Vermiculite Filler Modified with Casein,Chitosan, and Potato Protein as a Flame Retardant for Polyurethane Foams

In this study, polyurethane (PU) composite foams were modified with 2 wt.% of vermiculite fillers, which were themselves modified with casein, chitosan, and potato protein. The impact of the fillers on selected properties of the obtained composites, including their rheological (foaming behavior, dynamic viscosity), thermal (temperature of thermal decomposition stages), flame-retardant (e.g., limiting oxygen index, ignition time, heat peak release), and mechanical properties (toughness, compressive strength (parallel and perpendicular), flexural strength) were investigated. Among all the modified polyurethane composites, the greatest improvement was noticed in the PU foams filled with vermiculite modified with casein and chitosan. For example, after the addition of modified vermiculite fillers, the foams’ compressive strength was enhanced by ~6–18%, their flexural strength by ~2–10%, and their toughness by ~1–5%. Most importantly, the polyurethane composites filled with vermiculite filler and modified vermiculite fillers exhibited improved flame resistance characteristics (the value of total smoke release was reduced by ~34%, the value of peak heat release was reduced by ~25%).     

Mechanically Strong Polyurethane Composites Reinforced with Montmorillonite-Modified Sage Filler (Salvia officinalis L.)

Rigid polyurethane (PUR) foams reinforced with 1, 2, and 5 wt.% of salvia filler (SO filler) and montmorillonite-modified salvia filler (MMT-modified SO filler) were produced in the following study. The impact of 1, 2, and 5 wt.% of SO filler and MMT-modified SO filler on the morphological, chemical, and mechanical properties of PUR composites were examined. In both cases, the addition of 1 and 2 wt.% of SO fillers resulted in the synthesis of PUR composites with improved physicomechanical properties, while the addition of 5 wt.% of SO fillers resulted in the formation of PUR composites with a less uniform structure and, therefore, some deterioration in their physicomechanical performances. Moreover, the results showed that the modification of SO filler with MMT improved the interphase compatibility between filler surface and PUR matrix. Therefore, such reinforced PUR composites were characterized by a well-developed closed-cell structure and improved mechanical, thermal, and flame-retardant performances. For example, when compared with reference foam, the addition of 2 wt.% of MMT-modified SO filler resulted in the formation of PUR composites with greater mechanical properties (compressive strength, flexural strength) and improved dynamic-mechanical properties (storage modulus). The PUR composites were characterized by better thermal stability as well as improved flame retardancy—e.g., decreased peak rate of heat release (pHRR), reduced total smoke release (TSR), and increased limiting oxygen index (LOI).     

Biobased Polyurethane Composite Foams Reinforced with Plum Stones and Silanized Plum Stones

In the following study, ground plum stones and silanized ground plum stones were used as natural fillers for novel polyurethane (PUR) composite foams. The impact of 1, 2, and 5 wt.% of fillers on the cellular structure, foaming parameters, and mechanical, thermomechanical, and thermal properties of produced foams were assessed. The results showed that the silanization process leads to acquiring fillers with a smoother surface compared to unmodified filler. The results also showed that the morphology of the obtained materials is affected by the type and content of filler. Moreover, the modified PUR foams showed improved properties. For example, compared with the reference foam (PUR_REF), the foam with the addition of 1 wt.% of unmodified plum filler showed better mechanical properties, such as higher compressive strength (~8% improvement) and better flexural strength (~6% improvement). The addition of silanized plum filler improved the thermal stability and hydrophobic character of PUR foams. This work shows the relationship between the mechanical, thermal, and application properties of the obtained PUR composites depending on the modification of the filler used during synthesis.     

Investigation on flammability of rigid polyurethane foam‐mineral fillers composite

This study investigates the incorporation of castor oil–based rigid polyurethane foam with mineral fillers feldspar or kaolinite clay in order to enhance the mechanical, thermal, and flame retardant properties. Influence of mineral fillers on the mechanical strength was characterized by compressive strength and flexural strength measurement. Thermogravimetric analysis (TGA) was performed to diagnose the changes in thermal properties, while cone calorimeter test was performed to ascertain the flame retardancy of the mineral filler–incorporated rigid polyurethane foam composites. Results showed that the foams incorporated with mineral filler demonstrated up to 182% increase in compressive strength and 351% increase in flexural strength. Thermal stability of these composite foams was also found to be enhanced on the incorporation of kaolinite clay filler with an increase in 5% weight loss temperature (T_5%) from 192°C to 260°C. Furthermore, peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) were also found to decreased on the incorporation of mineral filler in the rigid polyurethane foam. So mineral fillers are ascertained as a potential filler to enhance the mechanical, thermal, and flame retardant behaviors of bio‐based rigid polyurethane foam composites.     

超微细Mg(OH)2复合阻燃改性PP-R的研究

研制了超微细Mg(OH)2和少量的十溴联苯醚复配阻燃剂与无规共聚聚丙烯(PP-R)的填充共混复合材料,研究了复配阻燃剂的用量和硅烷偶联剂对复合材料力学性能和阻燃性能的影响。结果表明,复配阻燃剂用量的增加对材料拉伸强度有较明显的影响,用量在10份左右时缺口冲击强度达到最大;用硅烷偶联剂处理的填料可改善复合材料的各项性能。复配阻燃剂显著提高了复合材料的阻燃性能,在用量为15份时,氧指数达到27％;用量超过20份,垂直燃烧性为FV-1级。微量发烟。     

Comparative study of aluminum diethylphosphinate and aluminum methylethylphosphinate‐filled epoxy flame‐retardant composites

Epoxy resin (EP) is one of the main polymers in electrical and electronic applications. In this work, flame‐retardant epoxy resin composites based on aluminum diethylphosphinate (Al(DEP)) and aluminum methylethylphosphinate (Al(MEP) were prepared using aromatic amine 4, 4‐diaminodiphenylmethane as curing agent. The flammability, thermal degradation, flexural properties, and morphologies of composites were investigated with respect to the filler loading and filler type. Results showed that both Al(MEP) and Al(DEP) were efficient flame retardants for EP and a low dosage (15 wt%) is enough to achieve the important criterion UL 94 V‐0. Limiting oxygen index (LOI) of composites is increased with filler loading (phosphorus content) and reached of 32.2% for 15 wt% of Al(MEP) and 29.8 for 15 wt% of Al(DEP). The char formation and flexural modulus of composites are also improved by adding the two fillers. However, the flexural strength of all the composites decreased with increasing filler loading. In comparison with Al(DEP)/EP, Al(MEP)/EP provides a higher flammability, better thermal stability and char formation but inferior flexural properties. Scanning electron microscopy revealed that the dispersion of Al(DEP) filler in the EP matrix is more uniform and exhibits better compatibility with EP matrix, which in turn generates better flexural strength and higher modulus when compared with Al(MEP)‐filled EP composites. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

膨胀型阻燃剂/二乙基次磷酸铝阻燃改性不饱和树脂基复合材料

采用密胺包覆聚磷酸铵（APP）、季戊四醇（PER）和三聚氰胺（MEL）作为膨胀型阻燃剂（IFR）对不饱和树脂（UP）进行改性,研究了APP、PER和MEL不同复配比例及用量对不饱和树脂基复合材料阻燃性能和力学性能的影响。基于IFR最佳用量,以二乙基次磷酸铝（ADP）为协效剂,研究了ADP用量对IFR/UP阻燃复合材料阻燃性能、力学性能及热稳定性的影响。结果表明,当APP∶PER∶MEL复配比例为4∶1∶1,IFR添加量为15 %（质量分数,下同）时,复合材料综合性能最佳,其极限氧指数为27.4 %,UL 94垂直燃烧达到V?1等级,弯曲强度和冲击韧性分别为100.3 MPa和6.3 kJ/m²;ADP的引入能够进一步提高IFR/UP复合材料阻燃性能,且随着ADP质量分数的增加而增强;当ADP质量分数为2 %时,IFR?ADP/UP复合材料极限氧指数为28.5 %并达到V?0阻燃等级,弯曲强度和冲击韧性分别为110 MPa和7.8 kJ/m²,与IFR/UP复合材料相比,分别提高了9.7 %和23.8 %;ADP能够促进IFR/UP复合材料表面成炭,缓解基体的热降解。     

改性勃姆石对聚丙烯性能影响研究

将勃姆石用酞酸酯偶联剂（TC-114）进行活化改性处理,将其与聚丙烯（PP）进行熔融挤出得到PP/改性勃姆石复合材料,采用热重分析仪、差示扫描量热仪、极限氧指数测试仪、锥形量热仪等探究改性后勃姆石对PP性能的影响。结果表明,经过偶联剂处理的勃姆石填充PP后所得的复合材料的弯曲强度与纯PP对比的提高了14.4 %,冲击强度提升了30.6 %,而与未改性勃姆石填充的复合材料比弯曲强度提高了6.9 %,冲击强度提升了5.7 %,且断裂伸长率相较于未改性的复合材料提升4倍;改性勃姆石填充聚丙烯复合材料的熔体流动速率、热稳定性以及极限氧指数相较于纯PP都有较大程度提升;改性后的勃姆石有增强聚丙烯力学性能性能的效果,并且随着填入量的增加,热稳定性和阻燃性能都随之提高。     

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     

Flammability behavior of unsaturated polyesters modified with novel phosphorous containing flame retardants

Two phosphorous containing reactive flame retardants namely Triallyl phosphate (TAP) and diethylene glycol modified tetra‐allyl phosphate (DTAP) are synthesized and incorporated successfully in commercial Unsaturated polyester (UPR) in various amounts (5, 10, and 15 phr) to yield flame retardant unsaturated polyester (FRUPR) composites. The structures of reactive flame retardant monomers are confirmed by FTIR, ¹H‐NMR, and³¹P‐NMR spectroscopy. Further, FRUPR composites are characterized for their mechanical, thermal, and flame retardant properties. It is observed that tensile strength and hardness of composites are enhanced with the addition of flame retardants; however, flexural strength and impact resistance are lowered. Differential Scanning Calorimetry (DSC) study reveals that there is a significant increase in glass transition temperature with the addition of flame retardants suggesting the formation of dense and crosslinked structure in FRUPR composites. Thermal stability and the flame retardant properties are also observed to be improved with the increase in concentration of flame retardant in UPR as evidenced from Thermo‐gravimetric analysis (TGA). Beyond 10 phr concentration of flame retardants, all composites show V‐0 rating on UL‐94 test. Also, increase in phosphorous content in composites leads to gradual improvement in limiting oxygen index values. POLYM. COMPOS., 38:1483–1491, 2017. © 2015 Society of Plastics Engineers     

聚醚醚酮/多壁碳纳米管复合材料力学及阻燃性能研究

通过熔融共混法将聚醚醚酮（PEEK）与多壁碳纳米管(MWCNT)混合,利用模压法制备了MWCNT增强型PEEK复合材料,研究了MWCNT对PEEK性能的影响。结果表明,添加一定比例的MWCNT能够提高PEEK的力学和阻燃性能;当MWCNT含量为5%（质量分数,下同）时,PEEK的弯曲强度提高了53%;当MWCNT含量为1%时,锥形量热法测得的热释放速率峰值最低,燃烧性能指数值最大,热重分析显示初始分解温度较纯PEEK提高了13℃,表明MWCNT有效地提高了PEEK的阻燃和热稳定性能。     

聚氨酯填充型泡沫混凝土复合材料的性能研究

将不同掺量聚氨酯(PU)加入泡沫混凝土(FC),研究聚氨酯填充型泡沫混凝土(FC/PU)复合材料的性能。结果表明:随着PU掺量的增加,FC/PU复合材料的导热系数不断降低,阻燃性能变差。PU掺量为0~4%时,随着PU掺量的增加,FC/PU复合材料的浆体黏度逐渐降低,气孔特性变好,抗压强度不断增大。PU掺量超过4%时,FC/PU复合材料黏度开始增大,气孔特性变差,抗压强度逐渐降低。PU掺量为4%时,FC/PU复合材料的综合性能最优,与未掺入PU相比,黏度降低62.7%,气孔特性较好,抗压强度提高75.0%,导热系数降低18.7%,阻燃性能仍能达到A1级。     

Investigation of mechanical properties of graphene decorated with graphene quantum dot-reinforced epoxy nanocomposite

In this investigation, the mechanical properties such as compression, impact, and flexural properties of graphene decorated with graphene quantum dots (GDGQD) epoxy composites with concentration of GDGQD ranging from 0.25 to 1 wt % were studied. Ideal mechanical properties are obtained by systematically varying the filler weight in the epoxy matrix. The morphological studies of GDGQD have been characterized using transmission electron microscope, X-ray diffraction, and Fourier transform infrared technique. The compression, impact, and flexural strengths were enhanced effectively by the GDGQD loading. With the addition of 0.75 wt % of GDGQD, the compressive strength, compressive modulus, flexural strength, and flexural modulus of the composites were improved by 22, 29, 31, and 63%, respectively. Also an improvement in impact strength of 102% for 0.75 wt % GDGQD epoxy sample was also obtained. Examination of fractured test specimens was performed with scanning electron microscope. The enhancement in the mechanical properties is due to the better stress transfer that is attributed by enhanced interfacial bonding between GDGQDs and the epoxy. Using the GDGQD aspect ratio in the two-dimensional randomly oriented filler modified Halpin–Tsai model, the theoretical flexural modulus for the GDGQD/epoxy composites has been established. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 137, 48680.     

用埃洛石负载氨基磺酸胍制备阻燃丁腈橡胶

以天然埃洛石纳米管（HNTs）作为载体,通过在其管内负载阻燃剂氨基磺酸胍（GAS）得到功能填料HNTs-GAS,以制备低烟无卤阻燃丁腈橡胶（NBR）。采用热重分析计算得到HNTs与GAS的投料质量比为1/3时可达到质量分数6%的最佳负载率。添加122.3份（质量,下同）HNTs-GAS和5.7份GAS的阻燃NBR复合材料的极限氧指数为28.3%,垂直燃烧达到V-1等级,烟密度为105,具有较好的阻燃性。HNTs-GAS的加入能有效提高NBR的力学性能,与添加相同用量HNTs和GAS的NBR相比,添加HNTs-GAS后NBR复合材料的拉伸强度、撕裂强度和扯断伸长率分别提高了47.5%、36.8%和67.1%。     

三聚氰胺聚磷酸盐/硼酚醛协效体系阻燃PA66/GF复合材料的研究

采用氮磷型阻燃剂三聚氰胺聚磷酸盐(MPP)与硼改性酚醛树脂(BPF)组成的复合阻燃体系对玻纤(GF)增强尼龙66( PA66)复合材料进行阻燃,获得了阻燃性能优异、力学性能良好的增强复合材料,研究了协效阻燃剂BPF/MPP配比、BPF/MPP用量及GF用量对阻燃复合材料阻燃性能的影响,采用微型燃烧量热和质量保持率分析方法研究了阻燃复合材料的燃烧及成炭行为,对复合阻燃剂的协效机理进行了讨论.结果表明,当BPF在BPF/MPP中的质量分数为15％时,添加25％ BPF/MPP复合阻燃剂可使20％ GF增强PA66复合材料达到V-0( 1.6 mm)阻燃级别,极限氧指数增加至25.3％,拉伸强度、弯曲强度、缺口冲击强度分别为116 MPa,132 MPa,7.1 kJ/m2.该复合材料可满足高性能无卤阻燃的使用要求.     

Grafting multi-elements hybrid polymer brushes on graphene oxide for epoxy composite with excellent flame retardancy

In this paper, a silicon-oxygen coupling agent (MPS) with a double bond is hydrolyzed with graphene oxide (GO) to obtain MPS-GO. The polymerization of MPS-GO with the phosphorus-containing monomer (HEPO) is initiated with 2,2′-Azobis(2-methylpropionitrile) (AIBN) to obtain multi-elements hybrid polymer brushes grafting graphene oxide (HM-GO). As a flame retardant, different amounts of HM-GO are added to obtain EP composites. In this system, the properties of composite flame retardant obviously increase with the increasing of HM-GO. The limiting oxygen index (LOI) value of composites with 4 wt% addition of HM-GO is 31.0%, while the LOI value of EP-0 is only 23.9%. And the peak heat release rate (PHRR) value is reduced from 515.8 W g⁻¹ of pure epoxy resin to 376.9 W g⁻¹. In addition, with the increase of HM-GO addition, the T_g value, flexural strength and flexural modulus of EP composites are improved. Through calculation, it is proved that the rising of T_g was due to the increase of crosslink density of the system. The flame retardant performance and mechanical properties of the composite materials are steadily improved, indicating that such flame retardants are dispersed well in the epoxy resin. HM-GO is an efficient macromolecular modified graphene oxide halogen-free flame retardant, which can improve both flame retardant properties and mechanical properties.     

Simultaneously Improving the Thermal,Flame‐Retardant and Mechanical Properties of Epoxy Resins Modified by a Novel Multi‐Element Synergistic Flame Retardant

To obtain epoxy resins with satisfactory thermal, flame retardant, and mechanical properties, a novel multi‐element synergistic flame retardant (PPVSZ) is synthesized through the reaction between P? H of 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) and C?C of polysilazane (PVSZ) and utilized as a multi‐element synergistic flame retardant for epoxy resins. The flame retardant mechanism is explored by XPS and SEM, confirming that the excellent flame‐retardance efficiency owes itself to an optimal flame retardant way which jointly exerts the flame‐retardant effects in the gaseous and condensed phase. The thermal properties deduced from DSC, TGA, and DMA, indicate the glass transition temperature, maximum weight loss rate, and char yields at 700 °C for EP‐2 increase by about 5.0 °C, 8.4 °C and 8.8%, respectively. Furthermore, mechanical properties such as impact strength, tensile strength, and flexural strength are also increased by 45.38%, 14.16%, and 17.43%, respectively, which show that the incorporation of PPVSZ does not deteriorate the mechanical properties of modified resin. All the results demonstrate that epoxy resins modified by PPVSZ not only have good effect on the flame retardance, but also have good improvement on thermal and mechanical properties, indicating the potential for applications in many fields requiring fire safety.     

Flame‐retardant materials: synergistic effect of halloysite nanotubes on the flammability properties of acrylonitrile–butadiene–styrene composites

Novel well‐dispersed nanocomposites of halloysite nanotubes and acrylonitrile–butadiene–styrene were prepared. The fire retardancy and thermal stability of these new nanocomposites were improved. A synergistic effect was observed between the halloysite nanotubes and an intumescent flame‐retardant system consisting of ammonium polyphosphate, melamine polyphosphate and pentaerythritol in the acrylonitrile–butadiene–styrene composites. The incorporation of the intumescent flame‐retardant material into the halloysite–polymer nanocomposite system also improved the thermal stability and reduced the peak heat release rate by up to 56.2%, and it significantly reduced the emission of CO and CO₂ gases. The morphology and dispersion of the halloysite nanotubes were characterized using scanning and transmission electron microscopy. The thermal stability and flammability properties were investigated using thermogravimetric analysis and cone calorimeter tests. © 2013 Society of Chemical Industry     

Influence of modified fiber–MHSH hybrids on fire hazards,combustion dynamics,and mechanical properties of flame-retarded poly(butylene succinate) composites

Environmental problems caused by polymers and polymers have historically dominated both academic and industrial attention. Sustainable biodegradable wood-plastic composites (WPCs) as an optimum can solve the environmentally critical problems caused by petroleum-based polymers. However, they are flammable, prone to fire accidents, and often have a contradiction between mechanical performance and flame-retardant properties, which limits their range of applications. Here, we reported a flame-retarded poly(butylene succinate) (PBS) WPC prepared with modified natural fiber-magnesium hydroxide sulfate whisker (MHSH) hybrids and intumescent flame retardant s (IFRs). The mechanical performance, flame-retardant properties , thermal stability, and actual fire simulation parameters of composites were investigated. Owing to the unique composition characteristics of modified cassava dregs-MHSH hybrids, the mechanical properties (70P/23I/5C/2M, flexural strength was 39.2 ± 1.960/MPa, impact strength was 7.95 ± 0.3975/ [KJ/m²]), flame retardant properties (70P/23I/5C/2M, the limiting oxygen index value was 39.6%, UL-94 was V0) and thermal stability of WPC have been improved. Thereby, the balance between mechanical performance and flame retardant properties of biocomposites has been achieved in the practical engineering requirements. Furthermore, cone calorimeter data indicated that modified cassava dregs–MHSH hybrids played a role in improving the fire safety of composites. The total heat release, total smoke produce, toxic gas release, and total oxygen consumed of 70P/23I/5C/2M were lowered compared with those of 70P/25I/5C. Dynamics analysis indicated that the addition of modified cassava dregs–MHSH hybrids increased the activation energy of composites. Based on the experimental and analyses data, especially the morphological characterization of char residue analysis, it illustrated that modified cassava dregs–MHSH hybrids have a reinforcement and flame-retardant effect. The combusted residue of the incorporated modified cassava dregs–MHSH hybrids could support the three-dimensional charred layer formed by the combustion products of the IFR and the PBS. Thus, the more stable three-dimensional charred layer could not only effectively reduce thermal conductivity of composites but also hinder the propagation of heat into the interior substrate, thereby improving the flame-retardant properties of the WPC. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48490.     

An efficient approach to improving fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene composites via incorporating organo‐modified sepiolite

In this work, an efficient approach to improving the fire retardancy and smoke suppression for intumescent flame‐retardant polypropylene (PP) composites is developed via incorporating functionalized sepiolite (organo‐modified sepiolite [ONSep]). The PP composites with different amounts of intumescent flame retardants and ONSep were prepared by melt compounding. The morphology, thermal behavior, fire retardancy, smoke suppression, and mechanical property of flame‐retardant PP composites were studied. The results indicate an appropriate amount of ONSep in the flame‐retardant PP composites can increase thermal degradation temperature and char formation as well as a reduction of the peak heat release rate and total heat release; moreover, the addition of ONSep significantly decreases the CO production, total smoke production, smoke production rate, and smoke temperature. Simultaneously, the impact strength of intumescent flame‐retardant PP composite is also maintained by introducing an appropriate amount of ONSep as compared with that without ONSep.