无卤阻燃PES热熔胶的制备与阻燃性能

以聚磷酸铵(APP)、季戊四醇(PER)和三聚氰胺(MEL)组成的膨胀阻燃体系(IFR)作为阻燃剂,以4A分子筛作为协效剂,制备了无卤阻燃共聚酯(PES)热熔胶。研究了IFR对PES阻燃性能的影响及4A分子筛的协效作用。结果表明,少量4A分子筛可促进IFR的阻燃作用。IFR添加量为30%时,阻燃PES氧指数达30.7%,垂直燃烧达V-0级,最大热释放速率大幅降低;加入3%的4A分子筛,氧指数达35.1%。热重分析(TG)、扫描电镜(SEM)及X射线光电子能谱(XPS)结果表明,少量4A分子筛可催化IFR酯化反应,促进体系形成致密炭层,高温时4A分子筛分解并参与成炭反应,稳定炭层。     

分子筛/受阻胺对膨胀阻燃聚丙烯的协同阻燃作用

采用热失重、极限氧指数、锥形量热研究了以受阻胺(NOR116)和分子筛为协效剂,与聚磷酸铵(APP)/季戊四醇(PER)在聚丙烯基体中的热降解行为及协同阻燃性;并用拉曼光谱和扫描电镜分析了残炭的结构和形貌,进一步研究了其协同阻燃机理。结果表明,NOR116/分子筛协效阻燃体系可明显提高极限氧指数并改善燃烧时熔滴缺陷,显著降低热释放速率、烟释放速率;NOR116可有效提高PP的初始分解温度及最大分解速率温度,使膨胀阻燃体系后期的交联成炭及气体释放更加匹配;在燃烧过程中分子筛与膨胀阻燃体系形成了Si-P-Al-C的结构,可有效稳定炭层;拉曼光谱及扫描电镜结果表明,NOR116和分子筛可促进膨胀阻燃体系形成致密且高石墨化程度的炭层,有效阻隔了氧气的进入及热的反馈。     

SiO2和Al2O3对PP/APP/PER膨胀阻燃体系的协同作用

聚丙烯／聚磷酸铵／季戊四醇(PP／APP／PER)是一典型的无卤膨胀体系,文中结合氧指数(LOI)及热失重分析(TGA)实验配合锥形量热仪(CONE)研究了SiO2和Al2O3对该膨胀体系阻燃、抑烟的协同作用。与文献[1]的比较表明,不具有分子筛笼形结构的SiO2或Al2O3同样也具有促进PP／APP／PER体系凝缩相快速成灰、稳定炭层、降低热释放及烟释放的作用;说明硅铝酸盐的物理结构不是影响膨胀阻燃协同作用的主要因素。     

2-Mercaptothiazoline modified mesoporous silica for mercury removal from aqueous media

Mesoporous silicas (SBA-15 and MCM-41) have been functionalized by two different methods. Using the heterogeneous route the silylating agent, 3-chloropropyltriethoxysilane, was initially immobilized onto the mesoporous silica surface to give the chlorinated mesoporous silica Cl-SBA-15 or Cl-MCM-41. In a second step a multifunctionalized N, S donor compound (2-mercaptothiazoline, MTZ) was incorporated to obtain the functionalized silicas denoted as MTZ-SBA-15-Het or MTZ-MCM-41-Het. Using the homogeneous route, the functionalization was achieved via the one step reaction of the mesoporous silica with an organic ligand containing the chelating functions, to give the modified mesoporous silicas denoted as MTZ-SBA-15-Hom or MTZ-MCM-41-Hom. The functionalized mesoporous silicas were employed as adsorbents for the regeneration of aqueous solutions contaminated with Hg (II) at room temperature. SBA-15 and MCM-41 functionalized with MTZ by the homogeneous method present good mercury adsorption values (1.10 and 0.7mmolHg (II)/g of silica, respectively). This fact suggests a better applicability of such mesoporous silica supports to extract Hg (II) from aqueous solutions. In addition, it was observed the existence of a correlation between mercury adsorption with pore size and volume since, SBA-15 with lower areas and higher pore sizes functionalized with sterically demanding ligands, show better adsorption capacities than functionalized MCM-41.     

Mesoporous silica nanoparticles inhibit cellular respiration

We studied the effect of two types of mesoporous silica nanoparticles, MCM-41 and SBA-15, on mitochondrial O 2 consumption (respiration) in HL-60 (myeloid) cells, Jurkat (lymphoid) cells, and isolated mitochondria. SBA-15 inhibited cellular respiration at 25-500 microg/mL; the inhibition was concentration-dependent and time-dependent. The cellular ATP profile paralleled that of respiration. MCM-41 had no noticeable effect on respiration rate. In cells depleted of metabolic fuels, 50 microg/mL SBA-15 delayed the onset of glucose-supported respiration by 12 min and 200 microg/mL SBA-15 by 34 min; MCM-41 also delayed the onset of glucose-supported respiration. Neither SBA-15 nor MCM-41 affected cellular glutathione. Both nanoparticles inhibited respiration of isolated mitochondria and submitochondrial particles.     

Effect of flame retardants on flame retardant,mechanical, and thermal properties of sisal fiber/polypropylene composites

A flame retardant efficiency of flame retardants; ammonium polyphosphate (APP), magnesium hydroxide (Mg(OH)₂), zinc borate (Zb), and combination of APP with Mg(OH)₂ and Zb in sisal fiber/polypropylene (PP) composites was investigated using a horizontal burning test and a vertical burning test. In addition, maleic anhydride grafted polypropylene (MAPP) was used as a compatibilizer to enhance the compatibility in the system; i.e. PP-fiber and PP-flame retardants. Thermal, mechanical, and morphological properties of the PP composites were also studied. Adding the flame retardants resulted in improved flame retardancy and thermal stability of the PP composites without deterioration of their mechanical properties. APP and combination of APP with Zb effectively enhanced flame retardancy of the PP composites. No synergistic effect was observed when APP was used in combination with Mg(OH)₂. SEM micrographs of PP composites revealed good distribution of flame retardants in PP matrix and good adhesion between sisal fiber and PP matrix.     

微胶囊化膨胀型阻燃剂与有机蒙脱土协效阻燃乙烯-醋酸乙烯共聚物性能

通过纳米复合的方式,将微胶囊化的膨胀型阻燃体系—聚磷酸铵(APP)-季戊四醇(PER)与有机改性的片层蒙脱土(OMMT)用于协效阻燃乙烯-醋酸乙烯共聚物(EVA)。采用XRD、TEM、TGA、极限氧指数(LOI)、垂直燃烧(UL-94)、锥形量热仪、烟密度和动态机械热分析对微胶囊化APP(MCAPP)-微胶囊化PER(MCPER)-OMMT/EVA复合材料的结构与性能进行研究。研究结果表明,OMMT被完全剥离开,并以层离或插层的状态分散在EVA中;MCAPP-MCPER与OMMT之间存在明显的协效阻燃作用,用3wt%OMMT代替MCAPP-MCPER后,MCAPP-MCPER-OMMT/EVA复合材料的LOI值从25.5vol%提高到29.5vol%,垂直燃烧结果由V-2上升到V-0级别,残炭量也由14.5wt%增大到15.9wt%,烟密度由154.7 g/s降低到97.5 g/s,材料的阻燃性能得到有效提高。此外,万能拉伸测试及动态机械热分析测试表明,通过纳米复合制备的阻燃MCAPP-MCPER-OMMT/EVA复合材料具有更好的力学和动态热机械性能。      

可膨胀石墨改性APP/PER/EN防火涂料热降解行为

采用可膨胀石墨 (EG) 对APP/PER/EN防火体系进行改性,制备成一种新型EG改性APP/PER/EN防火涂料。运用示差热分析 (DTA) 、热重分析 (TG) 、扫描电镜分析 (SEM) 、能谱分析 (EDS) 和隔热性能试验分析研究APP/PER/EN防火涂料和EG改性防火涂料的热降解行为、残余炭体元素含量、成炭率和隔热性能。EG改性防火涂料的APP-PER-EN之间的化学反应膨胀过程与可膨胀石墨物理膨胀过程作用温度范围接近,能产生很好的协同配合作用。膨胀石墨提高了APP/PER/EN防火涂料炭质层的成炭率、抗氧化性和热稳定性。EG添加量过高 (≥15%) 会造成燃烧后期炭质层脱离基材。10% EG (质量分数) 添加量能有效提高APP/PER/EN防火涂料的隔热防火性能。      

介孔分子筛和Cr_2O_3协同膨胀阻燃体系对阻燃天然橡胶性能的影响

用介孔分子筛(MCM-41)和Cr_2O_3协同膨胀型阻燃体系(IFR)对天然橡胶(NR)进行阻燃。为研究MCM-41和Cr_2O_3的阻燃协同作用,使用不同组分的两种协效剂协同IFR阻燃天然橡胶。对阻燃体系分别进行氧指数测试、热重分析、锥形量热分析、拉伸测试和残炭扫描分析。研究结果表明:天然橡胶单纯添加IFR时,其力学性能大幅下降,热学性能也没有显著提升。然而随着Cr_2O_3和MCM-41添加量的增加,橡胶基体的拉伸强度和断裂伸长率均有所改善,在IFR添加量为36%(与天然橡胶的质量比)、MCM-41添加量为1%,Cr_2O_3为3%时,IFR-MCM-41-Cr_2O_3复合阻燃剂的阻燃效果最好,热释放速率峰值和热释放总量均明显下降,IFR-MCM-41-Cr_2O_3/NR复合材料燃烧后,炭层发泡均匀且致密,极限氧指数(LOI)可以达到26.5%,垂直燃烧(UL-94)为V-0级。     

Effect of flame retardants on mechanical properties,flammability and foamability of PP/wood–fiber composites

The mechanical properties, flame retardancy, thermal degradation and foaming properties of wood–fiber/PP composites have been investigated. Ammonium polyphosphate (APP) and silica were used as flame retardants. The limiting oxygen index (LOI), thermal gravimetric analysis (TGA) and cone colorimeter (CONE) were employed for the study of fire retardance. At the same time, wood–fiber/PP composite foams were produced with the batch foaming technique using CO₂ as blowing agent. The effects of APP and silica content, pressure and temperature on the final cell structure were investigated. According to LOI, TGA and cone calorimeter results obtained from the experiments, APP and silica are effective flame retardants for wood–fiber/PP composites, and silica was shown to have a flame retardant synergistic effect with APP in wood–fiber/PP composite. The mechanical properties of the composites decreased with addition of flame retardants, except for the tensile strength of small amount of silica filled wood–fiber/PP composite. The results also revealed that the cellular morphologies of the foamed wood–fiber/PP composites are a strong function of the content of APP and silica as well as foaming conditions.     

膨胀型阻燃剂对硫化天然胶乳胶膜力学性能和阻燃性能的影响

以聚磷酸铵(APP)、季戊四醇(PER)和三聚氰铵(MEL)组成膨胀型阻燃体系(IFR),考察阻燃剂配比及用量对硫化天然胶乳力学性能和阻燃性能的影响,并通过热重分析仪分析其热稳定性、扫描电镜(SEM)分析阻燃剂在胶乳中的分散效果。结果表明,添加PER和MEL的硫化胶膜力学性能很好,但阻燃性能较差;添加APP和IFR的硫化胶膜力学性能较差,但是阻燃性能很好;SEM观察发现APP与橡胶相容性差;热失重分析可知,改性的硫化胶膜比未改性的硫化胶膜的阻燃性好,且IFR改性硫化胶膜的阻燃效果是最好。     

4A分子筛对PP/MPP/PEPA膨胀阻燃体系的协同作用

以4A分子筛为阻燃协效剂,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4A分子筛用量对PP阻燃性能和协同作用的影响。结果表明:添加少量的4A分子筛即可显著提高PP的阻燃性能;当MPP/PEPA/4A分子筛添加量分别为12%、8%和2%时,阻燃PP的氧指数高达33。TGA、FTIR分析和体视显微镜及SEM观测结果表明:添加少量的4A分子筛可以催化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。     

TiO_2对PP/MPP/PEPA膨胀阻燃体系的协同作用

以TiO2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聚丙烯(PP)。研究了TiO2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TiO2即可显著提高PP的阻燃性能;当MPP/PEPA/TiO2添加量分别为12%、8%和1%时,阻燃PP的氧指数高达31.5。TGA和FTIR分析及SEM和体式显微镜观测结果表明:添加TiO2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。     

含硅化合物与膨胀阻燃剂协同阻燃聚丙烯

采用聚磷酸铵(APP)与季戊四醇(PER)复合膨胀阻燃剂(IFR)阻燃聚丙烯,研究了不同含硅物质——硅胶(SG)、硅酮(GM)以及硅晶(SW)纤维对IFR阻燃PP性能的影响,并通过LOI、UL-94、TGA对材料阻燃性能进行了表征。结果表明,三种物质与IFR都存在一定的协同效应。然而,硅胶与IFR的协同效应最好,在IFR含量为25%时,添加2%的硅胶,材料氧指数由29提高至35,UL-94也提高至V-0级,材料的高温热稳定性也得到了极大提高,并且能够生成结构更加致密的炭层。     

有机蒙脱土协同含磷木质素基成炭剂阻燃聚乳酸

将自制含磷木质素基成炭剂（Lig-P）和聚磷酸铵（APP）复配用于制备阻燃聚乳酸（PLA）基复合材料,考察了协效阻燃剂有机蒙脱土（OMMT）对阻燃PLA性能的影响。采用极限氧指数（LOI）仪、垂直燃烧（UL-94）测试仪、锥形量热仪、热失重分析仪分别对Lig-P-APP-OMMT/PLA阻燃复合材料的阻燃性能、热稳定性能和燃烧行为进行了研究。结果发现,OMMT与Lig-P-APP存在明显的协同阻燃作用,当OMMT替代3wt%的Lig-P-APP时,Lig-P-APP-OMMT/PLA阻燃复合材料的LOI由27%增加至32%,UL-94等级由V1级提高至V0级;且Lig-P-APP-OMMT/PLA阻燃复合材料的最大热降解速率有所降低,800℃的残炭量提高了将近50%;此外,OMMT的引入使PLA阻燃复合材料的热释放速率明显降低,热释放速率峰值（PHRR）、烟释放速率峰值（PSPR）及总烟释放量（TSR）分别降低了26.4%、60%及26.3%。OMMT可明显提高阻燃PLA炭层的致密度及石墨化程度。      

Mesoporous silicates as nanoreactors for carbon nanotube production in the absence of transition metal catalysts

Carbon nanotubes were produced from either a template or the polymer-filled pore systems of mesoporous silicates of various structures and dimensions by heat treatment in the absence of air. Successful synthesis was done when the template molecules contained little or no oxygen. For SBA-15 material, where the structure-directing molecule used for synthesis of mesoporous silicate was polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer, no carbon nanostructures were formed. A peculiar carbon nanostructure was generated from the template for pore expanded MCM-41. To demonstrate carbon nanotube formation from polymer in the mesoporous silicates, the mesopores of MCM-41, MCM-48, and SBA-15 silicates were filled with divinyl-benzene polymer and then graphitized at 1300 K. The polymer was successfully transformed into carbon nanotubes for the MCM class silicate but not the SBA-15 silicate.     

淀粉对聚乙烯膨胀阻燃体系降解和阻燃的影响

以淀粉作为膨胀阻燃体系中的成炭剂,聚代或部分代取了膨胀型阻燃剂中的季戊四醇,研究了淀粉对膨胀阻燃剂及其与线性低密度聚乙烯膨胀体系的热降解行为和阻燃性。研究表明,聚磷酸铵可明显地改变淀粉的热降解行为促进成炭;尽管淀粉可提高ＩＦＲ的成炭量和膨胀体系的膨胀倍数,但它却在一定程度上降低了ＬＬＤＰＥ的膨胀体系的阻燃性,也即是降低了极限氧指数和提高了热释放速率峰值,而用淀粉部分取代ＰＥＲ,对其阻燃性很小,可用     

增容剂EVA-g-MAH对乙烯-醋酸乙烯共聚物/聚酰胺6阻燃合金性能的影响

采用熔融共混法,以聚磷酸铵(APP)、季戊四醇(PER)为原料组成的膨胀阻燃剂(IFR),制备了乙烯-醋酸乙烯共聚物/聚酰胺6/IFR(EVA/PA6/IFR)阻燃复合材料,并研究了增容剂EVA-g-MAH对EVA/PA6阻燃合金阻燃性和力学性能的影响。通过极限氧指数、垂直燃烧、熔融指数、力学性能、热重分析和扫描电子显微镜等手段对EVA/PA6阻燃合金进行了性能测试与表征。结果表明:随着EVA-g-MAH用量的增加,EVA/PA6阻燃合金的极限氧指数稍有降低,但当EVA-g-MAH质量分数为10%时,垂直燃烧可达UL 94V-0级;拉伸强度和断裂伸长率随着增容剂含量的增加而逐渐升高。热重分析结果表明,增容剂可提高EVA/PA6阻燃合金的热稳定性。     

高结晶规则大孔硅的制备和应用

ＦＳＭ－１６,ＭＣＭ－４１和ＳＢＡ－１５等具有高规则二维六角晶格的多孔硅可用不同硅源和表面活性剂合成,其孔径可达１０,１５或３０ｎｍ,可用具有不同熔基链长的表面活性剂和膨胀剂控制。其结晶规则性随孔径的增大而降低。用层状硅土Ｋａｎｅｍｉｔｅ制备的ＦＳＭ－１６和来自水玻璃的ＭＣＭ－４１,其表面阴离子度比用四甲氧基硅烷（ＴＭＯＳ）制备的ＳＢＡ－１５高得多。如将在等电点以下呈阴离子性的生物酶插入硅孔,则由于离子间的相互作用和氢键结合力,可得到结合得十分稳定的生物／无机陶瓷结合体。以此结合体为有机酸化反应的催化剂,反应的活性很高。     

Synthesis of Highly Ordered Large Size Mesoporous Silica and Effect of Stabilization as Enzyme Supports in Organic Solvent

The FSM-16, MCM-41 and SBA-15 type hexagonal mesoporous silica materials having a highly arrange in order of the 2-dimensional structure were synthesized by using different silicon sources and surfactants. In the 2-dimensional silicate framework, pore size can be uniformly controlled by the combined use of the surfactants having different alkyl chains length and swelling agents (triisopropyl benzene). Pore-diameter of FSM-16 and MCM-41 can be expanded to 100 A, SBA-15 is 150 A. Crystal regularity decreased with increasing the pore-diameter in the FSM-16 derived from Kanemite (silicon source) and MCM-41 from water glass, its anionic char-acteristics on the pore wall may be higher than SBA-15 derived from oligomeric tetramethoxysilane (TMOS) is also reported. We have successfully used FSM-16 and MCM-41 as immobilizing agents of enzyme having cationic residues under isoelectric point. The level of adsorption of enzymes in the FSM-16 and MCM-41 was relatively high, but was low in the SBA-15 support. The mechanism of enzyme adsorption in mesopore was suggested to be the ionic interactions. In aqueous solutions, horseradish peroxidase (HRP) immobilized in FSM-16 containing 89A mesopore showed the highest loaded amounts(183mg/mg FSM),then a FSM-16 of pore-diameter 30 A only loaded a litter amounts (28mg/mg FSM) on the outside surface. The catalytic activity in organic solvent is high when HRP was immobilized in FSM-16 and MCM-41, but is low in case of SBA- 15.