杨木胶合板阻燃性能研究

通过热释放速率(HRR)、总热释放量(THR)、有效燃烧热(EHC)、CO产率、CO2产率以及烟释放总量等指标,研究了杨木胶合板的阻燃性能。实验结果表明:磷酸氢镁和二氧化锆阻燃剂单独使用时,都能够在杨木胶合板燃烧过程中降低热释放速率、总热释放量、有效燃烧热、CO2产率以及烟释放总量,增大CO产生速率,但阻燃效果不理想;而磷酸氢镁与纳米二氧化锆复合阻燃剂,可以在杨木胶合板燃烧过程中产生协同效应,并且使用此复合阻燃剂的杨木胶合板在点燃190 s后即停止燃烧,其阻燃效果最佳。     

苯基次膦酸铝用于玻纤增强PBT的无卤阻燃

采用一种新型次膦酸盐阻燃剂苯基次膦酸铝复配三聚氰胺焦磷酸盐对玻纤增强聚对苯二甲酸丁二醇酯(PBT)进行无卤阻燃改性。通过热重分析研究了阻燃剂的加入对体系热分解过程的影响,通过氧指数、UL-94垂直燃烧及锥形量热测试研究了阻燃体系的阻燃性能。研究表明,苯基次膦酸铝与三聚氰胺焦磷酸盐复配比例为1∶1时阻燃效果最好,材料氧指数达到26.0%,通过UL-94 V-0级,同时样品热释放速率HRR降低至146 kW/m2,热重分析表明,两种阻燃剂之间通过化学反应促进了材料的提前分解,有利于在材料表面形成保护性炭层,从而提高了材料的阻燃性能。     

聚硼硅氧烷与有机磷酸酯阻燃剂复配协同阻燃PC

将聚硼硅氧烷(PB)阻燃剂分别与三种有机磷酸酯(OPP)阻燃剂进行复配,并将此复合阻燃剂添加到聚碳酸酯(PC)中制备了阻燃PC材料(FR-PC)。采用极限氧指数(LOI)和锥形量热分析研究了PB对OPP/PC体系的协效阻燃作用。结果表明,在阻燃剂总量为5%(质量分数)时,添加占阻燃剂总量25%(质量分数)以上的PB可以提高OPP/PC体系的LOI。PB阻燃剂具有促进成炭的作用,可使OPP/PC复合体系在燃烧过程中释放的烟、热以及CO有不同程度的降低,燃烧过程趋于平缓,尤其使体系的烟释放量显著降低,三种OPP/PC阻燃体系的总烟释放量分别下降30%~50%,大大降低了火灾的危害性。添加适量PB能够提高OPP/PC体系的拉伸强度、弯曲强度及维卡软化点温度,并且使PC复合阻燃材料的透光率有所提高,保持了PC良好的透明性。     

聚硼硅氧烷与有机磷酸酯阻燃剂复配协同阻燃聚碳酸酯

将聚硼硅氧烷(PB)阻燃剂分别与三种有机磷酸酯(OPP)阻燃剂进行复配, 并将此复合阻燃剂添加到聚碳酸酯(PC)中制备了阻燃PC材料(FR-PC)。采用极限氧指数(LOI)和锥形量热分析研究了PB对OPP/PC体系的协同阻燃作用。结果表明: 阻燃剂总质量分数为5%时, 添加质量分数1.25%以上的PB可以提高OPP/PC体系的LOI; PB阻燃剂具有促进成炭的作用, 可使OPP/PC复合体系在燃烧过程中释放的烟、热以及CO有不同程度的降低, 燃烧过程趋于平缓, 尤其使体系的烟释放量显著降低, 三种OPP/PC阻燃体系的总烟释放量下降31.8%~51.0%, 大大降低了火灾的危害性; 添加适量PB能够提高OPP/PC体系的拉伸强度、弯曲强度及维卡软化点温度, 并且使PC复合阻燃材料的透光率有所提高, 保持了PC良好的透明性。     

新型无卤膨胀阻燃聚丙烯的制备及阻燃性能

利用有机杂环磷酸酯1, 2, 3-三(5, 5-二甲基-1, 3-二氧杂环己内磷酸酯基)苯(FR)、聚磷酸铵(APP)和三聚氰胺(MEL)制备新型无卤三源膨胀阻燃聚丙烯(IFR/PP)材料, 通过极限氧指数(LOI)、水平燃烧(UL-94)、热重分析法(TGA)、锥形量热(cone)等方法研究了IFR对聚丙烯阻燃性能影响。结果表明: 当IFR总添加质量分数为30%(FR∶APP∶MEL质量比为4∶8∶3), 阻燃IFR/PP的LOI 达到36.2%, 其热释放速率峰值(pk-HRR)、热释放速率平均值(av-HRR)、有效燃烧热平均值(av-EHC)、比消光面积平均值(av-SEA)、质量损失速率平均值(av-MLR)及一氧化碳释放率平均值(av-CO)相对未阻燃PP分别降低75.9%、71.7%、76.4%、74.6%、58.3%和50.0%, 300 s时CO释放量接近0, 呈现出良好的阻燃、抑烟和抑毒性能; SEM研究表明, IFR催化PP在燃烧初期形成了致密、坚硬的优质炭层。     

六(γ-氨丙基硅烷三醇)环三磷腈的制备及其在膨胀阻燃聚丙烯中的应用

以六氯环三磷腈、对羟基苯甲醛及γ-氨丙基硅烷三醇(KH553)为反应原料,合成了具有席夫碱结构的有机硅型成炭剂六(γ-氨丙基硅烷三醇)环三磷腈(HKHPCP)。以HKHPCP与聚磷酸铵(APP)的复配物为抗熔滴剂,以N-烷氧基受阻胺(NOR116)为阻燃协效剂,通过熔融共混技术制备了膨胀阻燃聚丙烯(PP)基复合材料(APP-HKHPCP-NOR116/PP)。利用FTIR、核磁共振(1 H和31P NMR)对HKHPCP的化学结构进行了表征。采用热失重、极限氧指数、垂直燃烧、锥形量热、拉曼光谱和SEM研究了阻燃体系的热降解行为、阻燃性能及炭层的石墨化程度和致密性。HKHPCP的热失重结果表明,其在氧气氛围下的初始分解温度为300.2℃,1 000℃时残余率为34.8%。当添加总量为30wt%的阻燃剂时,APP-HKHPCP-NOR116/PP复合材料的极限氧指数(LOI)达到43%,且能通过UL-94V-0级,其热释放速率(HRR)、总热释放速率(THR)及烟释放速率(SPR)、总烟释放量(TSP)相比于纯PP分别降低了75.0%、50.5%和88.0%、80.8%,表现出显著的隔热、抑烟性能。APPHKHPCP-NOR116/PP复合材料燃烧后形成了高石墨化、致密的炭层。     

三聚氰胺聚磷酸盐/笼状季戊四醇磷酸酯协效阻燃聚丙烯/稻壳复合材料的研究

利用三聚氰胺聚磷酸盐(MPP)和笼状季戊四醇磷酸酯(PEPA)的阻燃协效作用,复配成膨胀型阻燃剂(IFR)对聚丙烯(PP)/稻壳(RH)复合材料进行阻燃。研究了MPP与PEPA复配比例对PP/RH复合材料阻燃性能的影响。采用垂直燃烧(UL-94)和极限氧指数(LOI)研究了阻燃PP/RH复合材料的阻燃性能,采用热重分析研究阻燃PP/RH复合材料的热分解过程,采用扫描电镜(SEM)观察阻燃PP/RH复合材料燃烧后炭层的形貌。结果表明:当MPP/PEPA总用量为20%(wt%,质量分数),PEPA和MPP的质量分数比为1∶4时,阻燃PP/RH复合材料的LOI值为29.7%,垂直燃烧UL-94通过V-0级,PP/RH复合材料的拉伸强度和弯曲强度分别增加了42.3%和53.6%。热重结果表明:MPP/PEPA复配能够延缓PP/RH体系中PP的分解,并提高了材料的成炭性,使PP/RH复合材料800℃下的残炭率由16.3%提高到了30.3%,残炭率升高了14.0%。通过SEM观察得到:两者复配使PP/RH复合材料燃烧后形成了致密均匀的多孔炭层,从而提高了PP/RH复合材料的阻燃性能。     

纳米SiO2和MgAl-SDBS-LDHs在聚丙烯中的协同分散及协效阻燃性能研究

以有机改性纳米SiO2和MgAl-SDBS-LDH为填料,采用熔融共混法制备PP/MgAl-SDBS-LDHs、PP/MgAl-SDBS-LDHs/SiO2复合材料。采用XRD、TGA、氧指数仪、水平垂直燃烧仪和锥形量热仪等方法,探讨纳米SiO2、MgAl-SDBS-LDHs在聚丙烯中的协同分散及协效阻燃性能。结果表明:相比PP/MgAl-SDBS-LDHs,PP/MgAl-SDBS-LDHs/SiO2复合材料体系的分散性得到明显改善。PP/5%MgAl-SDBS-LDHs/10%SiO2复合材料的初始分解温度较纯PP升高62℃,残留量达到11.18%。样品达到UL-94水平燃烧测试标准,极限氧指数(LOI)提高3.8,平均质量损失速率(AMLR)下降1.8g/(m2·s),生烟总量(TSP)增加4.7m2,热释放速率峰值(PHRR)下降41%。有机改性纳米SiO2改善了MgAl-SDBS-LDHs在聚丙烯中的分散性并提高了复合材料的阻燃性能。     

β-环糊精-聚磷酸铵对黄麻/聚丙烯复合材料阻燃性能的影响

将黄麻纤维和聚丙烯纤维（PP）通过梳理、铺网和针刺的方式形成黄麻/PP复合材料毡,采用表面撒粉工艺,将阻燃剂β-环糊精（β-CD）、β-CD与聚磷酸铵（APP）复配热压后在黄麻/PP复合材料表面形成阻燃层,采用FTIR、极限氧指数测试仪、水平燃烧测试仪、锥形量热测试仪、热重分析测试仪、SEM及万能试验机等检测黄麻/PP复合材料阻燃性能、力学性能、成炭性能及样品表面微观形貌。结果表明:β-CD与APP复配后在黄麻/PP复合材料表面热压成膜可以显著提高复合材料的阻燃性能和热稳定性。当β-CD-APP复配阻燃剂质量分数为20wt%、β-CD与APP的质量比为1∶2时,黄麻/PP复合材料水平燃烧58 s后自熄,极限氧指数（LOI）值达到26.6%,根据日本JISD 1201—77标准,属于第三难燃等级材料,此时热释放速率和有效燃烧热值最小,700℃时的残炭量增加了11.68%。力学性能测试表明,在黄麻/PP复合材料表面增加阻燃层后,弯曲强度增加而拉伸强度不受影响。      

分子筛和SiO_2对含三嗪大分子膨胀阻燃聚丙烯体系的阻燃协效性

研究了两种化合物4A分子筛(Zeolite4A)和二氧化硅(SiO2)对聚丙烯膨胀阻燃新体系聚丙烯/聚磷酸铵/三嗪系成炭剂(PP/APP/CFA)阻燃性的影响,通过垂直燃烧、氧指数、热重分析、锥形量热仪和扫描电镜等技术研究表明,这两种含硅物质均能有效提高聚丙烯体系的阻燃性。膨胀阻燃剂能有效降低聚丙烯材料的热释放速率和烟释放速率,特别是,这两种含硅物质能明显降低聚丙烯体系第二个燃烧过程的热释放速率和烟释放速率。     

Dispersion,thermal and mechanical properties of polypropylene/magnesium hydroxide nanocomposites compatibilized by SEBS-g-MA

Isotactic polypropylene (PP)/nano-magnesium hydroxide (nano-MH) composites with 10 wt.% maleic anhydride grafted styrene–ethylene-butylene–styrene tri-block copolymer (SEBS-g-MA) as a compatilizer were prepared by melt extrusion compounding and injection molding. The effects of SEBS-g-MA on dispersion of nano-MHs in PP matrix and interfacial adhesion were studied in order to prepare highly filled PP/MH nanocomposites. The results showed that SEBS-g-MA improved both dispersion of nano-MHs and interfacial adhesion in PP/MH nanocomposites with up to 40 wt.% nano-MHs. The elastic moduli of PP/SEBS-g-MA /MH nanocomposites increased marginally and tensile yield strengths were almost invariant with nano-MH loading. Significant impact toughening of these ternary nanocomposites was, however, achieved due to the cavitation of SEBS-g-MA/MH particles and expansion of voids as well as plastic deformation of the PP matrix.     

表面改性对聚丙烯/纳米氢氧化镁复合材料性能的影响

研究了表面处理剂(钛酸酯和硅烷偶联剂)对聚丙烯/纳米氢氧化镁(MH)阻燃复合材料性能的影响。通过高压毛细管流变仪、LO I、力学测试、DSC和SEM对PP/纳米MH复合体系的结构与性能进行了研究。结果表明,所选偶联剂能有效地降低复合体系的表观黏度,改善体系的流动性。未改性的纳米MH对PP基体有异相成核作用;而表面改性剂能削弱填料对基体的异相成核作用。改性后的纳米MH粒子以独立形式均匀分散在基体中,PP与纳米MH界面的粘接力得到了加强,复合材料的拉伸性能和冲击强度有较大幅度的提高,阻燃性能也得到了改善。     

Fracture behavior of polypropylene/clay nanocomposites

Polypropylene (PP)/clay nanocomposites have been prepared via a reactive compounding approach with an epoxy based masterbatch. Compared with PP and common PP/organoclay nanocomposites, the PP/clay nanocomposites based on epoxy/clay masterbatch have higher impact strength. The phenomenon can be attributed to the epoxy phase dispersed uniformly in the PP matrix, which may act as impact energy absorber and helps to form a large damage zone, thus a higher impact strength value is achieved.     

芳纶浆粕对膨胀阻燃聚丙烯性能影响

采用芳纶浆粕(PPTA-pulp)对膨胀阻燃聚丙烯(PP)进行增强改性,通过一步共混法制备了PPTA-pulp-膨胀型阻燃剂(IFR)/PP阻燃复合材料,考察了PPTA-pulp用量对PPTA-pulp-IFR/PP复合材料的力学性能、阻燃性能及热稳定性能的影响。结果表明,当硅烷偶联剂KH-550处理的PPTA-pulp质量比为5%时,膨胀阻燃复合材料的力学性能达到最佳: 拉伸强度40.0 MPa,冲击强度56.9 J·m^-1,极限氧指数LOI 28%,垂直燃烧等级达到UL-94 V-0级。复合材料的热稳定性能提高,炭残余量增加。SEM观察表明,PPTA-pulp经KH-550处理后,浆粕纤维与基体树脂的结合性较好。     

硅丙乳液包覆Mg(OH)2核壳结构纳米粒子的制备与表征

为有效提高Mg(OH)_2纳米粒子在硅丙乳液中的相容性与分散稳定性,在油酸修饰Mg(OH)_2纳米粒子的基础上,以甲基丙烯酸甲酯、丙烯酸丁酯、丙烯酸与乙烯基三乙氧基硅烷为共聚单体,通过乳液聚合法制备出具有核壳结构的硅丙乳液包覆Mg(OH)_2复合材料。利用傅里叶变换红外光谱仪(FTIR)、X射线衍射仪(XRD)、透射电子显微镜(TEM)等测试手段对样品结构、形貌进行了表征。通过燃烧实验,研究了硅丙乳液包覆Mg(OH)_2纳米粒子对水性防火涂料阻燃性能的影响。结果表明,油酸通过酯化作用修饰在Mg(OH)_2纳米粒子表面,借助油酸分子中双键结构,丙烯酸类混合单体在纳米Mg(OH)_2表面完成聚合过程,形成以Mg(OH)_2纳米粒子为核、硅丙乳液为壳的复合材料。XRD与热分析表明经硅丙乳液包覆的纳米Mg(OH)_2晶体结构与热稳定性能未受影响。此外,掺杂0.1%(质量分数)的硅丙乳液包覆Mg(OH)_2可使水性防火涂料阻燃时间延长至113 min,较未掺杂水性涂料阻燃时间(91min)提高约23%。     

Effect of Amino alcohol functionalized polyethylene as compatibilizer for LDPE/EVA/clay/flame-retardant nanocomposites

The synergistic effect of organo-modified montmorillonite (Nanomer I28E and Cloisite 20A) and metal hydroxides (magnesium hydroxide MH and alumina trihydrate ATH) as flame retardants in LDPE/EVA nanocomposites compatibilized with amino alcohol grafted polyethylene (PEgDMAE) was studied. Morphological characterization of nanocomposites was carried out by means of X-ray diffraction (XRD) and scanning transmission electron microscopy (STEM). Flame-retardant properties of nanocomposites were evaluated by the UL-94 horizontal burning and cone calorimeter tests and limiting oxygen index (LOI). Thermal degradation behavior was analyzed with a Fourier transform infrared coupled with the thermogravimetric analyzer (TG-FTIR). The XRD analysis showed a displacement of the d₀₀₁ plane characteristic peak of clay to lower angles, which indicates an intercalated–exfoliated morphology. From STEM images it was observed a good dispersion of flame retardants (MH and ATH) throughout the polymer matrix which was reflected in flame-retardant properties. TG-FTIR showed a better thermal stability of nanocomposites and the gases evolved during combustion showed an important reduction. Based on thermal stability and thermal degradation results, the flame-retardant mechanism of LDPE/PEgDMAE/EVA/Clay/MH nanocomposites was proposed.     

固相剪切碾磨制备聚丙烯/层状双金属氢氧化物纳米复合材料的力学性能及热稳定性

采用湿法固相剪切碾磨法(S<'3>M)制备了部分剥离型聚丙烯(PP)/层状双金属氢氧化物(LDHs)纳米复合材料,研究了PP/LDHs纳米复合材料的力学性能和热稳定性.结果表明,相对于聚丙烯,固相剪切碾磨制备的PP/LDHs纳米复合材料可在拉伸强度保持不变的情况下,明显提高其断裂伸长率和冲击强度.如当LDHs质量分数为...     

阻燃聚丙烯/蒙脱土纳米复合材料的制备及性能研究

通过熔融挤出法制备出了膨胀阻燃剂/聚丙烯/有机蒙脱土(IFR/PP/OMMT)阻燃纳米复合材料,XRD分析表明,蒙脱土的层间距扩大,复合材料进入其层闻,形成了纳米复合材料;结果表明,当复合材料中IFR含量为25%时,加入4%的OMMT体系的缺口冲击强度为7.8kJ/m2,拉伸强度为25.3MPa,弯曲模量为1520MPa,极限氧指数(LOI)提高到26,而耐热性也得到提高,复合材料的综合性能最好;通过对膨胀炭层的SEM分析表明,OMMT可以使炭层更加紧密,阻燃性能进一步提高.     

Polyethylene organo-clay nanocomposites: the role of the interface chemistry on the extent of clay intercalation/exfoliation

High density polyethylene (HDPE)/clay nanocomposites have been prepared using three different functionalized polyethylene compatibilizers: an ethylene/vinyl acetate copolymer, a polyethylene grafted with maleic anhydride functions and a (styrene-b-ethylene/butylene-b-styrene) block copolymer. The nanocomposites were prepared via two different routes: (1) the dispersion in HDPE of a masterbatch prepared from the compatibilizer and the clay or (2) the direct melt blending of the three components. For each compatibilizer, essentially intercalated nanocomposites were formed as determined by X-ray diffraction and transmission electron microscopy. With the ethylene/vinyl acetate copolymer, a significant delamination of the intercalated clay in thin stacks was observed. This dispersion of thin intercalated stacks within the polymer matrix allowed increasing significantly the stiffness and the flame resistance of the nanocomposite. A positive effect of shear rate and blending time has also been put into evidence, especially for the process based on the masterbatch preparation, improving both the formation of thin stacks of intercalated clay and the mechanical properties and the flame resistance of the formed nanocomposites.     

Influence of mesoporous silica and hydroxyapatite nanoparticles on the mechanical and morphological properties of polypropylene

This paper presents the effect of different types of additives on the morphology and mechanical performance of polypropylene (PP). Three different types of nanoparticles, containing mesoporous silica (MCM-41), Hydroxyapatite (HA) and the composite of MCM-41 and HA (MH) were used. Nanocomposites containing PP, 3 wt.% of maleic anhydride grafted polypropylene (PP-g-MA) and 3 wt.% of different nanoparticles were prepared using the melt-compounding technique in a twin-screw extruder. The bulk mechanical response of the nanocomposites such as tensile, flexural and Izod impact properties were studied. The results of mechanical tests show that at the same nanomaterial content, all the nanofillers cause better tensile, flexural and impact strength than neat PP. The MH nanoparticle improves the mechanical properties of PP, better than the other nanoparticles because this nanofiller contains good properties of both MCM-41 and HA nanoparticles in itself. In order to investigate the effect of foam agent on the mechanical properties of neat PP and nanocomposites based on PP, inorganic azodicarboxamide was added to the aforementioned mixtures as chemical blowing agent and the foamed specimens were resulted using the melt-compounding technique. The results reveal that addition of foam agent to mixtures, leads to increase the flexural characteristics of samples, but the tensile properties and impact strength decrease. Scanning electron microscopy (SEM) was used to assess the fracture surface morphology and the dispersion of the nanoparticles. X ray diffractometry (XRD) was used to examine the intercalation effect on the nanocomposites. The observations show that the nanomaterials were well dispersed in the polymer matrix and the enhancement of the interface between the matrix and fillers was obtained by the incorporation of MH, MCM-41 and HA nanoparticles into PP matrix.