TPU对POM低温韧性的影响

通过熔融共混法制备出聚甲醛(POM)/热塑性聚氨酯(TPU)复合材料。采用差示扫描量热仪测试(DSC)、脆化温度测试、扫描电子显微镜(SEM)、力学性能测试分析了TPU添加量与POM复合材料结晶度和低温性能的关系。结果表明:随着TPU添加量的增加,POM/TPU的常温和低温韧性增大,当TPU含量为10%时,POM/TPU复合材料脆性温度为-39℃,在-30℃下POM复合材料的缺口冲击强度提高了47%;TPU的加入降低了POM/TPU的结晶度,对POM有良好的低温增韧作用。     

玻纤对阻燃聚甲醛复合材料阻燃性能、力学性能及流变行为的影响研究

采用熔融共混法制备了膨胀型阻燃剂(IFR)和玻纤(GF)增强改性的聚甲醛复合材料,利用垂直燃烧测试、极限氧指数测试、简支梁摆锤冲击试验机及万能力学测试仪考察了阻燃聚甲醛体系的阻燃性能及力学性能,并采用旋转流变仪测定了复合材料的流变性能。结果表明,质量分数为20%GF的加入使聚甲醛(POM)/IFR复合体系的拉伸强度提升15.8%,弯曲强度提升16.0%,冲击性能提升1倍。与未添加GF的复合体系相比,POM/IFR/GF复合材料表现出更高的动态模量和复数黏度。由于GF"烛芯效应"的作用,GF的加入未实现UL94阻燃等级。通过酚醛树脂对GF进行表面改性(m GF)后,POM/IFR/GF复合体系的极限氧指数(LOI)由22.7%提升至34.6%,力学性能略有提升,体系的模量、复数黏度均低于未改性GF增强体系。     

高光泽GF增强POM的研制

研究了聚甲醛(POM)的粘度和防玻纤(GF)外露剂的种类、含量、注塑成型工艺对GF增强POM复合材料表面光泽度的影响,测试了添加不同含量防GF外露剂复合材料的力学性能.结果表明,随着POM粘度的降低、防GF外露剂含量的增加、注射速度和压力及模温的提高,GF增强POM复合材料制品的表面光泽度逐渐提高；随着防GF外露剂含量...     

偶联剂对玻璃纤维增强POM性能的影响

研究了玻璃纤维(GF)含量、偶联剂的种类与添加量对复合材料力学性能的影响。结果表明:偶联剂的加入,不仅使GF均匀分布在聚甲醛(POM)基体中,而且使复合材料的结构及性能有较大的改善。随着偶联剂和玻璃纤维含量的增加,复合材料的力学性能明显提高。     

不同增容剂对玻璃纤维增强聚甲醛复合材料性能的影响研究

采用硅烷偶联剂γ?氨丙基三乙氧基硅烷(KH550)、γ?(2,3?环氧丙氧)丙基三甲氧基硅烷(KH560)和高分子増容剂M分别对玻璃纤维增强聚甲醛复合材料(POM/GF)进行增容改性,并通过力学性能测试、扫描电子显微镜、旋转流变仪以及差示扫描量热仪探究增容剂类型及其含量对POM/GF复合材料的力学性能、界面形貌、流变行...     

SAM和SAG对玻璃纤维增强ABS复合材料性能的影响

通过熔融共混法研究了苯乙烯-丙烯腈-马来酸酐(SAM)和苯乙烯-丙烯腈-甲基丙烯酸缩水甘油酯(SAG)两种带有反应性官能团的三元共聚物对玻璃纤维(GF)增强丙烯腈-丁二烯-苯乙烯共聚物(ABS)复合材料性能的影响。结果表明,SAM和SAG对ABS/GF复合材料都具有优异相容化效果,都可用作ABS/GF复合材料的相容型偶联剂使用。同等添加量时,添加SAG的ABS/GF复合材料具有更优异的物理力学性能,并且随着SAG添加量的增加性能提高更加明显;添加SAG的ABS/GF复合材料颜色更浅,并具有更优异的长期高温色变性。     

漆籽壳纤维含量对聚甲醛/玄武岩纤维复合材料的力学及摩擦学性能的影响

采用熔融共混、注射成型等工艺制备了聚甲醛(POM)/玄武岩纤维(BF)/漆籽壳纤维(LSSF)复合材料,通过力学试验、摩擦磨损试验和扫描电子显微镜分别研究了复合材料的力学性能、摩擦学性能和微观形貌。结果表明,LSSF和BF较均匀地分散于POM基体中,且界面相容性较好;POM/BF/LSSF复合材料的冲击性能、流动性能和摩擦性能相对于POM/BF复合材料都有一定的提高;与POM/20%BF相比,当LSSF的添加量为10%(质量分数,下同)时,复合材料的流动性能提高了68%;当LSSF添加量为15%时,复合材料的冲击性能提高了225%;当LSSF添加量为5%时,复合材料的摩擦因数降低了23%,磨损量降低了70%;复合材料的主要磨损机制由低漆籽壳含量时的磨粒磨损转变为高漆籽壳含量时的磨粒磨损和黏着磨损复合作用。     

GF增强PP/苎麻纤维复合材料的制备及其性能研究

采用非织造-模压工艺,以苎麻纤维为增强体和聚丙烯(PP)纤维制备了PP/苎麻纤维复合材料,然后添加玻璃纤维(GF)对PP/苎麻纤维复合材料进行增强改性。分别研究了不同含量苎麻纤维、GF对复合材料弯曲性能、剪切性能及吸水性能的影响,并采用扫描电子显微镜(SEM)研究了改性前后复合材料界面结合的微观形貌变化。结果表明,当PP/苎麻纤维复合材料中苎麻纤维体积分数为40%时,复合材料的弯曲、剪切性能最优;当添加体积分数为5%的GF和35%的苎麻纤维时,PP/GF/苎麻纤维复合材料弯曲强度、弯曲弹性模量、层间剪切强度分别增加18.48%,10.22%和31.41%,且复合材料吸水率最小。     

玻璃纤维对高抗冲聚苯乙烯阻燃性能的影响

以玻璃纤维(GF)为增强剂、高抗冲聚苯乙烯(HIPS)为基体,制备了一系列HIPS/GF复合材料,采用极限氧指数、锥形量热分析、扫描电镜、热重分析等方法研究了复合材料的燃烧性能。结果表明:GF的添加能使HIPS材料的极限氧指数有所提高,但其影响并不显著。随着GF用量的增加,HIPS/GF复合材料的热释放速率、总热释放量、总烟释放量和CO释放量均明显降低,同时表现出较好的阻燃和抑烟性能。GF的最佳用量约为30%,过多的GF并不能进一步提高HIPS材料的阻燃和抑烟性能。GF含量越高,HIPS/GF复合材料的质量损失速率越小,而GF的存在对HIPS的热分解行为影响很小。     

阻燃剂对UP复合材料流变性及磨损性能的影响

制备了含有氢氧化铝(ATH)、三聚氰胺多聚磷酸盐(MPP)及十溴二苯醚(DBDE)等不同阻燃剂的干式不饱和聚酯/玻璃纤维(UP/GF)共混复合材料。研究了不同阻燃剂对UP/GF复合材料的阻燃性能、流动性和磨损性能的影响,并借助SEM观察了采用不同阻燃剂的UP/GF复合材料的磨损面微观形貌。结果表明,ATH的添加质量为30%时,其UP/GF复合材料的阻燃性与DBDE添加量为25%的体系相当,达到UL94 V-0级,OLI值为30.0且具有很好的抑烟和防滴落效果;同时ATH、MPP的加入可适当提高复合材料流动性能,ATH还可以改善复合材料的磨损性能,磨损体积为未添加阻燃剂体系的50%左右。     

碳纳米纤维增强聚甲醛复合材料制备及性能

通过纳米碳纤维(CNFs)在聚甲醛(POM)基体中的均匀分散以及取向,制备了具有优异力学性能和热性能的POM/CNFs复合材料。利用扫描电子显微镜、透射电子显微镜、拉伸性能测试、热重分析、动态热机械分析测试表征了POM/CNFs复合材料的结构和力学、热学性能。结果表明,CNFs与POM分子链形成氢键相互作用,促进了CNFs在POM基体内分散,同时使POM/CNFs复合材料的结晶度显著提高。随着CNFs含量增加,POM/CNFs复合材料的拉伸强度、储能模量和损耗模量均得到提高。当添加0.5%的CNFs时,拉伸强度、储能模量及损耗模量分别提高了20.5%,127%和58%。进一步研究了高温拉伸对POM/CNFs复合材料性能的影响。结果表明,CNFs沿拉伸方向定向排列,同时复合材料拉伸后结晶度提高,拉伸强度显著增加。     

Mechanical,thermal, and dynamic mechanical properties of long glass fiber‐reinforced thermoplastic polyurethane/polyoxymethylene composites

Long glass fiber (LGF)‐reinforced thermoplastic polyurethane (TPU) elastomers and polyoxymethylene (POM) (LGF/TPU/POM) composites were prepared by using self‐designed impregnation device. Dynamic mechanical properties of the LGF/TPU/POM composites have been investigated by using dynamic mechanical thermal analysis. The results indicated that the storage modulus and glass transition temperature of the composites increase with increasing the glass fibers content and scanning frequencies. In addition, the Arrhenius relationship has been used to calculate the activation energy of α‐transition of the LGF/TPU/POM composites. The thermal stability of the LGF/TPU/POM composites was investigated by thermogravimetric analysis. The consequence demonstrated that the thermal stability increase with augmenting the content of glass fibers. The mechanical properties of the composites are investigated by a universal testing machine and a ZBC‐4 Impact Pendulum. The results demonstrated the mechanical properties of the composites aggrandize with augmenting the glass fibers content. The good dispersion of the LGFs in the matrix resins is obtained from scanning electron micrographs. POLYM. COMPOS., 35:2067–2073, 2014. © 2014 Society of Plastics Engineers     

POM/GF-MWCNTs复合材料的制备及其性能研究

将经γ氨丙基三乙氧基硅烷（KH550）处理后的多壁碳纳米管（MWCNTs）接枝到玻璃纤维（GF）表面,制成GF-MWCNTs复合填料,通过双螺杆挤出机熔融共混制备出聚甲醛（POM）/GF-MWCNTs复合材料,并对其力学性能、热性能及电性能进行了测试。结果表明,GF-MWCNTs添加量较低时,复合材料的拉伸强度和缺口冲击强度都有所提高,且分别在3 %（质量分数,下同）和1 %时达到最大值,之后则随着填料含量的增加而不断降低;当GF-MWCNTs的添加量达到10 %时,复合材料的拉伸强度和缺口冲击强度已然低于纯POM;加入GF-MWCNTs提高了复合材料的热稳定性,使POM的结晶温度和结晶度提高;GF-MWCNTs能降低复合材料的体积电阻率,但由于未在POM基体中形成逾渗网络,复合材料导电性提高并不明显。     

POM/PU/carbon nanofiber composites produced by water‐mediated melt compounding: Structure,thermomechanical and dielectrical properties

Binary and ternary composites composed of polyoxymethylene (POM), polyurethane (PU), and carbon nanofiber (CNF) were produced by water‐mediated melt compounding. PU latex and/or aqueous CNF dispersion were introduced into the molten POM in laboratory kneader to prepare toughened and/or nanoreinforced POM composites. The crystallization of the POM‐based systems was studied by polarized optical microscopy. The dispersion of the CNF was inspected in scanning electron microscopy. The mechanical and thermomechanical properties of the composites were determined by dynamic‐mechanical analysis, thermogravimetric analysis, short‐time creep‐, stress relaxation‐, and uniaxial static tensile tests. The dielectric response of the nanocomposites was investigated by means of broadband dielectric spectroscopy at ambient temperature. CNF worked as reinforcement (i.e., increased the stiffness, resistance to creep, tensile strength, and reduced the elongation at break), and also improved the thermo‐oxidative stability of POM. PU alone had an adverse effect to the above listed properties, which could be enhanced again by additional incorporation of CNF. Dielectric spectroscopy proved to be a useful tool to get deeper understanding on morphological changes caused by the additives. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Green and self-lubricating polyoxymethylene composites filled with low-density polyethylene and rice husk flour

Polyoxymethylene (POM) composites filled with low-density polyethylene (LDPE) and rice husk flour (RHF) were prepared by injection molding. The POM/5 wt % LDPE/7.5 wt % RHF composite exhibited the lowest wear rate, whereas the coefficient of friction remained low, and the POM/5 wt % LDPE/5 wt % RHF composite had the best mechanical properties. X-ray diffraction analysis was carried out, and the worn surfaces were examined with scanning electron microscopy. The results showed that the addition of the filler reduced the crystallinity degree of the POM composites. The main wear mechanism for unfilled POM was adhesion, whereas for the POM composites, wear seemed to occur mainly by fatigue and abrasion. It was experimentally confirmed that the POM composite filled with LDPE and RHF, which is well-performing, low-cost, and environmentally friendly, could be a potential material for tribological applications. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

聚甲醛/弹性体/纳米碳酸钙复合材料的制备及性能研究

采用双螺杆熔融共混的方法,以4种不同的混合顺序,制备了聚甲醛/热塑性聚氨酯弹性体/纳米碳酸钙（POM/TPU/nano-CaCO3）复合材料。通过力学性能测试、偏光显微镜、差示扫描量热仪、熔体流动速率仪和扫描电子显微镜,考察了nano-CaCO3的用量对POM/TPU(90/10)复合材料力学性能的影响,并探讨了共混方式对复合材料力学性能及微观结构形态的影响。结果表明,4 %的nano-CaCO3与TPU预先混合制成母粒再与POM共混得到的复合材料中POM晶粒发生明显细化,缺口冲击强度高达12.5 kJ/m2,冲击性能较为优异。     

Polyoxymethylene/polyurethane/alumina ternary composites: Structure,mechanical, thermal and dielectric properties

Ternary composites composed of polyoxymethylene (POM), polyurethane (PU), and boehmite alumina were produced by melt blending with and without latex precompounding. Latex precompounding served for the predispersion of the alumina particles. The related masterbatch (MB) was produced by mixing the PU latex with water‐dispersible boehmite alumina. The dispersion of the alumina was studied by transmission and scanning electron microscopy techniques (TEM and SEM, respectively) and discussed. The crystallization of POM was inspected by means of differential scanning calorimetry (DSC) and polarized optical microscopy (DSC and polarized light microscopy, respectively). The mechanical and thermomechanical properties of the composites were determined in uniaxial tensile, dynamic‐mechanical thermal analysis (DMTA), short‐time creep tests (performed at various temperatures), and thermogravimetric analysis (TGA). The melt flow of the composites was characterized in a plate/plate rheometer. In addition, the dielectric response of the nanocomposites was investigated by means of broadband dielectric spectroscopy at an ambient temperature. The composites produced by the MB technique outperformed the direct melt (DM) compounded composites in respect to the thermal and mechanical characteristics. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Performance improvement of glass-fiber-reinforced polystyrene composite using a surface modifier. II. Mechanical properties of composites

The mechanical properties of glass-fiber-reinforced polystyrene composites were investigated with the variation of glass fiber content, surface treatment conditions, and silane coupling agents. γ-MPS, GPS, and poly(γ-MPS-co-stvrene) were used for the surface modification of glass fiber. Mechanical properties of glass-fiber-reinforced polystyrene composites increased with increasing the content of glass fiber. Poly(γ-MPS-co-styrene) was superior to γ-MPS and GPS in promoting the interfacial adhesion of glass fiber-reinforced polystyrene composites. The mechanical properties of composites were maximum at a low copolymer concentration when the γ-MPS content in the copolymer was high and vice versa. © 1996 John Wiley & Sons, Inc.     

Structure and properties of polypropylene composites filled with magnesium hydroxide

Silane and silicone oil modified superfine magnesium hydroxide (MH) was filled into polypropylene (PP) as a flame retardant. The PP and flame‐retarded PP composites were studied for their mechanical properties and rheological behaviors by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), limiting oxygen index (LOI), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that the addition of MH improved flame retardancy of PP/MH composites, but seriously deteriorated mechanical properties of the composites. Surface treatment of MH could significantly improve tensile and impact strength of PP/MH composite because of its enhanced interfacial adhesion between MH and PP matrix. DSC results showed that MH had heterogeneous nucleation effect on PP. Surface treatment of MH weakened its heterogeneous nucleation effect. POM results showed that the dispersion of MH particles played an important role in the crystalline morphology and spherulite size of PP crystals. TGA indicated that MH greatly enhanced the thermal stability of PP. The introduction of treatment agent further improved the thermal oxidative stability of the composite. According to LOI, silane‐treated MH greatly enhanced flame retardancy of PP/MH composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4943–4951, 2006     

表面结构不同的纳米二氧化硅原位改性聚甲醛的研究

分别选用环氧基纳米二氧化硅（SiO2）(RNSE)和甲基纳米SiO2(DNS)为填料,通过原位聚合法制备了聚甲醛(POM)/纳米SiO2复合材料,采用场发射扫描电子显微镜、热重分析仪、差示扫描量热仪、偏光显微镜和X射线衍射仪对所得复合材料的结构、热稳定性和结晶行为进行了研究。结果表明,纳米SiO2的用量和表面结构不仅影响了其在复合材料中的分散性,而且对复合材料的热稳定性和结晶行为影响显著;当RNSE的用量少于1 %（质量分数,下同）时,其在POM基体中具有较好的分散性,且相对于DNS,RNSE的分散性更好;纳米SiO2加速了POM结晶,减小了球晶尺寸,提高了结晶度,而且RNSE比DNS对POM的结晶具有更显著的促进作用,但纳米SiO2没有改变POM的晶体结构;引入纳米SiO2降低了POM的热稳定性。