Study on the preparation and properties of novel transparent fire-resistive coatings

A cyclic polyphosphate (CPPA) was synthesized by the reaction of polyphosphoric acid and pentaerythritol. Polyethylene glycol (PEG) was introduced in the structure of CPPA to improve its solubility in water and ethanol and five kinds of reactive type flame retardants (MCPPA) were obtained. ³¹P NMR, ¹H NMR, FTIR, and TGA were used to characterize the composition and structure of CPPA and MCPPAs. The experimental results showed that there were 25% cyclic P–O–C structures in the product and MCPPA had better carbonization ability than CPPA. Five kinds of transparent fire-resistive coatings were prepared by the mixing of amino resin with five kinds of MCPPAs. The results of the fire protection test showed that both the fire-resistive time of coatings and intumescent factor of char layers decreased with the increase of molecular weight of PEG. The results of TGA and EDS showed that the carbonaceous residue of coatings and the antioxidation ability of char layers also decreased regularly with the increase of molecular weight of PEG. The SEM images demonstrated that the coating prepared with low molecular weight of PEG contributed to dense form structure and narrow distribution of cell size. Above all, the transparent fire-resistive coating prepared with PEG 200 had the best fire retardancy and stable thermal behavior.     

ZnO对PP/MPP/PEPA膨胀阻燃体系的协同作用

以ZnO为阻燃协效剂,采用多聚磷酸蜜胺(MPP)和笼状季戊四醇磷酸酯(PEPA)复配阻燃剂,制备了具有良好阻燃性能的无卤阻燃PP。研究了ZnO用量对PP阻燃性能和协效作用的影响。结果表明:添加少量的ZnO即可显著提高PP的阻燃性能。当MPP、PEPA和ZnO添加量分别为12%、8%和1%时,阻燃PP的氧指数高达29.5%。TGA、FTIR分析和体式显微镜观测结果表明:添加ZnO可以催化MPP/PEPA间的酯化反应,促进体系成炭,形成更致密的炭层,从而提高材料的阻燃性能。     

含PEPA基团苯并噁嗪的合成与性能

以水杨醛、对氨基苯酚和PEPA的衍生物为原料,合成了含笼型膦酸酯结构的苯并噁嗪单体(PEPA-Bz),用FTIR和1HNMR对其结构进行了表征。PEPA-Bz均聚物热失重分析(TGA)结果表明,该聚苯并噁嗪具有较好的热稳定性和成炭性能,起始热分解温度235℃,700℃时残炭率为53%,氧指数达到38.7。采用FTIR和TGA分别考察了PEPA-Bz与双酚A型苯并口恶嗪树脂(Ba)的开环共聚行为及共聚物的热性能。结果表明,含PEPA-Bz苯并噁嗪共聚物的阻燃性和成炭性明显优于不含PEPA-Bz的双酚A型苯并噁嗪树脂。     

Role of caged bicyclic pentaerythritol phosphate alcohol in flame retardancy of PA6 and mechanism study

A series of PA6/PEPA composites were prepared by mixing caged bicyclic pentaerythritol phosphate alcohol (PEPA) and polyamide 6 (PA6) at different feed ratios by the melt‐blending method in a twin‐screw extruder. The influence of PEPA on the flame‐retardant properties of PA6 was investigated using the limiting oxygen index (LOI), the Underwriters Laboratories UL‐94 test, and the cone calorimeter method. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy, X‐ray photoelectron spectroscopy, thermogravimetry (TG), and TG‐FTIR were conducted to study the influence of PEPA on the thermal decomposition and the mechanism of performance of PA6 from products of condensed and gaseous phases. The results show that the LOI value and the content of residual char of PA6/PEPA composites increased with increasing PEPA content, and an LOI value of 38% could be reached when the feed ratio of PEPA was 30 wt %. The average heat release rate and total heat release drastically decreased with increasing content of PEPA, and the amount of carbon residue increased by 52.9% over neat PA6 after TG tests. The inorganic acid produced by PEPA during combustion can be used as an acid source to promote the dehydration of PA6 and the processes of esterification crosslinking, arylation, and carbonization. Moreover, there was less CO₂ released than by PA6, and more carbon‐containing compound remained in the composites so that a stable carbon layer structure was formed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46236.     

E-300与MOCA扩链聚氨酯弹性体的力学性能比较

以聚酯(PEA、PEPA、PCL)或聚醚(PTMG、PPG、PO/PT)和TDI为原料合成聚氨酯(PU)预聚体,分别用MOCA和E-300作扩链剂制备聚氨酯弹性体。比较了这2种扩链剂对PU弹性体力学性能的影响。实验结果表明:MOCA-PU的硬度、模量和强度均大于E-300-PU,E-300-PU的扯断伸长率略高于MOCA-PU。在相同硬度下的聚醚型PU弹性体,E-300-PU比MOCA-PU的撕裂强度高。     

聚氨酯弹性体的动态力学性能的影响因素

综述了聚氨酯弹性体动态力学性能的多种影响因素,讨论了软段类型(聚酯和聚醚)、软段相对分子质量、硬段类型(二异氰酸酯和扩链剂)、硬软段质量分数对PU弹性体动态力学性能的影响。在PU弹性体中,聚酯软段比聚醚软段的Tg高,弹性模量依PPG、PEG、PTMG软段顺序增加。     

Waterborne polysiloxane–urethane–urea for potential marine coatings

Waterborne polysiloxane–urethane–ureas (WBPSUU) were prepared through a prepolymer process using siloxane polyol, namely polydimethylsiloxane (PDMS) and polyether polyol, namely poly(tetramethyleneoxide glycol) (PTMG) as the soft segments. The goal of this study was to explore the potential use of polysiloxane–urethane–urea in marine coatings in order to boost the flexibility, adhesion, erosion, and foul-release property with respect to PDMS/PTMG ratio (PDMS wt%). The structural elucidation of the synthesized waterborne polyurethane and WBPSUU was carried out by FTIR, ¹H NMR, and ²⁹Si NMR spectroscopic techniques. The XPS and AFM analyses indicate that the polymer surface can be silicone enriched with the optimum PDMS content (15.76 wt%). The antifouling property of the coatings was investigated by the immersion test under a marine environment for 90 days. The fouled area was calculated for all the samples and the fouled area (%) decreased with increasing PDMS content. After 90 days the lowest fouled area (5%) was observed in the sample using WBPSUU4 (PDMS 15.76 wt%) among all of the samples.     

Synergistic effects of aluminum hydroxide on improving the flame retardancy and smoke suppression properties of transparent intumescent fire-retardant coatings

A series of novel aluminum phosphate ester (APEA) flame retardants were synthesized by the salification of cyclic phosphate ester acid (PEA) with different mass ratios of aluminum hydroxide (ATH) and thoroughly characterized by Fourier transform infrared (FTIR) spectroscopy and ¹H nuclear magnetic resonance spectroscopy. The PEA and APEAs were thoroughly mixed with melamine formaldehyde resin to produce five kinds of transparent fire-retardant coatings. The synergistic effects of ATH on the thermal stability, flame retardancy, and smoke suppression properties of the coatings were investigated by different analytical instruments. The results show that the incorporation of ATH greatly decreases the weight loss, char index, flame spread rating, heat release rate, total heat release, smoke production rate, total smoke release and specific optical density in the coatings applied to plywood boards, which is ascribed to a more compact and intumescent char formed during burning, as determined from digital photographs and scanning electron microscopy images. The synergistic effects of ATH in the coatings depend on the content of ATH, and an excessive amount of ATH diminishes the synergistic effects on the flame retardancy and smoke suppression properties based on fire protection tests and cone calorimeter test. Thermo-gravimetric analysis reveals that the thermal stability and char-forming ability of the coatings gradually improve with increasing loading of ATH. FTIR analysis demonstrates that the incorporation of ATH forms a more phosphorus-rich crosslinked char and aromatic char during burning, thus effectively reducing the mass loss, heat release, and smoke production and exhibiting excellent synergistic flame retardant and smoke suppression effects in the coatings.     

膨胀型阻燃剂的疏水改性及对水性阻燃涂料性能的影响

为了提高水性阻燃涂层的耐水性,以环氧树脂(EP)作为包覆材料,分别采用单一组分和混合组分改性两种工艺对阻燃剂〔聚磷酸铵(APP)、三聚氰胺(MEL)和季戊四醇(PER)〕进行包覆改性,制备出了改性阻燃剂及水性阻燃涂层。借助FTIR分析阻燃剂表面基团;采用SEM观察其微观结构;测量阻燃剂的接触角,并对其粒度分布进行统计;借助TG对阻燃剂及水性阻燃涂层进行测试;并参考国标GB/T1733—1993对涂层耐水性进行了测试。结果表明:两种工艺制备的阻燃剂其表面均包覆EP,且EP用量为阻燃剂质量的15%时,疏水效果达到最佳;阻燃剂经改性后其溶解度降低,接触角增大,使水性阻燃涂层耐水性显著提高,且阻燃剂采用混合组分改性效率更高;聚磷酸铵与EP发生交联生成不饱和富碳结构,加固残炭碳骨架的稳定性及增加涂层残余物的质量。     

不同聚醚二元醇软段对光固化水性聚氨酯乳液性能的影响

以不同聚醚二元醇、异佛尔酮二异氰酸酯、2,2-双羟甲基丙酸、甲基丙烯酸-2-羟基乙酯为主要原料,通过丙酮法合成光固化水性聚氨酯(WPU)乳液,讨论了不同聚醚软段对光固化WPU乳液性能的影响.结果表明,由聚四氢呋喃醚二元醇PTMG1000和PTMG2000制备的光固化WPU乳液具有较小的粒径和粘度,其交联后的膜具有较高储...     

纳米SiO2对PP/MPP/PEPA膨胀阻燃体系的协同作用

以纳米SiO,为阻燃协效剂,采用多聚磷酸蜜胺(MPP)和茏状季戊四醇磷酸酯(PEPA)复配阻燃剂,制备具有良好阻燃性能的无卤阻燃聚丙烯(PP).研究纳米SiO2用量对PP阻燃性能和协效作用的影响.结果表明:添加少量的纳米SiO2可提高PP的阻燃性能;当纳米SiO2添加量为1%时,阻燃PP的氧指数达28.5%.TGA和FTIR分析及SEM和体式显微镜观测结果表明:添加少量的纳米SiO2可促进体系成炭,稳定炭层,从而提高材料的阻燃性能.     

Preparation of waterborne polyurethanes using an amphiphilic diol for breathable waterproof textile coatings

The application of polyurethanes (PUs) on breathable waterproof fabric coatings requires a balance of water vapor permeability (WVP) and water resistance which can be achieved by tailoring hydrophilic and hydrophobic segments. PU prepolymers were prepared from isophorone diisocyanate, dimethylol butanoic acid, and a mixture of various ratios of amphiphilic PPG2050 (copolymer of ethylene oxide and propylene oxide with –OH end groups) and hydrophobic poly(tetramethylene ether glycol) (PTMEG). After neutralization with triethylamine, the prepolymers were chain-extended with ethylene diamine/1,4-butanediol (1:1 by molar). The WVP values of the fabric coatings prepared using various waterborne PUs were very similar (910–990 g/m² × 24 h). When waterborne PUs prepared using a mixture of PPG2050 and PTMEG were employed for the textile coatings, the resulting PU-coated textiles exhibited excellent waterproof properties (>10,000 mm H₂O). The textile coatings prepared from PPG2050/PTMEG-based waterborne PUs were significantly more waterproof than those prepared from poly(ethylene glycol) (PEG)/poly(propylene glycol) (PPG)/PTMEG-based waterborne PU. This is probably due to a more even distribution of hydrophobic segments in the PUs, even though the WVP values of the PEG/PPG/PTMEG-based PU coatings were considerably smaller than those of the PPG2050/PTMEG-based PU coatings.     

Preparation of waterborne polyurethanes using an amphiphilic diol for breathable waterproof textile coatings

The application of polyurethanes (PUs) on breathable waterproof fabric coatings requires a balance of water vapor permeability (WVP) and water resistance which can be achieved by tailoring hydrophilic and hydrophobic segments. PU prepolymers were prepared from isophorone diisocyanate, dimethylol butanoic acid, and a mixture of various ratios of amphiphilic PPG2050 (copolymer of ethylene oxide and propylene oxide with –OH end groups) and hydrophobic poly(tetramethylene ether glycol) (PTMEG). After neutralization with triethylamine, the prepolymers were chain-extended with ethylene diamine/1,4-butanediol (1:1 by molar). The WVP values of the fabric coatings prepared using various waterborne PUs were very similar (910–990 g/m² × 24 h). When waterborne PUs prepared using a mixture of PPG2050 and PTMEG were employed for the textile coatings, the resulting PU-coated textiles exhibited excellent waterproof properties (>10,000 mm H₂O). The textile coatings prepared from PPG2050/PTMEG-based waterborne PUs were significantly more waterproof than those prepared from poly(ethylene glycol) (PEG)/poly(propylene glycol) (PPG)/PTMEG-based waterborne PU. This is probably due to a more even distribution of hydrophobic segments in the PUs, even though the WVP values of the PEG/PPG/PTMEG-based PU coatings were considerably smaller than those of the PPG2050/PTMEG-based PU coatings.     

Study on flame retardancy of APP/PEPA/MoO3 synergism in vinyl ester resins

A range of flame retardant vinyl ester resins (VERs) samples have been produced containing different contents of PEPA (1-oxo-4-hydroxymethyl-2,6,7-trioxa-l-phosphabicyclo[2.2.2]octane), APP (ammonium polyphosphate), and MoO₃ (molybdenum trioxide). By investigating the flame retardancy of VER samples such as limiting oxygen index and UL-94, the synergistic flame retardance of APP, PEPA, and MoO3 has been revealed. The cone calorimeter is an instrument that measures the combustion data of samples. In the VER composites on fire, the synergistic smoke suppression effect of the APP, PEPA, and MoO₃ was detected. The gas and condensed phase of VER composites with APP, PEPA, and MoO₃ were tested by the thermogravimetric analysis (TGA)–Fourier transform infrared spectroscopy (FTIR) and FTIR. The char residues of samples have been studied at length by scanning electron microscopy and FTIR. The results show that the presence of MoO3 can promote the formation of P O and PO structures.     

Study of the Miscibility of Hard and Soft Segments of Optically Active Poly(amide-imide-ether-urethane) Copolymers based-L-Leucine with Different Soft Segments

Summary Three series of new optically active poly(amide-imide-ether-urethane) (PAIEU) copolymers with different soft segments including polyethylene glycol (PEG), polypropylene glycol (PPG) or polytetramethylene glycol (PTMG) of molecular weight (MW) of 1000 were successfully synthesized. These copolymers were prepared via direct polycondensation reaction of an aromatic diacid based on L-leucine (1), 4,4’-methylene-bis-(4-phenylisocyanate) (MDI) (2) and different polyether polyols. FTIR spectroscopy shows the different absorption bands of NH, urethane and imide-I, II groups that suggests the different intermolecular interactions due to hydrogen bonding in these PAIEUs. On the other hand, DSC analysis reveals that the glass transition temperature for hard segments (Tgh) of PAIEUs based on polyethers with higher ratio of O/CH₂ is higher than that of polyethers with lower ratio of O/CH₂ and it decreases with the soft segment length in PAIEUs consisting of the same type of PEG soft segments.     

Thermal degradation of flame‐retarded polyethylene/magnesium hydroxide/poly(ethylene‐co‐propylene) elastomer composites

Magnesium hydroxide‐based halogen‐free flame retarded linear low‐density polyethylene (LLDPE) composites containing poly(ethylene‐co‐propylene) (EP) elastomer were prepared by a melt process and subsequently vulcanized thermally. The thermal degradation of the composites was studied using thermogravimetric (TG) analysis and real‐time Fourier transform infrared (RT‐FTIR) spectroscopy. The combustion residues from the composites were characterized by Raman spectroscopy and X‐ray photoelectron spectroscopy (XPS). The results from TG and RT‐FTIR tests show that the incorporation of a suitable amount of the elastomer into polyethylene/magnesium hydroxide composites after vulcanization increases the thermal stability. A graphite‐like char was found for the composites with EP elastomer, from Raman spectroscopy studies. XPS results indicate that there are several forms of carbon present in the combustion residues of the composites with EP elastomer, compared with only one form of carbon in the residues of the composites without the elastomer. Copyright © 2003 Society of Chemical Industry     

Microwave dielectric relaxation and molecular dynamics in binary mixtures of poly(propylene glycol) 2000 and poly(ethylene glycol)s of varying molecular weight in dilute solution

Molecular dynamics of binary mixtures of poly(propylene glycol) (PPG) and poly(ethylene glycol)s (PEGs) of varying molecular weight due to molecular interactions, chain coiling and elongation in dilute solution under various conditions, ie varying number of monomer units of PEG, method of mixing of polymers and solvent environment, has been explored using microwave dielectric relaxation times. The average relaxation time τ_o, relaxation time corresponding to segmental motion τ₁ and group rotations τ₂, of a series of binary mixtures of poly(propylene glycol) 2000 and poly(ethylene glycol) of varying molecular weight (ie PPG 2000 + PEG 200, PPG 2000 + PEG 300, PPG 2000 + PEG 400, and PPG 2000 + PEG 600 mixed by equal volume in the pure liquid states, and PPG 2000 + PEG 1500, PPG 2000 + PEG 4000 and PPG 2000 + PEG 6000 mixed equal weights in solvent) have been determined in dilute solution in benzene and carbon tetrachloride at 10.10 GHz and 35 °C. A comparison of the results of these binary systems of highly associating molecules shows that the molecular dynamics corresponding to rotation of a molecule as a whole and segmental motion in dilute solutions are governed by the solvent density when the solutes are mixed in their pure liquid state. Furthermore, the molecular motion is independent of solvent environment when the polymers are added separately in the solvent for the preparation of binary mixtures. It has also been observed that there is a systematic elongation of the dynamic network of the species formed during mixing of pure liquid polymers in lighter environment of solvent with increasing PEG monomer units, while the elongation behaviour of the same species in the heavier environment of carbon tetrachloride solvent is in contrast to the elongation behaviour of the polymeric species formed in pure PEG. The role of rotating methyl side‐groups in the PPG molecular chain has been discussed in term of the breaking and reforming of hydrogen bonds in complex polymeric species for the segmental motion. In all these mixtures, the relaxation time corresponding to group rotations is independent of the solvent environment and constituents of the binary mixtures. The effect of chain flexibility and coiling in these binary mixtures is discussed by comparing the relaxation times of the mixtures with their individual relaxation times in dilute solutions measured earlier in this laboratory. © 2001 Society of Chemical Industry     

磷腈/三嗪双基分子复配阻燃聚乳酸

将磷腈/三嗪双基分子阻燃剂（HTTCP）分别与六苯氧基环三磷腈（HPCTP）和季戊四醇磷酸酯（PEPA）按不同配比复配,采用熔融共混法制备了阻燃聚乳酸（PLA）的复合材料。采用热失重分析仪、极限氧指数仪、垂直燃烧试验箱和锥形量热仪研究了2种复配阻燃体系及其配比对PLA阻燃复合材料热稳定性和阻燃性能的影响,并采用扫描电子显微镜对材料的残炭形貌进行了分析,探究了其阻燃机理。结果表明,PEPA/HTTCP复配阻燃剂的阻燃效果优于HPCTP/HTTCP复配阻燃剂。当PEPA/HTTCP的质量比为3/1,总添加量为20 %时,阻燃PLA的极限氧指数最高,为27.2 %,热释放速率峰值、平均热释放速率以及热释放总量达到最小值,且能够达到UL 94 V-0级。     

Polyurethane coatings based on linseed oil phosphate ester polyols with intumescent flame retardants

The effect of intumescent flame retardants on the properties of polyurethane (PU) coatings based on 2 kinds of phosphate ester polyol was studied. Synthesizing polyols, phosphorylation of epoxidized linseed oil with phosphoric acid was performed in the presence of isopropyl alcohol (IPA polyol) or diethylene glycol butyl ether (DGBE polyol). The obtained polyols were characterized by Fourier transform infrared (FTIR) and ³¹P nuclear magnetic resonance (NMR) spectroscopy. The properties of neat PU coatings based on 2 polyols and those filled with different content (up to 25 wt%) of melamine (Mel), ammonium polyphosphate (APP), and expandable graphite (EG) were studied using thermal gravimetric analysis (TGA), and tensile and cone calorimeter tests. It was found that IPA polyol contained not only phosphate monoesters and diesters, as DGBE polyol, but also phosphate triester and pyrophosphate monoester. Due to this difference, IPA neat and filled coatings had higher tensile characteristics and char residue in a TGA test. Also, the flame retardancy of IPA coatings, compared with that of DGBE coatings, was higher. In a cone calorimeter test, coatings filled with Mel showed a small increase of flame retardancy, but the total smoke release (TSR) of wood samples with coatings decreased noticeably. The effect of APP on the flame retardancy of coatings was higher, but in contrast, the TSR of samples increased with increasing APP content. Even greater decrease of flammability parameters and a simultaneous significant decrease of TSR were shown by the samples with IPA coatings filled with EG.     

封端型水性聚氨酯的合成与研究

以异佛尔酮二异氰酸酯(IPDI)、二羟甲基丙酸(DMPA)、聚醚多元醇(PPG、PTMG、PEG)等为主要原料进行反应,分别采用亚硫酸氢钠(NaHSO3)和甲乙酮肟(MEKO)封端,合成了系列水性聚氨酯乳液。讨论了多元醇类型及配比、不同封端剂对水性聚氨酯乳液及胶膜性能的影响。结果表明,由PPG-220合成的水性聚氨酯具有较好的耐水性,由PTMG2000合成的水性聚氨酯具有优异的力学性能,当PPG-220∶PTMG2000摩尔比为3∶1复配使用时所得的水性聚氨酯能达到优良的综合性能。以NaHSO3为封端剂其成膜性较好,解封温度为60.5~68.0℃;以MEKO为封端剂其稳定性较好,解封温度为110~124℃。