微胶囊化多聚磷酸铵的耐水性及其在聚丙烯中的阻燃性能

采用三聚氰胺-甲醛树脂(MF) 为囊材,以多聚磷酸铵（APP）为芯材制得微胶囊化多聚磷酸铵（MAPP）。耐水性及膨胀度试验表明,MAPP为膨胀型阻燃剂,APP/MF =3/1 (质量比,下同)时,MAPP在50 ℃时在水中的溶解度为0.052 g/100 mL,比APP减低了78 ％;膨胀度达到78.6 ㎝3/g。热分析表明,聚丙烯（PP）/MAPP比PP/APP的热降解速度加快,但释热量减小。由于形成蓬松多孔膨胀炭层,PP/MAPP比PP/APP的阻燃性能更佳,PP/MAPP=70/30时,其氧指数增到30.6 %。     

成炭性塑料对聚丙烯/膨胀阻燃体系的燃烧行为及阻燃性的影响

使用锥形量热仪、热重分析仪和氧指数仪研究了不同成炭剂对聚丙烯膨胀阻燃体系的燃烧行为和阻燃性的影响,得到了相关的燃烧参数。所用成炭剂包括尼龙6(PA6)、尼龙6/蒙脱土纳米复合物(PA6-nano)、热塑性聚氨酯(TPU)、酚醛树脂。实验结果表明:成炭剂对阻燃材料的燃烧行为和力学性能有很大影响;实验还发现:在PP/APP膨胀体系中添加PA6/有机蒙脱土纳米复合物(PA6-nano)后能获得较好的阻燃性。     

硼元素在膨胀型阻燃聚丙烯中的协同作用

摘要：通过燃烧性能测定、热分析和锥形量热等方法研究了硼元素在膨胀型阻燃聚丙烯（PP）中的作用。热分析表明,膨胀型阻燃剂（KDIFR）的加入明显的促进了PP成炭,使剩炭率提高,放热量减小,硼元素的引入剩炭率略有降低,放热量增大。锥形量热图表明KDIFR显著减少了PP燃烧过程的热释放速率,释热总量,及CO2和CO释放量,这种效果在硼引入后,受热燃烧初期得以促进,但随着时间的延长减弱。实验证明KDIFR使PP由聚烯烃类燃烧转变为纤维类燃烧,而硼元素的引入促进了这一转变,显著减缓了火焰传播速率,阻燃效果更加突出。     

聚丙烯/尼龙6/蒙脱石新型膨胀型纳米复合阻燃材料的研究

采用尼龙6（PA6）代替季戊四醇（PT）作成炭剂组成新型的膨胀型阻燃剂（IFR）,用熔融插层法成功制备了聚丙烯（PP）／PA6／有机化蒙脱石（OMMT）新型膨胀型纳米复合阻燃材料。用X射线衍射分析（XRD）和扫描电镜（SEM）观察OMMT层间距的变化和材料的微观结构,用热重分析（TG）、极限氧指数（LOI）测试和垂直水平燃烧测试研究了其阻燃性能,并考察了纳米复合材料的力学性能。研究结果表明,OMMT的层间距由2．200nm扩大到2、800nm,加入质量分数为4％-6％的OMMT的复合材料不仅使材料的拉伸强度和冲击强度提高了15％和69．5％,还提高了材料的阻燃性能,使剩炭率增加了12．32％,LOI达到22％,燃烧测试达HB级,其综合性能最佳。     

苯基聚硅氧烷微胶囊化聚磷酸铵的制备及其在PP中阻燃性能研究

采用苯基三甲氧基硅烷为前驱体,通过溶胶凝胶法制备出苯基聚硅氧烷微胶囊化聚磷酸铵（MAPP）。将MAPP作为阻燃剂,季戊四醇（PER）作为成炭剂,制备阻燃聚丙烯（PP）。用傅里叶红外光谱、扫描电子显微镜、能谱仪及热重分析仪对MAPP进行表征。结果表明,聚磷酸铵（APP）被苯基聚硅氧烷成功包覆;较之APP,MAPP的热稳定性和疏水性显著提高;MAPP的阻燃性能优于APP,PP/MAPP/PER复合材料达到V-0级别;阻燃剂及成炭剂的加入对PP的结晶行为有促进作用。     

相容剂在环保阻燃聚丙烯体系中的应用

在环保阻燃聚丙烯体系中加入3种不同种类的相容剂:PP蜡接枝马来酸酐(MAPP1),共聚PP接枝马来酸酐(MAPP2)和均聚PP接枝马来酸酐(MAPP3)。用熔融共混的方法制备出3种阻燃复合材料FRPP1、FRPP2和FRPP3。研究相容剂的加入对聚丙烯复配阻燃体系阻燃性能以及力学性能的影响。UL94垂直燃烧的测试结果显示,MAPP3的加入能够使PP复配阻燃体系达到V-0级别,而加入MAPP1和MAPP2的PP复配阻燃体系的燃烧级别均为V-1;同时,FRPP3的极限氧指数值(LOI)为28.4%,高于FRPP1(27.4%)和FRPP2(27.2%);锥形量热测试结果数据显示虽然FRPP1、FRPP2和FRPP3的热释放速率峰值相差不大,但是FRPP3的火灾危险系数最小,到达热释放速率峰值的时间最长,表明FRPP3的火灾安全系数最高。部分力学性能测试结果表明:MAPP3的加入能够使复配阻燃体系获得较高的拉伸强度和弯曲强度,但是在改善冲击强度方面不如MAPP1和MAPP2。     

金属氧化物对聚丙烯膨胀阻燃体系阻燃性能的影响

采用聚磷酸铵（APP）和三聚氰胺（MEL）作为聚丙烯（PP）的膨胀型阻燃剂（IFR），添加微量金属氧化物（ZnO和Cr2O3）制备出阻燃效果较好的聚丙烯阻燃材料。研究了不同含量的金属氧化物（ZnO和Cr2O3）对材料阻燃性能的影响。利用氧指数（LOI）、垂直燃烧（UL-94）、热分析（TG）、扫描电镜（SEM）研究了金属氧化物（ZnO和Cr2O3）对聚丙烯阻燃材料阻燃性能的影响、材料热降解过程的影响、在阻燃体系中的分散情况以及燃烧产物的微观结构。结果表明：添加1％ZnO和1％Cr2O3的阻燃材料，LOI分别为28％和26％；ZnO和Cr2O3的加入，改变了材料的热降解过程；ZnO使材料在燃烧时形成了连续、致密、封闭的焦化炭层，相对于Cr2O3显示出更好的阻燃效果。     

玻纤含量对无卤阻燃玻纤增强聚丙烯阻燃性能的影响

以聚丙烯（PP）为基体,加入玻纤（GF）、焦磷酸哌嗪膨胀型阻燃剂FR-1420,制备无卤阻燃玻纤增强聚丙烯（PP/GF）复合材料。通过极限氧指数（LOI）测试、垂直燃烧测试、热重分析（TG）及锥形量热测试,考察了GF含量对PP/GF的阻燃性能、热稳定性及燃烧性能的影响。结果表明：在阻燃剂含量相同下,GF含量越高,PP/GF的阻燃效果越好。当GF含量增加至25%,PP/GF的LOI提高至39.0%,0.8 mm样条垂直燃烧测试通过UL-94 V-0级。GF降低了阻燃PP/GF的初始热分解温度,但高温阶段的耐热性得到明显提高。当GF含量为25%,PP/GF在N2和空气气氛下700℃残炭率分别达到39.4%和39.0%。GF的高温残留物在锥形量热测试中起“炭层骨架”的作用,可以增加炭层的膨胀厚度,GF的加入降低PP/GF的总热释放量（THR）、总烟释放量（TSR）,提升PP/GF的火灾安全性能。     

有机化坡缕石黏土-膨胀型阻燃聚丙烯复合材料的制备及性能

制备了优异阻燃性能(LOI36%)兼具良好力学性能的膨胀型阻燃聚丙烯复合材料OPGS/PA-APP/PP。将有机化坡缕石黏土引入到哌嗪-多聚磷酸铵(PA-APP)膨胀型阻燃(IFR)聚丙烯(PP)复合材料中,通过极限氧指数(LOI)、垂直燃烧(UL-94)、热重分析法(TGA)、扫描电子显微镜(SEM)、通用电子万能试验机研究了有机化坡缕石黏土添加量对PA-APP阻燃聚丙烯复合材料阻燃性能和力学性能的影响。结果表明,添加质量分数为2%的有机化坡缕石黏土提高了该复合材料的阻燃性能和力学性能。此外,所制备样品经垂直燃烧测试可达到阻燃V-0级别。实验证明,有机化坡缕石黏土在膨胀型阻燃聚丙烯复合材料中具有明显的协效阻燃作用。     

PP/纳米SiO2复合材料的阻燃性能研究

将磷系阻燃剂1,3,5-三（5,5-二甲基-1,3-二氧杂环己内磷酸基）苯（FR）、聚磷酸铵（APP）、纳米SiO2复配,制备聚丙烯(PP)纳米复合阻燃材料。采用氧指数测定仪、水平垂直燃烧测定仪、热重分析仪、锥形量热仪对PP纳米复合阻燃材料的阻燃性能进行了研究。结果表明,FR/APP/SiO2提高了PP的氧指数、水平燃烧等级、热稳定性和残炭率,降低了热释放速率。当阻燃剂FR/APP/SiO2的总体含量为25 %,FR/APP/SiO2配比为15/7/3的情况下,PP纳米复合阻燃材料的氧指数为29.4 %,水平燃烧等级为FH-1。     

PA6含量对HDPE/PA6/MRP合金性能影响的研究

固定微胶囊化红磷（MRP）用量为11份,研究了不同尼龙6（PA6）含量对高密度聚乙烯（HDPE）／PA6／MRP合金阻燃性能、力学性能的影响,并用热重分析技术探讨了不同PA6含量时合金材料的残炭率、热降解起始温度。结果表明,当PA6含量为50份时,合金的阻燃性能、冲击强度及拉伸强度产生转变拐点,此时材料的冲击强度及残炭率最差。     

Vinyl polysiloxane microencapsulated ammonium polyphosphate and its application in flame retardant polypropylene

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.     

Using PA6 as a charring agent in intumescent polypropylene formulations based on carboxylated polypropylene compatibilizer and nano‐montmorillonite synergistic agent

The intumescent fire retardant polypropylene (IFP/PP) filled with ammonium polyphosphate (APP), melamine (M), and PA6 (charring agent) is discussed. Intumescing degree (ID) and the char yield were determined. Only when the three main components of IFR coexist at appropriate proportions, it has optimal ID and higher char yield. The appropriate proportion is PA6 : APP : M = 10 : 10 : 5. A new compatibilizer, carboxylated polypropylene (EPP), was added to PP/PA‐6 blend. Flow tests indicated that the apparent viscosity increased with the addition of EPP, thermal characterization suggested that EPP has reacted with PA6, PA6‐g‐EPP cocrystallized with PA6, and EPP‐g‐PA6 cocrystallized with PP; SEM micrographs illustrated that the presence of EPP improved the compatibility of PP and PA6. All the investigations showed that EPP was an excellent compatibilizer, and it was a true coupling agent for PP/PA6 blends. Using PA6 as a charring agent resulted in the IFR/PP dripping, which deteriorated the flammability properties. The addition of nano‐montmorillonite (nano‐MMT) as a synergistic agent of IFR enabled to overcome the shortcoming. The tensile test testified that the addition of nano‐MMT enhanced the mechanical strength by 44.3%. SEM showed that nano‐MMT improved the compatibility of the composites. It was concluded that the intumescent system with nano‐MMT was an effective flame retardant in improving combustion properties of polypropylene. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 739–746, 2006     

Rheological study of recycled polypropylene–starch blends

Blends of recycled polypropylene (PP) and starch (S) with the compositions polypropylene 83 wt%–starch 17 wt% (PP83/S17) (blend 1a), polypropylene 68.8 wt%–starch 31.2 wt% (PP 68.8/S 31.2) (blend 2a) and polypropylene 89.5 wt%–starch 10.5 wt% (PP 89.5/S 10.5) (blend 3a) were synthesized. Maleated polypropylene (MAPP) was used as a compatibilizer. The compositions of the compatibilized blends were PP73/S15/MAPP12 (blend 1b), PP55/S25/MAPP20 (blend 2b) and PP85/S10/MAPP5 (blend 3b). The occurrence of a reaction between MAPP and starch was studied using Fourier transform infrared analysis. Thermal and rheological properties such as the complex viscosity, storage and loss modulus of the blends with a compatibilizer were found to be higher than those of the blends without a compatibilizer. The compatibilized and uncompatibilized blends, as well as recycled PP, were characterized using differential scanning calorimetry, thermogravimetric analysis and cone-and-plate rheometry. The storage and loss modulus values of blend 3b were observed to be the best. The best compatibilizing effect was exhibited by blend 3b at a loading of 5 wt% MAPP because this compatibilizer content yielded the highest complex viscosity and visco-elastic behavior. The presence of a functional compatibilizer enhanced the interactions between starch and recycled PP, which was confirmed by a rise in the melt viscosity, storage modulus and thermal stability. These blends were also characterized in terms of their water uptake by performing water absorption tests. Blend 2b containing 20 % MAPP was observed to absorb the maximum amount of water at 25 °C.     

Novel milling route for controlling structure and properties in SBS elastomer blends containing dispersed PA6 and PP particles

Abstract

A novel technique to optimise the morphology and thus to enhance the mechanical properties of styrene/butadiene/styrene (SBS) triblock copolymer blends containing dispersed polyamide 6 (PA6)/polypropylene (PP) is reported. The SBS-PA6-PP composite was prepared by blending SBS with PA6-PP ultrafine powder, which was obtained by pulverising PA6 and PP in a pan mill at ambient temperature. The mechanical properties of the composite were determined and the variations of the phase structure of the composites prepared at different processing temperatures were studied by TEM. The thermooxidative stabilities of the composites were tested by thermogrivimetry (TG). The results indicate that preparing a PA6-PP ultrafine powder by the solid state mechanochemical process can improve the compatibility of PA6 with PP and SBS and accelerate the dispersion of PP and PA6 as well as their combination with SBS at the phase interface. The tensile strength of the composite can be increased greatly with an ultrafine powder content of 4-8%, while the elongation at break remains approximately constant. The variation of processing temperature causes a change in the phase structure of the plastics, which has a great effect on the properties of the composite. When the processing is carried out at the melting temperature of the PP, the PP particles combine to form a fibrillar structure that can increase the tensile strength of the matrix from 12·7 to 25 0 MPa. The temperature at which a 10% weight loss occurs in the composite increases from 396·0 to 412·7°C and the temperature of maximum weight loss increases from 454·3 to 479·3°C with an ultrafine powder content of 4%. PRC/1747     

Microencapsulated ammonium polyphosphate by polyurethane with segment of dipentaerythritol and its application in flame retardant polypropylene

Dipentaerythritol (DPER), 4, 40-diphenylmethanediisocyanate (MDI) and melamine (MEL) are used as raw materials to microencapsulate ammonium polyphosphate (MAPP) in situ polymerization. The MAPP is characterized by Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA). The results show that the coating operation can effectively improve water resistance of ammonium polyphosphate (APP), and MAPP has higher residual rate than that of APP after combustion. The flame retardant action of MAPP and APP in polypropylene (PP) is investigated by the limited oxygen index (LOI), vertical burning test (UL-94), TGA, SEM, and cone calorimeter test (CCT). The LOI value of the PP/MAPP composite at the same loading is higher than that of PP/APP composite. UL 94 ratings of PP/MAPP composites are raised to V-0 at 20 wt% loading. The results of CCT also show that MAPP is more efficient than APP. The morphological structures observed by digital photos and SEM demonstrated that MAPP could be promoted to form the continuous and compact intumescent char layer. The flame retardant mechanism of PP/MAPP is also discussed.     

热塑性聚氨酯/微胶囊化聚磷酸铵/氢氧化铝复合材料的制备及性能研究

通过溶胶?凝胶法制备了硅凝胶微胶囊化聚磷酸铵（MAPP）,并通过红外光谱仪（FTIR）、热重分析仪（TG）对MAPP进行了表征;采用熔融共混技术将氢氧化铝（ATH）和MAPP加入到热塑性聚氨酯弹性体（TPU）中,制备出系列阻燃热塑性聚氨酯弹性体（TPU/FR）复合材料,并通过TG、微型量热计（MCC）研究了TPU/FR的热稳定性和燃烧行为。结果表明,在ATH与MAPP总含量为20 %（质量分数,下同）的情况下,相对于TPU/FR1（20 % ATH）复合材料,ATH与MAPP含量分别为5 %、15 %,10 %、10 %和15 %、5 %的TPU/FR复合材料在700 oC下的残炭量分别由16.7 %提高到29.7 %、25.1 %和20.9 %;热释放容量（HRC）分别从327.1 J/（g·K）降低到154.2、164.2和170.1 J/（g·K）;对比TPU/FR2（20 % MAPP）复合材料,TPU/FR4（15 % ATH,5 % MAPP）炭渣的致密性和石墨化程度显著提高,表明ATH与MAPP复合具有显著的阻燃协同作用。     

Investigation on polypropylene and polyamide-6 alloys/montmorillonite nanocomposites

Propropylene (PP) and polyamide-6 (PA6) alloys nanocomposites were prepared using melt intercalation technique by blending PP and PA6 while used organophilic montmorillonite (OMT). The melt intercalation of PP and PA6 alloys was carried out in the presence of a compatibilizer such as maleic anhydride-g-polypropylene (MAPP). Their structures were characterized by scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM) and High Resolution Electronic Microscope (HREM). It was found different blend sequences have influence on the dispersibility of OMT and self-assembled structures of OMT appeared in PP and PA6 alloys. The crystallization behavior and crystal structure of PP and PA6 alloys/montmorillonite nanocomposites were investigated by X-ray diffraction. It showed that the blend sequences have influence on crystal structure and a higher cooling rate results in increasing of γ-crystalline phase. Flammability properties are characterized by Cone Calorimeter, which show an unusual phenomenon.     

PP/POE/PA6三元共混物相形态的预测及受混炼顺序的影响

引言对聚合物进行共混是改善其性能的重要方法,多元聚合物共混物结合了多种聚合物的优点,具有更多独特的性能,因此对多元尤其是三元共混物的研究越来越多[1-5]。聚合物共混物的相形态对其性能有着决定性的影响[6-9],因而相形态是共混物研究的一个非常重要的方面[9-12]。