke density of the unreinforced polyester resin. The mechanical properties of the composites have decreased by the addition of flame retardants. The scanning electron micrographs taken from fracture surfaces were examined. The flame retardants, such as boric acid, were well dispersed in the glass fiber reinforced polyester composites and obviously improved the interfacial interaction between glass fibers and polyester composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

DPDBO/Sb2O3/DMDPB在LDPE阻燃处理中的应用

研究了2,3-二甲基-2,3-苯基丁烷(DMDPB)、三氧化二锑(Sb2O3)和十溴二苯醚(DBDPO)的加入对低密度聚乙烯(LDPE)的拉伸和阻燃性能的影响探讨了DBDPO与Sb2O3加入量的不同给LDPE的拉伸强度、断裂伸长率和阻燃性能带来的差异。同时研究表明少量的DMDPB加入LDPE／Sb2O3／DBDPO体系,即可显著提高断裂伸长率和阻燃性能。     

阻燃剂赛克三硅酸二溴丙酯的合成及应用研究

以三（2-羟乙基）异氰尿酸酯（赛克）、四氯化硅与2,3-二溴丙醇为原料,合成阻燃剂赛克三硅酸二溴丙酯。探讨了溶剂、反应温度与物质的量之比对产物收率的影响,优化的工艺条件：四氯化硅、2,3-二溴丙醇、赛克与2,3-二溴丙醇的量之比为3∶3∶1∶6.7。四氯化硅先与2,3-二溴丙醇在45℃反应2 h,再加入赛克于90℃反应11 h,最后滴入2,3-二溴丙醇保温90℃反应8 h;产物收率为93.3%。通过FTIR、^1H NMR、差热分析及极限氧指数等表征产物的结构及性能;应用实验表明该产物阻燃效能高,适合作聚氯乙烯（PVC）等材料的阻燃剂。在较佳用量下PVC材料的极限氧指数为25%,具有良好的阻燃性、成炭防滴落性能。     

氮–磷协效阻燃聚酰胺66制备与性能

为改善聚酰胺66(PA66)的阻燃性能,以氮系阻燃剂三聚氰胺氰尿酸盐(MCA)和磷系阻燃剂9,10–二氢–9–氧杂–10–磷酰杂菲–丁二酸(DDP)协效,将原位聚合法与共聚法结合,经熔融缩聚制备氮-磷协效阻燃PA66树脂。利用傅立叶变换红外光谱仪、差示扫描量热仪、万能材料试验机、垂直燃烧仪和极限氧指数仪等研究阻燃PA66树脂的结构与性能。结果表明:随DDP含量的增加,阻燃PA66的相对黏度、熔点、结晶度和力学性能均呈下降趋势。当MCA含量为2%,DDP含量为4%时,阻燃PA66(FRPA66–4)的熔点、结晶温度和结晶度分别降至250.78℃,203.74℃,29.21%,FRPA66–4的拉伸强度和断裂伸长率分别下降为68.8 MPa和69.5%,比PA66降低了17.01%和17.46%。但PA66的阻燃性能得到改善,FRPA66–4的垂直燃烧测试达UL94 V–0级,极限氧指数为30.6%,阻燃效果良好。     

Synthesis and properties of novel flame‐retardant poly(amide‐imide)s containing phosphine oxide moieties in main chain by microwave irradiation

Eight new flame‐retardant poly(amide‐imide)s with high inherent viscosities containing phosphine oxide moieties in main chain were synthesized from the polycondensation reaction of N,N′‐(3,3′‐diphenylphenylphosphine oxide) bistrimellitimide diacid chloride 7, with eight ;aromatic diamine 8a–h by two different methods such as solution and microwave‐assisted polycondensation. Results showed that the microwave‐assisted polycondensation by using a domestic microwave oven proceeded rapidly, compared with solution polycondensation and were completed within about 10–12 min. The resulting poly(amide‐imide)s 9a–h showed high thermal stability and flame‐retardant properties. All of the obtained polymers were fully characterized by means of elemental analysis, viscosity measurements, solubility test, and FTIR spectroscopy. Thermal properties of the PAIs 9a–h were investigated by using thermal gravimetric analysis (TGA), derivative thermogravimetric analysis (DTG), and differential scanning calorimetry (DSC). Char yield measurements at 600°C demonstrated that incorporating phosphine oxide moieties in polymer backbone markedly improves their flame retardancy. All of the earlier polymers were soluble at room temperature in various organic solvents such as NMP, DMF, DMSO, DMAc, and concentrated sulfuric acid. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 4263–4269, 2006     

涂料用本体阻燃树脂单体研究进展

本体阻燃树脂是让阻燃单体参与聚合反应,使之成为合成树脂的结构单元而赋予其较好的阻燃性能。该方法具有阻燃剂使用量少,所得树脂阻燃性能持久,基本不影响材料其他性能等优点。文章综述了近年来国内外研究人员对4类含有不同元素的涂料用本体阻燃树脂单体的研究进展,重点介绍了各类阻燃单体的合成方法,在不同合成树脂中的应用,以及所得树脂的成炭率、极限氧指数、UL-94测试等燃烧性能。最后,对涂料用本体阻燃树脂单体的发展前景作了展望。     

三嗪膨胀阻燃剂/硅酸镁协效阻燃TPU的制备及性能研究

以三嗪成炭发泡剂（CFA）及聚磷酸铵（APP）复配成膨胀阻燃剂(IFR),以硅酸镁(MgSiO3)为协效剂添加到热塑性聚氨酯弹性体(TPU)中制备阻燃TPU材料,研究了阻燃TPU材料的阻燃性能、力学性能、热降解行为和炭层的表面形貌。结果表明,纯TPU材料的极限氧指数仅为22.0 %,在空气中极易燃烧,当IFR添加量为28 %（质量分数,下同）,MgSiO3添加量5 %时,材料的极限氧指数提高到37.1 %,通过UL 94 V-0级,表现出很好的阻燃效果;但是IFR/MgSiO3的加入使材料的拉伸强度和断裂伸长率明显下降,也使得TPU材料的起始热分解温度提前,最大热降解速率峰值降低,同时材料的残炭量得到了很大程度的提高。