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1.
A novel bio-based carbon forming agent (Mg@PA-CS) containing P and N elements was were synthesized using the complexation characteristics of chitosan (CS) and phytate (PA). The flame retardant behavior of poly(lactic acid) (PLA)/Mg@PA-CS/APP composites (addition of 20 wt% of different ratios of Mg@PA-CS and APP to polylactic acid composites) were investigated by the limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimetry test (CCT), and thermogravimetric analysis (TGA). Due to the biphasic flame retardant and synergistic effect, since the 20 wt% flame retardant system (Mg@PA-CS:APP = 1:2), PLA composites passed the UL-94 test V-0 rating, reached 34% LOI value. The peak heat release rate (PHRR) and total heat release rate (THR) were reduced to 1/2 of the pure PLA, char residue could be as high as 11.49% at 800°C. Moreover, the flame-retardant mechanism of PLA composites during thermal decomposition was analyzed using a scanning electron microscope (SEM) and the coupling techniques of TGA linked with FT-IR (TG-FTIR).  相似文献   

2.
Ammonium polyphosphate (APP) was modified using a new method, where the resulting modified APP (MAPP) was obtained by mixing APP with unsaturated polyester resin (UPR). MAPP was more effective in improving the flame retardancy of UPR than APP which was due to the improved dispersion of MAPP in UPR composite. Then, the UPR composites were prepared based on dimethyl methylphosphonate, MAPP, montmorillonite, and zinc borate. Finally, the flame-retardant and mechanical properties of the UPR composites were analyzed using the limited oxygen index (LOI), thermogravimetric analysis, UL-94 vertical burning test, scanning electron microscopy, cone calorimetry, mechanical tests, and viscosity measurements. The LOI and UL-94 tests showed that the flame-retardant properties clearly improved with the addition of fillers in the UPR composites compared to pristine UPR. The synergistic effect of Si- and P-containing flame retardants in this composite resulted in the LOI value increasing from 18.9 to 31.3% and achieved the UL-94 V-0 rating. Moreover, the heat release rate was lower than the pristine UPR. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47180.  相似文献   

3.
Vinyl polysiloxane microencapsulated ammonium polyphosphate (MAPP) was prepared by a sol-gel method using vinyltrimethoxysilane as a precursor to improve its thermal stability and hydrophobicity. The MAPP was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and thermogravimetric analyzer (TGA). The results showed that ammonium polyphosphate (APP) was successfully coated with vinyl polysiloxane. MAPP and pentaerythritol (PER) were used together to improve the flame retardancy of polypropylene (PP). The flame retardant properties of PP composites were investigated by limiting oxygen index (LOI), UL-94 test, TGA and SEM. When the MAPP was added as a flame retardant, with PER as a char forming agent, the LOI of PP/MAPP/PER composites was 33.1%, and it reached the UL-94 V-0 level. The results also demonstrated that the flame retardant properties of PP/MAPP/PER composites were better than those of PP/APP/PER composites at the same loading. Moreover, the addition of flame retardant and carbon forming agent could promote the crystallization behavior of PP.  相似文献   

4.
The epoxy resin was mixed with ammonium polyphosphate (APP) and hyperbranched silicon-containing polymers (HBP-B2). The cured composites were investigated by thermogravimetric analysis, Underwriters Laboratory standard for the flammability properties under vertical burning (UL-94V), and limited oxygen index (LOI) test methods. The LOI of 43.5 and could be obtained at the weight ratio of 70:25:5 for the epoxy resin:APP:HBP-B2, Sample A25B5, and the LOI was higher than that of the composite with 30 wt % APP only, Sample A30B0, of which the LOI was 34.5. It suggested that the HBP-B2 could cooperate with the epoxy/APP composite to form a more effective protection layer during combustion, which resulted in a higher second-stage thermal degradation temperature. During the UL-94V test, the flame was extinguished immediately once the burner was removed. Furthermore, the tensile and impact strength of the epoxy/APP composite could also be improved by using HBP-B2 compound as the toughening agent. The composite containing 20% of APP and 10% of HBP-B2, Sample A20B10, still had excellent flame retardant properties with a V-0 rating. Moreover, the tensile strength and impact strength of that composite got 19 and 25% increases compared with the Sample A30B0, which contained 30% of APP only. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48857.  相似文献   

5.
宋剑峰  李曼  梁小良  粟海锋 《化工进展》2018,37(11):4412-4418
以聚磷酸铵(APP)、季戊四醇(PER)和三聚氰胺(MEL)复配的膨胀型阻燃体系(IFR)为主要阻燃剂,表面改性后的赤泥(Ti-MRM)作为协效剂阻燃聚乙烯(PE),采用熔融共混法制备PE基阻燃复合材料(PE/IFR-Ti-MRM)。通过热重分析仪(TGA)、垂直燃烧仪(UL-94)、极限氧指数测定仪(LOI)及扫描电镜(SEM)等对其热氧稳定性、燃烧等级、阻燃性能和残炭形貌进行了表征与分析。结果表明:加入改性赤泥的PE/IFR-Ti-MRM复合材料形成的炭层更加致密和连续,当最优配比时,复合材料的极限氧指数达到32.2,燃烧等级达到V-0级;而PE/IFR阻燃复合材料的极限氧指数只能达到27.5,燃烧等级为V-2级。  相似文献   

6.
A core shell material consisting of ammonium polyphosphate as core and 4,4-oxydianiline-formaldehyde resin as shell was prepared through a situ microencapsulation technology. The monomer of the polyurethane (PU) was modified to form bridged polysesquisiloxane. The purpose of modification is to improve the thermal stability of polyurethane matrix through the formation of networks. The degree of the networks was evaluated by solid state 29Si-nuclear magnetic resonance. The structure and hydrophobic property of microencapsulated flame retardant were characterized using X-ray photoelectron spectroscopy and water solubility. The results indicated that the microencapsulation of APP with 4,4′-oxydianiline-formaldehyde resin (OF resin) resulted in improved hydrophobicity. The thermal properties of final flame retardant were systematically analyzed through thermogravimetric analysis. Limiting oxygen index and UL-94 test were used to classfied the flame retardant properties of varying the composition of APP and OFAPP in silanol-terminated polyurethane composites. Pure PU exhibited an LOI of 17 % and failed the UL-94 test. The LOI values of the 40 % OFAPP-added composites can reach 41 % and pass V-0 level. The results revealed that the microcapsulation of commercial flame retardant can improve the flame retardance of the composites.  相似文献   

7.
In this study, 4,4′-Diaminodiphenyl methane (DDM) was exploited as hardener for diglycidyl ether of daidzein (DGED) and epoxy resin mixture (E-D). The composites were produced by blending with different contents of ammonium polyphosphate (APP) and expandable graphite (EG) into E-D resin, named E-D/A-E composites. Firstly, E-D/A-E blends were analyzed by Fourier transform infrared spectroscopy and DSC to evaluate their curing behavior. The TGA was performed on the E-D/A-E composites to analyze their thermal stability, and the thermal properties of the composites were enhanced by adding APP-EG (A-E) flame retardants. The mechanical properties and the fractured surfaces of the E-D/A-E composites were studied by tensile, impact tests and scanning electron microscopy. Finally, through torch burning test, limiting oxygen index (LOI), vertical burning (UL-94) and micro-calorimetry tests, the influence of A-E flame retardants contents on flammability of composites were evaluated. The results showed that the UL-94 V-0 rating was obtained for the E-D/A-E composites and the composites exhibited a self-extinguishing phenomenon. When A-E flame retardants content reached 9.1 wt%, the LOI value reached 34.5%, and total heat release (Total HR) was reduced by 20.2% compared with E-D/A-E 1.  相似文献   

8.
A phosphorus-nitrogen flame retardant (PN) was synthesized by using cytosine and diphenylphosphinic chloride. The flame retardancy and thermal stability of polylactic acid (PLA)/PN composites were investigated by the UL-94 vertical burning test, limited oxygen index (LOI), cone calorimeter test, and thermogravimetric analysis. The PN performs efficiently on improving the flame retardancy of PLA. The PLA composite achieves the UL-94 V-0 rating and its LOI increases to 30.4 vol% by adding 0.5 wt% PN. The flame retardant mechanism analysis showed that PN catalyzes the degradation of PLA to improve the flame retardancy by melting-away mode. Meanwhile PN reduces the release of flammable gasses during thermal degradation of PLA by promoting the transesterification of PLA, which is helpful for extinguishing flame. Moreover, triglycidyl isocyanurate (TGIC) was used as a micro-crosslinking agent to reduce the loss of mechanical properties of PLA/PN composites caused by degradation. Adding 0.1 wt% TGIC and 1.0 wt% PN into PLA, the tensile strength and elongation at break of PLA/PN are increased to the same level as that of PLA. Therefore, PLA with excellent comprehensive performance can be obtained.  相似文献   

9.
Microencapsulated ammonium polyphosphate (GMFAPP) is prepared by in situ polymerization method with a shell of poly(ethylene glycol) modified melamine-formaldehyde resin. Due to the presence of shell, GMFAPP shows less size, higher water resistance and flame retardancy in polypropylene (PP) compared with ammonium polyphosphate (APP). The flame retardant action of GMFAPP and APP in PP are studied using LOI, UL-94 and cone calorimeter, and their thermal stability is evaluated by thermogravimetric apparatus. The limiting oxygen index (LOI) value of the PP/GMFAPP at the same loading is higher than the value of PP/APP. UL-94 ratings of PP/GMFAPP can reach V-0 at 30 wt% loading. The water resistant properties of the PP composites are studied, and the results of the composites containing with APP and GMFAPP are compared. The cone results put forward that GMFAPP is an effective flame retardant in PP compared with APP. Moreover, the thermal oxidative behavior of GMFAPP is evaluated by dynamic FTIR to study its flame retardant mechanism in PP.  相似文献   

10.
ABSTRACT

Despite extraordinary mechanical properties and excellent biodegradability, poly (lactic acid) (PLA) still suffers from a highly inherent flammability, restricting its applications in the electric and automobile fields. Although a wide range of flame retardants have been developed to reduce the flammability, they normally compromise the mechanical strength of PLA. In this study, a series of composites based on PLA, have been prepared by melt-blending with intumescent flame retardants (IFRs). The morphology, thermal stability and burning behaviour of the composites were investigated using a scanning electron microscope–energy dispersive spectrometer (SEM–EDS), thermogravimetric analysis (TGA), the limiting oxygen index (LOI), vertical burning (UL-94) and the cone calorimeter test (CCT). The LOI value reached 38.5% and UL-94 could pass V-0 for the PLA/IFR composite containing only 12 wt-% IFR. The dispersion of IFR in PLA was observed using SEM–EDS. A significant improvement in fire retardant performance was observed for the PLA/IFR composite from the CCT (reducing the heat release rate and the total heat release). More importantly, compared to pure PLA, the addition of IFR did not seriously deteriorate the mechanical properties of the material.  相似文献   

11.
Microencapsulated ammonium polyphosphate (VAPP) with poly(vinyl alcohol)- melamine-formaldehyde (VMF) shell was introduced in ethylene vinyl acetate copolymer (EVA) to improve its flame retardancy. Due to the presence of VMF shell, VAPP shows better compatibility, flame retardancy and water resistance compared with ammonium polyphosphate (APP) in EVA. The flammability of EVA and its flame-retarded composites was studied by LOI, UL-94 and cone calorimeter. The composite containing 40 wt% VAPP can pass V-0 in UL-94 test, and hot water treatment shows few effects on its LOI value and UL-94 rating. The cone results indicated that the use of VAPP in EVA can significantly decrease heat release rate and total heat release compared with APP. To understand the mechanism of action of VAPP, dynamic FTIR experiments were carried out on EVA and EVA/VAPP composites. Based on above studies, the flame retardant mechanism of VAPP in EVA composite is discussed.  相似文献   

12.
A novel intumescent flame retardant (IFR) composed of ammonium polyphosphate (APP), benzoxazine containing trialkoxysilane (BA-a-Si) and melamine (ME), is compounded with different specifications of MoS2 as synergist to flame retard polyformaldehyde (POM). The flame retardancy and mechanism of the composites are analyzed by limiting oxygen index (LOI), vertical combustion (UL-94) and cone calorimeter. At the same time, the mechanical properties and lubricating properties are tested by electromechanical testing machine and wear testing machine. The experimental results show that MoS2 has a good synergistic effect with IFR, and the smaller the average particle size of MoS2 is, it seems to be more beneficial to improve the flame retardancy of POM composites. Only a small amount of MoS2 (0.8 wt%) is needed to synergize with IFR, the flame retardant POM composite (FR-POM) can achieve UL-94 (3.2 mm) V-0 rating, LOI of 62.5%, and heat release rate reduction of 25.3%, total smoke release decreased by 29.5%. In addition, from the mechanical properties analysis, it is found that the microscale MoS2(M2) can better improve the bending and tensile properties of the FR-POM composites, while the nanoscale MoS2(N80) is more helpful to improve the lubricating properties.  相似文献   

13.
De-Yi Wang 《Polymer》2011,52(2):233-2967
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.  相似文献   

14.
In this paper, ammonium polyphosphate(APP)/expandable graphite(EG)/thermoplastic polyurethane (TPU) composites were prepared by microlayer coextrusion technology, APP and EG fillers had good synergistic flame retardancy and excellent dispersion in TPU matrix, which greatly improved the flame retardancy and mechanical properties of multilayer composites. The dispersion of APP and EG in TPU was characterized by using SEM, the flame retardancy of composites was characterized by using UL94 and LOI, the thermal stability of composites was characterized by using TGA and DTG, and tensile test was used to characterized the mechanical properties of composites. SEM showed that the microlayer coextrusion technology significantly improved the dispersion of APP and EG in TPU. As showed by the experimental results, the vertical combustion level of ordinary blended composites reached V-2 after adding only one kind of filler either APP or EG, and the vertical combustion level of ordinary blended composites reached V-0 with APP and EG applied together, while the vertical combustion level of microlayer coextruded composites all reached V-0 when the total addition of APP and EG was 15%. In particular, the LOI value of microlayer coextruded composites was 30.9%, while the LOI value of ordinary blended composites only was 27.9% when APP: EG = 1: 1. At this time, the flame retardancy level of APP/EG/TPU composites was the best. In addition, the thermal stability and mechanical properties of microlayer coextruded composites were far superior to ordinary blended composites. In conclusion, the synergistic flame retardancy of APP and EG fillers and the dispersion of APP and EG fillers in TPU matrix played a significant role in enhancing flame retardancy and mechanical properties.  相似文献   

15.
彭建文  彭中朝  宋强  李端生  黄若森  唐刚 《塑料》2020,49(2):32-35,39
采用简单方法合成苯基次膦酸铈(CeP),并将其作为阻燃剂加入聚乳酸(PLA)中,通过熔融共混技术制备聚乳酸/苯基次膦酸铈(PLA/CeP)复合材料。通过热重(TG)、极限氧指数(LOI)、UL-94垂直燃烧(UL-94)、微型量热(MCC)研究复合材料的热稳定性、阻燃性能和燃烧性能。通过阻燃测试发现,CeP能够提高复合材料阻燃性能,PLA/CeP20极限氧指数能达到24.3%并通过UL-94 V-2级别。热重分析的结果表明,CeP显著提高了PLA/CeP复合材料初始分解温度和成炭率。MCC测试结果表明,CeP能明显降低PLA/CeP复合材料火灾危险性。PLA/CeP20热释放速率峰值(PHRR)和总热释放(THR)分别为397 W/g和13.6 kJ/g,与纯聚乳酸相比,分别下降了13.9%和28.0%。因此,苯基次磷酸铈对聚乳酸具有良好的阻燃效果。  相似文献   

16.
Polylactic acid (PLA) is regarded as one of the most promising bioplastics. However, its inherent high flammability of PLA seriously limits its application in the emerging fields. Although the traditional phosphate flame retardants showed excellent flame retardant efficiency in PLA, they often failed to meet the processing requirements of PLA and the thermal stability of PLA composites was decreased after their addition. Herein, an organophosphate flame retardant pentaerythritol bis(phenyl phosphonate) (PBPP) with high thermal stability and phosphorus content was synthesized by the nucleophilic substitution reaction in our laboratory. The introduction of PBPP simultaneously improved the flame retardancy, thermostability and crystallization properties of PLA. Only 3 wt% PBPP endowed PLA composites with UL-94 V-0 grade and higher LOI of 28.3% due to its excellent gas phase effect. Moreover, the crystallinity of PLA/PBPP4 was enhanced from 14.2% of PLA to 32.2% with the improvement of 127%. Because of the similar structure and good compatibility between organophosphate flame retardant and PLA matrix, flame retardant PLA/PBPP maintained almost the same strength as neat PLA. This study provided a novel way for the preparation of a high-performance flame retardant PLA composites with excellent comprehensive properties and it was important to expand the application value of multifunctional PLA materials.  相似文献   

17.
Silica (SiO2) nanohybrid expandable graphite (nEG) particles fabricated through one-step method are used as an efficient flame retardant for polypropylene (PP)/polyamide 6 (PA6) blends. The effect of nEG on the flammability, thermal stability, crystallization behaviors, and mechanical properties of PP/PA6 composites is investigated by using limit oxygen index (LOI), UL-94 test, cone calorimeter test (CCT), thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared, scanning electron microscopy, and mechanical tests. Compared with pure expandable graphite (EG), nEG improves the flame retardancy of composites. The results of LOI show that LOI of PP/PA6/nEG10 and PP/PA6/nEG15 composites are 26.0% and 27.2%, respectively. But the LOI values of PP/PA6/EG10 and PP/PA6/EG15 composites are 25.7% and 26.9%, respectively. The UL-94 test results show that PP/PA6/nEG10 composites reach V-1 level when the nEG content is only 10%. However, the PP/PA6 composites with 10% EG does not pass the UL-94 test. In addition, PP/PA6 composites with 15% nEG can reach V-0 level. The CCT results further show that nEG has a higher flame-retardant efficiency than pure EG for PP/PA6 blends. The thermal stability of PP/PA6/nEG composites is better than that of PP/PA6/EG composites. The mechanical property tests indicate that nEG is more conducive to maintain the tensile and impact strengths of PP/PA6 blends than EG due to the enhanced compatibility and interfacial adhesion.  相似文献   

18.
陈志杰  郑玉婴  邱洪峰 《化工学报》2015,66(3):1221-1227
以热塑性淀粉(TPS)为成炭剂与聚磷酸铵(APP)、可膨胀石墨(EG)复配组成膨胀型阻燃剂,通过熔融密炼、开炼塑化、硫化发泡制备了热塑性淀粉/乙烯-醋酸乙烯酯共聚物(TPS/EVA)泡沫复合材料,探讨了TPS用量对泡沫复合材料阻燃性能、力学性能的影响。结果表明,TPS的加入显著提高了TPS/EVA泡沫复合材料阻燃性能,可起到良好的成炭作用;TPS/EVA泡沫复合材料的拉伸强度、断裂伸长率以及撕裂强度随着TPS用量的增加呈现先增大后减小的趋势,相对密度则是小幅度上升。当TPS用量为6%时,TPS/EVA泡沫复合材料综合性能最好,其LOI可达26.5%且UL-94为V-0级,拉伸强度、断裂伸长率、撕裂强度以及相对密度可达2.395 MPa、177.48%、10.59 N·mm-1、0.21452。  相似文献   

19.
Poly(lactic acid) (PLA) nanocomposite with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) intercalated calcium montmorillonite (Ca-MMT) nanocompound was prepared, and the properties were compared with those of PLA/Ca-MMT, PLA/DOPO, and PLA/DOPO+Ca-MMT nanocomposites (where DOPO+Ca-MMT indicates a physical mixture of DOPO and Ca-MMT). The structures and properties of the four PLA nanocomposites were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry, thermogravimetric analysis, limiting oxygen index (LOI) testing, UL-94 vertical testing, and cone calorimetry measurements. The XRD and TEM tests showed that the DOPO–Ca-MMT nanocompound existed in both intercalated and exfoliated montmorillonite morphologies in the PLA matrix, a better dispersion state than the Ca-MMT added alone and DOPO+Ca-MMT in PLA; this benefited improvements in the crystallinity, thermal stability, and flame retardancy for the PLA/DOPO–Ca-MMT nanocomposite, as seen in the higher degree of crystallinity, higher LOI values, and lower peak heat-release rate. A loading of only 5 wt % DOPO–Ca-MMT increased the LOI value of PLA from 20.0 to 28.3% and made the PLA pass the UL-94 vertical test V-0 rating at a 3.2 mm thickness. The nanocomposites based on DOPO–Ca-MMT could be used as very efficient systems for flame-retardant PLA. The PLA/DOPO–Ca-MMT also had better tensile mechanical properties than the pure PLA and PLA/DOPO+Ca-MMT. The annealing specimens of the four nanocomposites were also characterized to study the relationship between the PLA crystallization and flame retardancy or mechanical properties. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 46982.  相似文献   

20.
为了提高苯乙烯一丁二烯一丙烯睛(ABS)/聚磷酸铵(APP)/聚对苯二甲酞乙二胺(PETA)膨胀阻燃体系的阻燃性能,将硼酸锌(ZB)、红磷(RP)添加到ABS/ APP/ PETA膨胀阻燃体系中。采用极限氧指数法、垂直燃烧法、热失重、扫描电镜探讨了不同含量协效剂ZB,RP对不同比例ABS/APP/PETA阻燃体系的协效阻燃效应。结果表明,加人协效剂使ABS/APP/PETA体系的阻燃性能得到显著提高;将2.5份(质量份,下同)ZB和4份RP加人到ABS/APP/PETA( 70/22. 5/7. 5)体系,体系的极限氧指数由未加协效剂的30%提高到41%,UL-94测试也达到V-0级;ZB提高了ABS/APP/PETA体系热稳定性和成炭率,RP能极大地促进成炭;加人ZB和RP ,阻燃体系燃烧表面能够形成更多膨胀、致密的炭层。  相似文献   

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