阻燃型RTV硅橡胶泡沫的制备

以107硅橡胶、含氢硅油、端乙烯基硅油、氢氧化铝、石英砂、辅助发泡剂为主要原料,在铂催化剂的催化下制成室温硫化(RTV)硅橡胶泡沫。研究了辅助发泡剂种类及用量、氢氧化铝用量、发泡温度以及乙烯基苯基硅油对硅橡胶泡沫的发泡性能、阻燃性能和耐辐照性能的影响。结果表明,当使用2.0份丙三醇作辅助发泡剂时,硅橡胶泡沫的发泡系数最大;在20℃下,硅橡胶泡沫的发泡系数最大;添加15份氢氧化铝可有效地提高硅橡胶泡沫的阻燃性能,加入15份乙烯基苯基硅油可提高泡沫硅橡胶的耐辐照性能。     

Thermal Degradation Behavior of Poly(propylene) with a Novel Silicon‐Containing Intumescent Flame Retardant

Summary: A novel intumescent flame retardant (PSiNII), containing silicon, phosphorus and nitrogen, has been synthesized and incorporated into poly(propylene) (PP). The flame retardancy of PP/PSiNII, evaluated by the limiting oxygen index (LOI) value, can be enhanced up to 29.5 vol.‐% from 17.4 vol.‐% with 20% total loading amount of PSiNII. The thermal degradation behavior of PP/PSiNII are investigated by thermogravimetric analysis (TGA) under nitrogen and air, and pressure differential scanning calorimetry (PDSC) under 1.5 MPa of oxygen. The PP/PSiNII‐3 degrades at 400 °C for different time, and the process is investigated by FTIR which indicates there is P? O in the char. The morphologies of char formed at 400 °C for 10 min and after LOI test are investigated by scanning electron microscopy (SEM). The morphological structure of the char exhibits the swollen cells in the inner and a smooth outer surface, which do good to the thermal properties and fire performance of PP. The thermal stability of PP is improved by incorporating PSiNII.

Inner surface of PP/PSiNII‐3 after LOI test.     

聚乳酸的阻燃改性研究进展

综述了近年来国内外聚乳酸（PLA）阻燃改性的研究进展,对磷系、磷氮系、硅系、膨胀型、无机纳米粉体等各种环境友好型阻燃体系在PLA树脂中的应用现状进行了概述,探讨了各自的阻燃机理,并展望了PLA阻燃改性的发展前景。     

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.     

Synthesis,Characterization, and Glass Reinforcement of Flame Retardant Acrylated Poly(Ester-Amide) and Flame Retardant Poly(Ester-Imide) Resins Based on Brominated Epoxy Resin

Bisphthalamic acids were prepared by reaction of phthalic anhydride and aliphatic diamines. Flame retardant poly(ester-amide)s were prepared by reaction of brominated epoxy resin with bisphthalamic acids and post reaction was carried out with acryloyl chloride to obtained acrylated flame retardant poly(ester-amide) resins. Bismaleimides were prepared by reaction between aromatic diamines and maleic anhydride. Carboxy terminated bismaleimides were prepared by Michael addition reaction of bismaleimides and 4-amino benzoic acid. Flame retardant poly(ester-imide)s were prepared by reaction between carboxy terminated bismaleimides and brominated epoxy resin. All the obtained products were characterized and analyzed by making composites.     

Lecithin‐enhanced biotransformation of cholesterol to androsta‐1,4‐diene‐3,17‐dione and androsta‐4‐ene‐3,17‐dione

A biotransformation process using Mycobacterium sp was studied for androsta‐1, 4‐diene‐3,17‐dione (ADD) and androsta‐4‐ene‐3,17‐dione (AD) production from cholesterol. Cholesterol has a poor solubility in water (～1.8 mg dm^?3 at 25 °C), which makes it difficult to use as the substrate for biotransformation. Lecithin is a mixture of phospholipids of phosphatidylcholine (PC) and phosphatidylethanolamine (PE), which behave like surfactants and can form planar bi‐layer structures in an aqueous medium. Therefore, a small amount of lecithin (<1 g dm^?3) can be used to form stable colloids with cholesterol at a relatively high concentration (20 g dm^?3) in water. In this work, an energy density of 1000 J cm^?3 from sonication was provided to overcome the self‐association of cholesterol and to generate a stable lecithin–cholesterol suspension that could be used for enhanced biotransformation. The lecithin–cholesterol suspension was stable and could withstand typical autoclaving conditions (121 °C, 15 psig, 20 min). In contrast to conventional surfactants, such as Tween 80, that are commonly used to help solubilize cholesterol, lecithin did not change the surface tension of the aqueous solution nor cause any significant foaming problem. Lecithin was also biocompatible and showed no adverse effect on cell growth. Compared with the medium with Tween 80 as the cholesterol‐solubilizing agent, lecithin greatly improved the biotransformation process in regard to its final product yield (～59% w/w), productivity (0.127–0.346 g dm^?3 day^?1), ADD/AD ratio (6.7–8), as well as the long‐term process stability. Cells can be reused in repeated batch fermentations for up to seven consecutive batches, but then lose their bioactivity due to aging problems, possibly caused by product inhibition and nutrient depletion. © 2002 Society of Chemical Industry     

阻燃剂双酚-A双(磷酸二苯酯)的合成

以双酚A、三氯氧磷、苯酚等廉价原料,通过两步反应合成双酚-A双(磷酸二苯酯)阻燃剂,总收率95%。采用红外光谱、核磁共振氢谱、质谱、元素分析等对产物结构进行表征。研究反应原料配比、催化剂用量、反应温度、反应时间等因素对收率的影响。适宜反应条件为:以氯化镁为催化剂,n(双酚A)∶n(催化剂)∶n(三氯氧磷)∶n(苯酚)=1∶0.01∶4.0∶5.0,第一步反应温度控制在65℃,反应时间3h;第二步反应温度控制在120℃,反应时间12h;热失重分析(TGA)表明:合成的双酚-A双(磷酸二苯酯)阻燃剂起始分解温度为299.16℃,在299.16～386.66℃和386.66～439.16℃温区迅速炭化;阻燃剂在330℃失重1%,阻燃剂被加热到427.50℃时,炭残余量为46.26%,已经达到了塑料的加工温度要求;合成的双酚-A双(磷酸二苯酯)阻燃剂阻燃性能达到UL94V-0级。     

包覆态和共混态磷酸酯/无机体系阻燃性能研究

研究了氢氧化镁、氢氧化铝或二氧化硅包覆笼状磷酸酯微胶囊以及上述3种无机阻燃剂和笼状磷酸酯复配共混用于阻燃环氧树脂的性能。采用极限氧指数,垂直燃烧（UL94）以及热分析（TG/DTG）对比了各阻燃体系的阻燃协效性能和热行为。结果表明,3种无机物在复配共混体系中都和笼状磷酸酯有较好的协同阻燃作用,而在包覆体系中阻燃性能都较差。添加量都为20 %（17 %笼状磷酸酯和3 %无机阻燃剂）,复配共混体系阻燃环氧树脂的极限氧指数可达32 %,且都可以达到UL94 V0级;而相应包覆微胶囊体系阻燃环氧树脂的极限氧指数约为24 %,阻燃级别仅达UL94 V2级。     

不同膨胀型阻燃剂改性聚丙烯/聚乳酸复合材料

用两种不同的膨胀型氮磷阻燃剂(IFR1和IFR2)阻燃改性聚丙烯(PP)/聚乳酸(PLA)复合材料。结果表明:两种阻燃剂在PP/PLA基体中都具有良好的分散性和界面粘合性。阻燃剂的加入降低了材料的力学性能,而含有25%阻燃剂的PP/PLA复合材料就能到达垂直燃烧试验(UL-94)的V0等级。燃烧过程中阻燃剂通过在材料表面形成致密的炭层来提高材料的阻燃性,其中IFR1对PP/PLA体系的阻燃改性效果更好。从力学性能和阻燃效果的双重考虑,质量含量25%的阻燃剂适合于PP/PLA材料的阻燃改性。     

A Reactive Flame Retardant as a Poly(propylene)‐Sized Glass Adhesion Promoter

Summary: Contact‐mode AFM adhesion strength measurements were employed in order to investigate the capability of PBBMA FR as an adhesion promoter in PP composites. The reactive FR exhibited superior coupling properties in comparison to conventional coupling agents such as PP‐g‐ma introduced in reinforced PP composites.

AFM image showing the recess carved out by the AFM tip in a PBBMA layer deposited on glass treated with APS.     

Flame resistant electrospun polymer nanofibers from deoxybenzoin‐based polymers

Electrospinning of 4,4′‐bishydroxydeoxybenzoin (BHDB)‐polyphosphonate was performed by varying polymer concentration, flow rate, and the distance between the charged electrode and the grounded target. High flame‐resistant nanofibers with diameters of ～ 100 nm were obtained by spinning from 65 wt % DMF solution. The nanofibers were unimodal in distribution and uniaxially aligned. The heat release capacity and char yield of the BHDB‐polyphosphonate nanofibers were 70 ± 3 J/g K, and 53%, respectively, in close agreement with the values obtained from the bulk materials. Electrospun nanofiber mats of BHDB‐polyphosphonate with high flame‐retarding properties had good mechanical strength (～ 95 MPa) and modulus (～ 3.9 GPa). © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

阻燃剂聚丙烯酸五溴苄基酯的热分解动力学

用热分析法研究了阻燃剂聚丙烯酸五溴苄基酯在空气和氮气气氛中的热分解动力学。该阻燃剂在空气气氛中为两步分解,在氮气气氛中为一步分解,利用Friedman法求出聚丙烯五溴苄基酯的第一步分解反应的活化能变化趋势,同时利用Satava-Sestak法研究了其热分解机理。结果表明,在0.10至0.90的转化率范围内,聚丙烯酸五溴苄基酯在空气气氛下的活化能为167.35kJ/mol,在氮气气氛下的活化能为171.94kJ/mol,热分解机理均为Avrami-Erofeev方程,随机成核和随后生长,反应级数分别为n=23和n=12。动力学方程分别为G(a)=[-ln(1-a)]23和G(a)=[-ln(1-a)]12。     

热塑挤出制备无机阻燃聚乙烯醇泡沫材料及其影响因素的研究

以水为增塑剂兼物理发泡剂,氢氧化铝(ATH)为无机阻燃剂兼异相成核剂,通过热塑挤出方法制备了无机阻燃聚乙烯醇/氢氧化铝(PVAL/ATH)复合泡沫材料,采用扫描电子显微镜(SEM)等研究了水和ATH含量、口模温度、螺杆转速、交联剂对复合泡沫材料泡孔结构的影响。结果表明,适当的口模温度和螺杆转速是实现体系中水的可控、连续、稳定发泡的关键因素,适量添加的阻燃剂能够起到良好异相成核剂的作用,在最佳工艺条件下,当PVAL/ATH/水为100/80/30,口模温度为125℃,螺杆转速为30 r/min时,制备得到综合性能优异的无机阻燃PVAL/ATH泡沫材料,泡沫材料的表观密度为0.32 g/cm3,膨胀倍率为10.0,泡孔密度约为1.6×105个/cm3。此外,引入硼酸作为交联剂,有效提高了熔体强度并改善了泡孔结构,交联后泡沫材料的拉伸强度和断裂伸长率分别提高到6.3 MPa和59.2%。     

A Novel Phosphorus‐Containing Poly(ethylene terephthalate) Nanocomposite with Both Flame Retardancy and Anti‐Dripping Effects

Summary: It is a big challenge to improve simultaneously both the flame retardancy and the melt‐dripping resistance of polymeric materials such as PET. In this paper, a novel intumescent flame retardant, DPSPB, was synthesized and blended with copolyester PET‐co‐DDP/O‐MMT nanocomposites, which were synthesized by polycondensation of TPA, EG, DDP, and O‐MMT. The resulting PET‐co‐DDP/O‐MMT/DPSPB nanocomposites exhibit very good flame retardance and dripping resistance, e.g., LOI = 29, UL‐94 V‐0. SEM, XRD, and XPS were used to investigate the relationships between the structures and properties of the composites. It is proved that DPSPB offers excellent protection for the structure of nanocomposites, which is responsible for the good anti‐dripping properties of the nanocomposites.

Residues of copolyesters after combustion: common nanocomposite residue of PDMN (left) and the novel nanocomposite residue of PDMN/DPSPB (right).     

聚甲基亚膦酸双酚A酯阻燃剂的合成及其应用

以甲基二氯膦和双酚A为单体,通过熔融缩聚合成了聚甲基亚膦酸双酚A酯(PMPBE)。通过傅里叶变换红外光谱(FTIR)、核磁共振谱仪、热失重分析仪(TGA)、差示扫描量热仪(DSC)、垂直燃烧仪、极限氧指数仪及微型量热仪表征了PMPBE及环氧树脂(EP)/PMPBE共混物的结构和性能。结果表明,随着PMPBE添加量的增加,复合材料的极限氧指数逐渐提高,最大放热速率和放热量逐渐降低,EP在700 ℃的残炭率明显提高。当添加20份PMPBE时,EP的极限氧指数从19.0 %提高到27.6 %,达到V-0级,最大放热速率与放热量均下降了27 %;说明该阻燃剂是良好的本征型阻燃剂。     

Zn2SnO4的制备及其对软质聚氯乙烯的阻燃研究

以结晶四氯化锡和硝酸锌为原料,通过2步煅烧法制备锡酸锌(Zn2SnO4)阻燃剂;通过极限氧指数、烟密度等级和残炭量研究了Zn2SnO4对软质聚氯乙烯（PVC）的阻燃和消烟性能的影响,同时对力学性能进行了研究。结果表明,Zn2SnO4的用量为15份时,对软质PVC的阻燃消烟效果明显,其极限氧指数可达36.0 %、烟密度等级为86.2 %、残炭率为29.7 %、拉伸强度为25.47 MPa、断裂伸长率为168 %;利用热重分析、差热分析和扫描电子显微镜等方法对阻燃PVC进一步进行表征,结果表明Zn2SnO4的加入促使软质PVC的起始分解温度降低,残炭量增加,燃烧后剩炭结构致密,阻燃效果明显。     

Microbial transformation of androst‐4‐ene‐3, 17‐dione by Bordetella sp. B4 CGMCC 2229

BACKGROUND: Microbial transformation of steroids has attracted widespread attention, especially the transformation of those steroids synthesized with difficulty by chemical methods. In this study, microbial transformation of androst‐4‐ene‐3, 17‐dione (AD) by Bordetella sp. B4 was investigated, and the effect of temperature on transformation was studied. RESULTS: Three metabolites were purified by preparative TLC and HPLC, and identified as androsta‐1,4‐diene‐3,17‐dione (ADD), 9α‐hydroxyandrost‐4‐ene‐3, 17‐dione (9α‐OH‐AD), and 3‐hydroxy‐9, 10‐secoandrost‐1, 3, 5‐triene‐9, 17‐dione (3‐OH‐SATD) by nuclear magnetic resonance imaging (NMR), Fourier transform infrared spectroscopy (FTIR) and mass spectroscopy (MS). It was first reported that the genus of Bordetella has the capability of AD degradation. Microbial transformation of AD was performed at 30 °C, 37 °C, 40 °C and 45 °C. The 9α‐OH‐AD yield reached a maximum within 16 h when the strain was cultivated in media with AD as sole carbon at 37 °C. Surprisingly, ADD was produced by the strain cultivated at 40 °C but not at 37 °C, which was different from previous reports. It was deduced that the alcohol dehydrogenase that catalyzed the transformation of AD to ADD may be temperature sensitive. CONCLUSION: Androst‐4‐ene‐3,17‐dione was converted into 9α‐hydroxyandrost‐4‐ene‐3, 17‐dione and other metabolites rapidly by Bordetella sp. B4. It is anticipated that the strain Bordetella sp. B4 CGMCC 2229 can be used in the steroids industry. Copyright © 2009 Society of Chemical Industry     

复合型阻燃剂对聚氯乙烯的阻燃抑烟作用研究

采用微胶囊红磷（MRP）、硼酸锌（ZnBO3）、氢氧化铝(ATH)和氢氧化镁(MH)进行复配对软质聚氯乙烯（PVC）进行阻燃处理,通过极限氧指数、热失重、锥形量热方法研究了不同配比阻燃剂对PVC的阻燃抑烟性能的影响。结果表明,当PVC/MRP/ZnBO3/ATH/MH质量比为100:3:1:20:20时,具有良好的阻燃抑烟效果,极限氧指数可达35.9 %;阻燃体系PVC/ATH/MH、PVC/MRP/ZnBO3/ATH/MH相对于纯PVC具有良好的阻燃抑烟性,PVC/MRP/ZnBO3/ATH/MH比PVC/ATH/MH体系在热释放、烟气、一氧化碳和二氧化碳排放指标上数值更低,热稳定性增加,成炭率更高,火灾性能指数提高,火灾蔓延指数减小,火灾危险性降低。     

两种形貌的羟基锡酸锌对聚氯乙烯的阻燃作用

以硫酸锌和锡酸钠为原料,制备了不同粒径尺寸的无定形羟基锡酸锌（ZHS）和球形ZHS;对比研究了上述2种ZHS对聚氯乙烯（PVC）的阻燃、消烟、拉伸和降解性能的影响及这2种ZHS在PVC基体中的分散情况。结果表明,当ZHS的添加量相同时,球形ZHS对PVC的阻燃、消烟和拉伸性能的有益影响优于无定形ZHS;ZHS能提高PVC的残炭率,降低其起始分解温度（T1 %）和第一阶段的最大失重峰温度（TM1）,且无定形ZHS比球形ZHS对T1 %和TM1的降低效果更明显;无定形ZHS在PVC基体中的分散性及与PVC基体结合的紧密性都优于球形ZHS。     

Flame‐Retarded Poly(propylene) with Melamine Phosphate and Pentaerythritol/Polyurethane Composite Charring Agent

In this paper, a novel intumescent system including MP as well as PER/TPU which acts as composite charring agent, is adopted to flame‐retarded PP. The encapsulation of charring agent PER by TPU effectively avoids the reaction of PER with MP during the compounding with PP at high temperature and also prevents the leaching out of polar PER from nonpolar PP matrix, thus remarkably enhancing the stability and water‐resistance of the intumescent system. PER and TPU have different but complementary charring mechanisms. So flame‐retarded PP with MP/composite charring agent shows a much better charring performance and flame‐retardancy than MP/PER flame‐retarded PP. The experimental results show that the former can reach UL‐94 V‐0 rating at 1.6 mm thickness at 25 wt.‐% flame retardant loading.