Synthesis and thermal decomposition of a novel hyperbranched polyphosphate ester used for flame retardant systems

A novel hyperbranched polyphosphate ester (HPPE) was synthesized via the polycondensation of bisphenol-A as an A₂ monomer and phosphoryl trichloride as a B₃ monomer at 100 °C, without gelation. The initial molar ratio of A₂ to B₃ was set to be 1.5:1. The final product was precipitated from methanol. ³¹P NMR spectroscopy was used to monitor the reaction. The formed HPPE was characterized by FTIR and ¹H NMR to confirm its end groups. Differential scanning calorimetry data revealed that the cured bisphenol-A epoxy resin with HPPE as a curing agent possessed improved glass transition temperature. Dynamic mechanical thermal analysis also showed the increase in the glass transition temperature. The thermal degradation properties and flame retardancy were investigated by thermogravimetric analysis and limiting oxygen index (LOI). The results showed that the incorporation of HPPE into bisphenol-A epoxy resin increased its thermal stability and char yield during the decomposition by raising the second stage decomposition temperature. The LOI value increased from 23 to 31 when HPPE, instead of bisphenol-A, was used as a curing agent.     

Synthesis and characterization of P/Si flame retardant and its application in epoxy systems

In this report, a novel phosphorus/silicon‐containing reactive flame retardant, hexa(3‐triglycidyloxysilylpropyl)triphosphazene (HGPP), was synthesized and characterized by Fourier transform infrared spectrometry and nuclear magnetic resonance spectra (¹H, ³¹P, and ²⁹Si), respectively. To prepare cured epoxy, HGPP had been co‐cured with diglycidyl ether of bisphenol‐A (DGEBA) via 4,4‐diaminodiphenylsulfone as a curing agent. The mechanical, thermal, and flame retardant properties of the cured epoxy were evaluated by dynamic mechanical analysis, thermogravimetric analysis, and limiting oxygen index (LOI). According to these results, it could be found that incorporation of HGPP in the cured epoxy system showed good thermal stability, high LOI values, and high char yield at high temperature. As moderate loading of HGPP in the epoxy system, its storage modulus and glass transition temperature were higher than those of neat DGEBA. Copyright © 2011 John Wiley & Sons, Ltd.     

Synthesis and properties of phosphorus-containing bio-based epoxy resin from itaconic acid

A phosphorus-containing bio-based epoxy resin (EADI) was synthesized from itaconic acid (IA) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO). As a matrix, its cured epoxy network with methyl hexahydrophthalic anhydride (MHHPA) as the curing agent showed comparable glass-transition temperature and mechanical properties to diglycidyl ether in a bisphenol A (DGEBA) system as well as good flame retardancy with UL94 V-0 grade during a vertical burning test. As a reactive flame retardant, its flame-resistant effect on DGEBA/MHHPA system as well as its influence on the curing behavior and the thermal and mechanical properties of the modified epoxy resin were investigated. Results showed that after the introduction of EADI, not only were the flame retardancy determined by vertical burning test, LOI measurement, and thermogravimetric analysis significantly improved, but also the curing reactivity, glass transition temperature (T _g), initial degradation temperature for 5% weight loss (T _d(5%)), and flexural modulus of the cured system improved as well. EADI has great potential to be used as a green flame retardant in epoxy resin systems.     

A flame‐retardant phosphate and cyclotriphosphazene‐containing epoxy resin: Synthesis and properties

A novel flame‐retardant epoxy resin, (4‐diethoxyphosphoryloxyphenoxy)(4‐glycidoxyphenoxy)cyclotriphosphazene (PPCTP), was prepared by the reaction of epichlorohydrin with (4‐diethoxyphosphoryloxyphenoxy)(4‐hydroxyphenoxy)cyclotriphosphazene and was characterized by Fourier transform infrared, ³¹P NMR, and ¹H NMR analyses. The epoxy resin was further cured with diamine curing agents, 4,4′‐diaminodiphenylmethane (DDM), 4,4′‐diaminodiphenylsulfone (DDS), dicyanodiamide (DICY), and 3,4′‐oxydianiline (ODA), to obtain the corresponding epoxy polymers. The curing reactions of the PPCTP resin with the diamines were studied by differential scanning calorimetry. The reactivities of the four curing agents toward PPCTP were in the following order: DDM > ODA > DICY > DDS. In addition, the thermal properties of the cured epoxy polymers were studied by thermogravimetric analysis, and the flame retardancies were estimated by measurement of the limiting oxygen index (LOI). Compared to a corresponding Epon 828‐based epoxy polymer, the PPCTP‐based epoxy polymers showed lower weight‐loss temperatures, higher char yields, and higher LOI values, indicating that the epoxy resin prepared could be useful as a flame retardant. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 972–981, 2000     

Thermal and flame retardant properties of epoxy resin cured by a novel phosphorus-containing 4,4′-bisphenol novolac curing agent

A novel flame retardant curing agent for epoxy resin (EP), i.e., a DOPO (9,10-dihydro-9-oxa-10-phosphaphenan-threne-10-oxide)-containing 4,4'-bisphenol novolac (BIP-DOPO) was synthesized and characterized by Fourier transform infrared (FTIR), ¹H NMR, ³¹P NMR spectroscopy, and gel permeation chromatography. The epoxy resin cured by BIP-DOPO itself or its mixture with a commonly used bisphenol A-formaldehyde novolac resin (NPEH720) was prepared. The flame retardancy of the cured EP thermosets were studied by limiting oxygen index (LOI), UL 94 and cone calorimeter test (CCT), and the thermal properties by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The results show that the cured epoxy resin EPNP/BI/3/1, which contains 2.2% phosphorus, possesses a value of 26.2% and achieves the UL 94 V-0 rating. The data from cone calorimeter test demonstrated that the peak release rate, average heat release rate, total heat release decline sharply for the flame retarded epoxy resins, compared with those of pure ones. DSC results show that the glass-transition temperatures of cured epoxy resins decrease with increasing phosphorus content. TGA indicates that the incorporation of BIP-DOPO promotes the decomposition of epoxy resin matrix ahead of time and leads to higher char yield. The surface morphological structures of the char residues reveal that the introduction of BIP-DOPO benefits to the formation of a continuous and solid char layer on the epoxy resin material surface during combustion.     

Synthesis of a novel phosphorus‐containing curing agent and its effects on the flame retardancy,thermal degradation and moisture resistance of epoxy resins

A novel phosphorus‐containing compound diphenyl‐(1, 2‐dicarboxylethyl)‐phosphine oxide defined as DPDCEPO was synthesized and used as a flame retardant curing agent for epoxy resins (EP). The chemical structure of the prepared DPDCEPO was well characterized by Fourier transform infrared spectroscopy, and ¹H, ¹³C and ³¹P nuclear magnetic resonance. The DPDCEPO was mixed with curing agent of phthalic anhydride (PA) with various weight ratios into epoxy resins to prepare flame retardant EP thermosets. The flame retardant properties, combustion behavior and thermal analysis of the EP thermosets were respectively investigated by limiting oxygen index (LOI), vertical burning tests (UL‐94), cone calorimeter measurement, dynamic mechanical thermal analysis and thermogravimetric analysis (TGA) tests. The surface morphologies and chemical compositions of the char residues for EP thermosets were respectively investigated by scanning electron microscopy and X‐ray photoelectron spectroscopy (XPS). The water resistant properties of the cured EP were evaluated by putting the samples into distilled water at 70°C for 168 hr. The results revealed that the EP/20 wt% DPDCEPO/80 wt% PA thermosets successfully passed UL‐94 V‐0 flammability rating and the LOI value was as high as 33.2%. The cone test results revealed that the incorporation of DPDCEPO effectively reduced the combustion parameters of the epoxy resin thermosets, such as heat release rate and total heat release. The dynamic mechanical thermal analysis test demonstrated that the glass transition temperature (Tg) decreased with the increase of DPDCEPO content. The TGA results indicated that the incorporation of DPDCEPO promoted the decomposition of epoxy resin matrix ahead of time and led to a higher char yield and thermal stability at high temperatures. The surface morphological structures and analysis of the XPS of the char residues of EP thermosets revealed that the introduction of DPDCEPO benefited the formation of a sufficient, compact and homogeneous char layer with rich flame retardant elements on the epoxy resin material surface during combustion. The mechanical properties and water resistance of the cured epoxy resins were also measured. After water resistance tests, the EP/20 wt% DPDCEPO/80 wt% PA thermosets retained excellent flame retardancy, and the moisture adsorption of the EP thermosets decreased with the increase of DPDCEPO content in EP thermosets because of the existence of the P–C bonds and the rigid aromatic hydrophobic structure in DPDCEPO. Copyright © 2015 John Wiley & Sons, Ltd.     

Synthesis, characterization and properties of the polysiloxane-based episulfide resin

The polysiloxane episulfide resin (PSER) was synthesized through replacement of the oxygen atoms in 1,3,5,7-tetra-(3-glycidoxypropyl) tetramethylcyclotetrasiloxane (TGCS) with sulfur atoms using potassium thiocyanate (KSCN). It was characterized by FT-IR, ¹H NMR, MS and elemental analysis. The PSER resin was a low viscosity liquid, stable at room temperature. The polysiloxane episulfide resin was very reactive: a mixture of PSER and isophorondiamine gelated in a few seconds at room temperature. When m-phenylenediamine (m-PDA) or 2-ethyl-4-methylimidazole (2E4MZ) was used as curing agent, PSER exhibited higher reactivity compared with the parent polysiloxane epoxy resin. The reaction heat of the PSER resin was much lower in comparison with TGCS. The cured polysiloxane episulfide resin showed higher glass transition temperature and much lower water absorption, while the thermal stability was lower. It was found that methylhexahydrophthalic anhydride (MeHHPA) is not effective for curing the episulfide resin, although it is commonly used for curing epoxy resins.     

Synthesis and properties of a phosphorus-containing flame retardant epoxy resin based on bis-phenoxy (3-hydroxy) phenyl phosphine oxide

A reactive phosphorus-containing compound, bis-phenoxy (3-hydroxy) phenyl phosphine oxide (BPHPPO) was first successfully synthesized to produce the phosphorus-containing flame retardant epoxy resin (BPHPPO-EP). The chemical structures were characterized from FTIR, MS, NMR spectra and elemental analyses. Thermal degradation behaviors and flame retardant properties of the cured epoxy resins were investigated from the thermogravimetric analysis (TGA) and the limiting oxygen index (LOI) test using 4,4′-diaminodiphenylsulfone (DDS) as curing agent. The high char yields and the high limiting oxygen index values were found to certify the great flame retardancy of this phosphorus-containing epoxy resin.     

Studies on the effect of different levels of toughener and flame retardants on thermal stability of epoxy resin

A thermoplastic toughener, polyether sulphone (PES) and a number of different types of flame retardants were blended in different ratios with a commercial epoxy resin triglycidyl-p-aminophenol (TGAP) and 4,4-diamino diphenyl sulphone (DDS) a curing agent. The effect of type and levels of flame retardants (FR) and the toughening agent on the curing, thermal decomposition and char oxidation behaviour of the epoxy resin was studied by the simultaneous differential thermal analysis and thermogravimetric techniques. It was observed that the toughener slightly increases the curing temperature (by up to 20 °C) but had minimal effect on the decomposition temperature of the resin. Flame retardants, however affected all stages depending upon the type of flame retardant used. The curing peak for samples containing tougher and flame retardants although slightly changed depending upon the type of FR, was not more than ± 20 °C compared to that of samples containing toughener only. All flame retardants lowered the decomposition temperature of the epoxy resin. Phosphorus- and nitrogen-containing flame retardants reduced the char oxidation leading to more residual char, whereas halogen- containing flame retardants had less effect on this stage.     

Preparation of Poly(phosphoric acid piperazine) and Its Application as an Effective Flame Retardant for Epoxy Resin

A phosphorus-nitrogen containing flame retardant additive of poly(phosphoric acid piperazine),defined as PPAP,was synthesized by the salt-forming reaction between anhydrous piperazine and phosphoric acid,and the dehydration polymerization under heating in nitrogen atmosphere.Its chemical structure was well characterized by Fourier transform infrared (FTIR) spectroscopy,13C and 31p solid-state nuclear magnetic resonance measurements.The synthesized PPAP and curing agent m-phenylenediamine were blended into epoxy resin (EP) to prepare flame retardant EP thermosets.The effects of PPAP on the fire retardancy and thermal degradation behavior of cured EP/PPAP composites were investigated by limiting oxygen index (LOI),vertical burning (UL-94),thermogravimetric analysis/infrared spectrometry (TG-IR) and cone calorimeter tests.The morphologies and chemical compositions of char residues for cured epoxy resin were investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS),respectively.The results demonstrated that the flame retardant EP thermosets successfully passed UL-94 V-0 flammability rating and the LOI value was as high as 30.8％ when incorporating 5wt％ PPAP into the EP thermosets.The TGA results indicated that the synthesized PPAP flame retardant additive possessed high thermal stability and excellent charring capability.Meanwhile,the incorporation of PPAP stimulated the epoxy resin matrix to decompose and charring ahead of time due to its catalytic decomposition effect,which led to a higher char yield at high temperature.The morphological structures and the analysis results of XPS for char residues of EP thermosets revealed that the introduction of PPAP benefited the formation of a sufficient,more compact and homogeneous char layer containing phosphorus-nitrogen flame retardant elements on the material surface during combustion.The formed char layer with high quality effectively prevented the heat transmission and diffusion,limited the production of combustible gases,and inhibited the emission of smoke,leading to the reduction of heat and smoke release.     

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.     

Synthesis and thermal characterization of phosphorus containing siliconized epoxy resins

Siliconized epoxy matrix resin was developed by reacting diglycidyl ethers of bisphenol A (DGEBA) type epoxy resin with hydroxyl terminated polydimethylsiloxane (silicone) modifier, using γ-aminopropyltriethoxysilane crosslinker and dibutyltindilaurate catalyst. The siliconized epoxy resin was cured with 4, 4-diaminodiphenylmethane (DDM), 1,6-hexanediamine (HDA), and bis (4-aminophenyl) phenylphosphate (BAPP). The BAPP cured epoxy and siliconized epoxy resins exhibit better flame-retardant behaviour than DDM and HDA cured resins. The thermal stability and flame-retardant property of the cured epoxy resins were studied by thermal gravimetric analysis (TGA) and limiting oxygen index (LOI). The glass transition temperatures (T_g) were measured by differential scanning calorimetry (DSC) and the surface morphology was studied by scanning electron microscopy (SEM). The heat deflection temperature (HDT) and moisture absorption studies were carried out as per standard testing procedure. The thermal stability and flame-retardant properties of the cured epoxy resins were improved by the incorporation of both silicone and phosphorus moieties. The synergistic effect of silicone and phosphorus enhanced the limiting oxygen index values, which was observed for siliconized epoxy resins cured with phosphorus containing diamine compound.     

A Well-Defined Cyclotriphosphazene-Based Epoxy Monomer and Its Application as A Novel Epoxy Resin: Synthesis,Curing Behaviors,and Flame Retardancy

Abstract

A novel cyclotriphosphazene-based epoxy monomer, hexa-[4-(glycidyloxycarbonyl) phenoxy]cyclotriphosphazene (HGCP), was synthesized via a four-step synthetic route, and fully characterized by ¹H, ¹³C, and ³¹P NMR spectroscopy, high-resolution mass spectrometry, and elemental analysis. Thermosetting systems based on HGCP with three curing agents, for example, 4,4′-diaminodiphenylsulfone (DDS), 4,4′-diaminodiphenylmethane (DDM), and dicyandiamide (DICY), were used for making a comparison of their thermal curing behaviors. The curing behaviors were measured by differential scanning calorimetry. Moreover, flame retardancy of HGCP thermosetting systems was estimated by Limiting Oxygen Index (LOI) and Vertical Burning Test (UL-94). The resulting HGCP thermosetting systems exhibited better flame retardancy than the common epoxy resins diglycidyl ether of bisphenol A (DGEBA) and the regular brominated bisphenol A epoxy resin (TBBA) cured by DDS, respectively. When HGCP was cured by DDS, its thermosetting system gave the most char residues, met the UL-94 V-0 classification, and had a limiting oxygen index value greater than 35.     

Synthesis,Characterization of Phosphorus ContainingDiamide-diimide-tetraamines Based on L-TryptophanAmino Acid and Their Effect on Flame Retardancy ofEpoxy Resins简

The curing behavior of diglycidyl ether of bisphenol-A(DGEBA) with different phosphorus containing diamidediimide-tetraamines(DADITAs) was studied by DSC. Eight DADITAs of varying structures were synthesized by reacting 1 mole of pyromellitic anhydride(PMDA)/3,3′-benzophenone tetracarboxylic dianhydride(BTDA)/1,4,5,8-naphthalene tetracarboxylic dianhydride(NTDA)/4,4′-oxydiphthalic anhydride(ODPA) with 2 mole of L-tryptophan(T) in a mixture of acetic acid and pyridine(3:2 V/V) followed by activaton with thionyl chloride and then condensation with excess of phosphorus containing triamines tris(3-aminophenyl) phosphine(TAP) and tris(3-aminophenyl) phosphine oxide(TAPO). DADITAs obtained by reacting PMDA/BTDA/NTDA/ODPA with L-tryptophan followed by condensation with TAP/TAPO were designated as PTAP, PTAPO, BTAP, BTAPO, NTAP, NTAPO, OTAP and OTAPO respectively. The structural characterization of synthesized DADITAs was done by FTIR,1H-NMR,13C-NMR,31P-NMR spectroscopic techniques and elemental analysis. Thermal stability of the isothermally cured epoxy was investigated using dynamic thermogravimetry analysis. The glass transition temperature(Tg) was highest in DGEBA cured using PTAP. All epoxy thermosets exhibited excellent flame retardancy, moderate changes in Tg and thermal stability. Due to presence of phosphorus in curing agents, all epoxy resin systems met the UL-94 V-0 classification and the limiting oxygen index(LOI) reached up to 38.5, probably because of the nitrogen-phosphorus synergistic effect.     

Kinetics and thermal properties of epoxy resins based on bisphenol fluorene structure

The fluorene-containing epoxy, diglycidyl ether of 9,9-bis(4-hydroxyphenyl) fluorene (DGEBF) was synthesized by a two-step reaction procedure. In order to investigate the relationship between fluorene structure and material properties, DGEBF and a commonly used diglycidyl ether of bisphenol A (DGEBA) were cured with 4,4-diaminodiphenyl methane (DDM) and 4,4-(9-fluorenylidene)-dianiline (FDA). The curing kinetics, thermal properties and decomposition kinetics of these four systems (DGEBA/DDM, DGEBF/DDM, DGEBA/FDA, and DGEBF/FDA) were studied in detail. The curing reactivity of fluorene epoxy resins was lower, but the thermal stability was higher than bisphenol A resins. The onset decomposition temperature of cured epoxy resins was not significantly affected by fluorene structure, but the char yield and T_g value were increased with that of fluorene content. Our results indicated that the addition of fluorene structure to epoxy resin is an effective method to improve the thermal properties of resins, but excess fluorene ring in the chain backbone can depress the curing efficiency of the resin.     

Curing and thermal behaviour of a flame retardant cycloaliphatic epoxy resin based on phosphorus containing poly(amide–imide)s

The curing behaviour of 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate was investigated by the dynamic differential scanning calorimetry (DSC) using phosphorus-containing poly(amide–imide)s (PAIs) having free amine groups, 4,4′-diaminodiphenylmethane (PM) and p-phenylenediamine (PA), in the ratio of 1:1. The PAIs were prepared by co-polymerization of diimide–diacid (DIDA) and phosphorus-containing triamines having phenylene moiety. l-Tryptophan and pyromellitic anhydride were used to synthesize DIDA. Triamines used in the synthesis PAIs were tris(3-aminophenyl) phosphine (TAP), tris(3-aminophenyl) phosphine oxide (TAPO) and bis(3-aminophenyl) aminotolyl phosphine (BAP). TAP-, TAPO- and BAP-containing PAIs were designated as PTAP, PTAPO and PBAP, respectively. These PAIs with free amine groups were characterized by FTIR, ¹H NMR, ¹³C NMR spectroscopic techniques and elemental analysis. The mixture of PAIs and PM or/and PA in the ratios of 0:1, 1:0 and 0.5:0.5 was used for investigation. DSC was used to study the curing of epoxy by recording the DSC scans at heating rates of 10 °C min^?1. Thermal stability of epoxy resin cured isothermally was evaluated by recording thermo gravimetric traces in nitrogen atmosphere at the heating rate of 20 °C min^?1. All samples are highly stable, and the 10 % mass loss found was in the range of 335–520 °C. The percent char yield was highest in case of resin sample E/PM/PTAPO. The flame-retardant properties of cured epoxy resins were investigated by the limiting oxygen index test (LOI) and UL94 test. When phosphorus was incorporated in epoxy resin, the epoxy resin system met the UL94 V-0 classification and the LOI reached at 37.8, because of nitrogen–phosphorus synergistic effect.     

Synthesis of a novel epoxy resin containing naphthalene moiety and properties of its cured polymer with phenol novolac

A new epoxy resin (Bis-ENA) containing naphthalene structure linked with a 1,4-bis(isopropylidene)phenylene was synthesized and was confirmed by elemental analysis, infrared spectroscopy, and ¹H nuclear magnetic resonance spectroscopy. To estimate the effect of naphthalene moiety on the cured polymer, an epoxy resin (Bis-EP) having phenyl moiety was synthesized, and curing behaviors of Bis-ENA and Bis-EP with phenol novolac were evaluated by differential scanning calorimetry. The incorporation of naphthalene structure into the resin backbone increased the curing temperature and reduced the curing reactivity. Thermal properties of the cured polymers obtained from Bis-ENA and Bis-EP with phenol novolac were examined by thermomechanical analysis and dynamic mechanical analysis. Mechanical properties and moisture resistance were evaluated by flexural strength, flexural modulus, and moisture absorption measurements. The cured polymer obtained from Bis-ENA showed higher glass transition temperature, higher flexural modulus, lower thermal expansion, and lower moisture absorption than that from Bis-EP. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3063–3069, 1999     

Synthesis and characterisation of epoxy-novolac/bismaleimide networks

Epoxy-novolac resin was modified with 1,1^′-(methylenedi-4,1-phenylene) bismaleimide (BMI), and cured with an aromatic amine. Cure behaviour of these blends was studied using differential scanning calorimetry (DSC). The thermograms indicated a unimodal exothermic peak for blends containing lower percentage of BMI. The cured blends showed much higher glass transition temperatures than that of the unmodified epoxy. Thermal stability of the cured epoxy resin was also improved with BMI addition. A homogeneous structure (with no phase separation) of the blends was confirmed both by DSC analysis and scanning electron microscopy (SEM).     

含硅磷杂化物环氧树脂固化物性能研究

首先用γ-环氧丙氧基三甲氧基硅烷(KH-560)和亚磷酸二乙酯(DEP)反应的中间产物进行水解缩合反应,合成了一种含磷低聚硅氧烷杂化物.并用FTIR,NMR,GPC对其结构及分子量进行了表征.然后将含磷低聚硅氧烷引入到双酚A环氧树脂(E-54)制备硅磷杂化物环氧树脂的固化物.对这种含硅磷杂化物环氧树脂固化物的性能研究发现其极限氧指数为23～29,DSC分析结果玻璃化转变温度(Tg)可以达到204℃,失重5%的温度(Td)5%比纯E-54提高近20℃.该固化物具有阻燃性能,同时具有较好的热性能。