SCM晶须/高密度聚乙烯复合材料力学性能的研究

研究了硅钙镁晶须(SCM晶须)／高密度聚乙烯(HDPE)复合材料的力学性能。实验结果表明：随着SCM晶须用量的增加，复合材料的拉伸强度、弯曲强度、弯曲模量显著提高而缺口冲击强度稍有降低；利用改性聚乙烯作增容剂，可以改善基体树脂与SCM晶须的界面结合性，有助于力学性能的提高。     

硅钙镁晶须填充聚丙烯复合材料的性能研究

在啮合同向双螺杆挤出机中制备了聚丙烯（PP）/硅钙镁（SCM）晶须复合材料,研究了硅烷偶联剂用量、SCM晶须含量对复合材料力学性能以及熔体流动性能的影响。实验结果表明,当硅烷偶联剂用量占晶须的2 ％（质量分数,下同）时,PP与SCM晶须的配比为80/20（质量比,下同）时,PP/SCM晶须复合材料的拉伸强度、弯曲强度和冲击强度等综合力学性能最佳。     

长玻纤增强反应注射成型PU泡沫塑料的力学性能

利用高压喷灌机开展了长玻纤增强硬质聚氨酯泡沫塑料(RPUF)的成型技术研究。结果表明:RPUF的弯曲模量随着玻纤用量的增加而增大;密度为0.75 g/cm3的RPUF的弯曲强度随玻纤用量的增加而减小,密度为0.95g/cm3的RPUF的弯曲强度随玻纤用量的增加而增大,当玻纤质量分数大于40%时,弯曲强度开始下降;在载荷垂直于玻纤的分布方向,RPUF的压缩模量随着玻纤用量的增加先增大后减小,在载荷平行于玻纤分布方向,压缩模量随着玻纤用量的增加而增大;RPUF的压缩强度随着玻纤用量的增加而减小;RPUF的压缩强度和压缩模量在载荷平行于玻纤分布方向明显高于载荷垂直于玻纤分布方向;随着玻纤用量和长度的增加,RPUF的冲击强度均明显提高。     

ABS/镁盐晶须复合材料的研究

以（乙烯／乙酸乙烯酯／苯乙烯）三元共聚物（BS树脂）为增容荆，采用双螺杆挤出机制备了（丙烯腈／丁二烯／苯乙烯）共聚物（ABs）／镁盐晶须复合材料，研究了BS树脂、镁盐晶须用量对复合材料力学性能、流动性能的影响、结果表明，加入BS树脂有利于提高复合材料的拉伸强度和冲击强度，复合材料的熔体流动速率（MFR）随BS树脂用量增加而增大，且其MFR对温度或负荷呈非线性函数关系，比ABS对负荷更为敏感．     

镁盐晶须/聚丙烯复合材料的研究

研究了镁盐晶须／聚丙烯复合材料的力学性能和耐热性能。结果表明：随着镁盐晶须用量的增加，复合材料的拉伸强度、弯曲强度、弯曲模量及热变形温度显著提高，而简支梁缺口冲击强度基本保持不变。利用马来酸酐接枝聚丙烯作为相容剂，可以改善基体树脂与镁盐晶须的界面结合性，有助于提高力学性能。     

CaCO3晶须补强增韧不饱和聚酯树脂的研究

针对不饱和聚酯树脂（UPR）强度低、脆性大等缺陷,用添加碳酸钙晶须的方法对其进行改性,研究了碳酸钙晶须用量对树脂复合材料力学性能的影响。结果表明：当CaC03晶须的掺量为5％时,UPR／CaCO3晶须复合材料的拉伸强度、弯曲强度达到极大值39．2MPa、52．7MPa,比树脂基体分别提高了126％和73％;当CaCO3...     

硅类表面活性剂对聚氨酯硬泡性能的影响

选用具有不同极性链(聚氧化烯烃链段)长度的聚硅氧烷–聚氧化烯烃嵌段共聚物结构的硅类表面活性剂(具有不同极性),研究了表面活性剂的极性对硬质聚氨酯泡沫塑料(RPUF)表观密度、尺寸稳定性、流动性能、压缩强度、保温性能的影响。结果表明,表面活性剂过低的分子极性会引起消泡现象,不利于发泡过程的进行;RPUF的表观密度和压缩强度随着表面活性剂极性的增大而增大;表面活性剂极性大的RPUF表现出更好的高、低温尺寸稳定性,在温度变化时更不容易发生变形;随着表面活性剂极性的增加,RPUF的保温性能和流动性能有所下降。     

PP/Al(OH)3/Mg(OH)2复合材料阻燃性能研究

制备了PP（聚丙烯）/Al（OH）3/Mg（OH）2／硼酸锌和PP／Al（OH）3／Mg（OH）2阻燃复合材料,并测定了复合材料的氧指数（OI）、水平燃烧速度和烟密度。结果表明,OI随着阻燃剂质量分数的增加而升高,随着粒径的增大而降低;燃烧速度随着阻燃剂用量的增加而下降,随着粒径的增大先升后降;烟密度随着阻燃剂用量的增加而降低,随着粒径的增大而增大;添加硼酸锌后具有显著的抑烟效果。     

PHBV/CSH晶须复合材料的制备、表征及3D打印性能

分别制备了半水硫酸钙(CSH)晶须和聚羟基丁酸戊酸共聚酯(PHBV)/CSH晶须复合材料,并研究了CSH晶须用量对PHBV/CSH晶须复合材料流变性能、结晶性能、力学性能和表面形貌的影响。结果表明:通过水热-盐溶液法制备的CSH是典型的α型晶须,其长度为10~15μm,宽度为1~2μm,是聚合物增强的理想材料;PHBV/CSH晶须复合材料的表观黏度分别随着温度和剪切速率的提高而逐渐下降;CSH晶须使PHBV/CSH晶须复合材料的结晶温度和结晶度明显提高,但其熔融温度有所下降。此外,CSH晶须显著改善了3D打印PHBV/CSH晶须复合支架的压缩性能,在CSH晶须用量为20%时,其压缩强度提高了3倍,增强效果显著;SEM结果显示,PHBV/CSH晶须复合材料表面随着CSH晶须用量的增加逐渐变粗糙。     

硼镁酸晶须增强镁基复合材料力学性能研究

采用粉末冶金结合热挤压的方法制备了Mg2B2O5／AZ91D镁基复合材料。研究了不同质量分数的晶须添加量对于复合材料的显微组织、抗压强度、显微硬度及摩擦磨损性能的影响。实验结果表明Mg2B2O5晶须在基体中均匀分布，组织致密。显微硬度实验中，随着晶须加入量的增加，显微硬度呈现逐渐升高的趋势。抗压实验中，随着晶须含量的增加，在变形量相同时，复合材料的抗变形能力呈现先增加后降低的的趋势。复合材料的磨损机制主要是磨粒磨损结合氧化磨损。     

A study of rigid polyurethane foams: The effect of synthesized polyols and nanoporous graphene

Rigid polyurethane foams (RPUF) with nanoporous graphene (NPG) were synthesized and their properties, including density, mechanical, morphological, and thermal‐resistant properties were studied. In the current work, polyols of the RPUF formulation were synthesized and NPG content was varied from 0.1 to 0.5 wt %. Scanning electron microscopy (SEM) observation was used to observe the dispersion of NPG and cell size in the RPUF nanocomposites. Only 0.25 wt % of NPG improved compressive strength and modulus respectively by 10.7% and 66.5%. The TGA analysis confirmed that an increase in NPG loading slightly increase the degradation temperature of the samples. These results additionally indicated that NPG enhances the mechanical properties of the RPUF nanocomposites more effectively compared to other nanoparticles (clay, silica etc.). The superiority of NPG over other nanoparticles can be attributed to unique two‐dimensional geometrical morphology and a higher specific surface area. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45001.     

Expandable Graphite For Halogen-Free Flame-Retardant of High-Density Rigid Polyurethane Foams

We obtained the high-density rigid polyurethane foam (RPUF) filled with expandable graphite (EG) by airtight cast molding, and its fire performance was evaluated. The results show that the LOI values increase linearly with EG content, especially the LOI value of the 20 wt% EG-filled RPUF composites increases rapidly to 39.5% from 22.5% of pure RPUF. When the pure RPUF was burned, no clear transition process between burning spots and virgin material is observed. But when the EG/RPUF composite was burned, EG produced high-volume expanded graphite and covered the surfaces of the materials, which can prevent combustible gases from feeding the flame, and it also separates oxygen from the burning material efficiently. The thermal degradation of foam was investigated using thermogravimetric analysis (TGA). The result shows that the thermo-oxidative degradation of pure RPUF takes place in the range of 220–350°C and 450–650°C, respectively. The thermal stability of RPUF composites increased slightly when it contained 20 wt% EG. The mechanical and electrical properties of EG/RPUF were also discussed. Generally, addition of EG resulted in a slight decrease in the mechanical properties and no influence on the electrical conductivity.     

碱式硫酸镁晶须填充尼龙6复合材料研究

研究了碱式硫酸镁晶须用量和偶联剂对碱式硫酸镁晶须填充尼龙6复合材料力学性能、熔体流变性能和阻燃性能的影响。结果表明，经过硅烷偶联剂表面处理的晶须比钛酸酯偶联剂处理的晶须对尼龙6有更好的的改性效果；随着晶须用量的增加，复合材料的拉伸强度和缺口冲击强度都是先增加后降低，分别在晶须质量分数为40％和20％时达到最大值；复合材料的阻燃性能随晶须用量的增加而改善，碱式硫酸镁晶须的最佳用量为25％～40％。     

四脚状氧化锌晶须增强尼龙6复合材料的研究

制备了四脚状氧化锌（T－ZnO)晶须增强尼龙6复合材料，详尽地研究了晶须的表面处理、晶须增强尼龙6复合材料的力学性能、耐热性及尺寸稳定性，并用扫描电镜对复合材料的拉伸断口进行了观察。研究表明：用KH－550作为该体系的偶联剂，其加入量为－．5％为宜；T－ZnO晶须的加入可提高尼龙的拉伸强度，增加尺寸稳定性及耐热性。     

膨胀石墨填充硬质聚氨酯泡沫塑料的研究

对膨胀石墨(EG)填充硬质聚氨酯泡沫塑料(RPUF)泡孔结构和填料分散情况进行了分析,研究了EG对RPUF的微观结构形态、泡孔平均直径和泡孔直径分布的影响;同时研究了EG对RPUF的压缩力学性能和电学性能的影响,并分析其压缩破坏的机理。结果表明：EG使RPUF泡孔平均直径减小,泡孔尺寸分布减小,EG在反应体系中充当泡孔成核剂,石墨片层间距离小,并未形成插层复合结构。随EG用量的增加,RPUF的压缩强度和压缩模量轻微下降。不同膨胀倍率的EG对其压缩强度和压缩模量没有影响;EG填充RPUF的体积电阻没有变化,对其导电性能没有影响。     

Enhanced mechanical and thermal properties of rigid polyurethane foam composites containing graphene nanosheets and carbon nanotubes

The comparative study of rigid polyurethane foam (RPUF) nanocomposites based on graphene nanosheets (GNSs) and carbon nanotubes (CNTs) has been reported. A GNS content of 0.3 wt% in polyol turns to be optimal for its foamability with the isocyanate component, as verified by rheology measurements. Scanning electron microscopy and transmission electron microscopy observations reveal a homogeneous dispersion of GNSs and CNTs in the RPUF nanocomposites. Only 0.3 wt% loading of GNSs and CNTs led to 36% and 25% improvement respectively in the compressive modulus of the RPUF nanocomposites. Meanwhile, 16 °C and 14 °C improvements in the glass transition temperature confirm the important role of both the nanofillers in the heat resistance of RPUF nanocomposites. These results additionally indicate that GNSs work more effectively than CNTs in mechanical property and heat resistance enhancement of the RPUF nanocomposites. The superiority of GNSs over CNTs can be attributed to their wrinkled surface structure, unique two‐dimensional geometrical morphology and higher specific surface area, which results in stronger interaction and restriction of segmental motion at the interface between the GNSs and the RPUF matrix. In addition, changes in the thermal conductivity of the nanocomposites are negligible, indicating that incorporation of GNSs and CNTs will not hinder the application of RPUF nanocomposites as thermal insulators. On the contrary, the enhancement in mechanical properties and heat resistance will undoubtedly expand the application range of polyurethane foam materials. Copyright © 2012 Society of Chemical Industry     

Thermal stability,flame retardancy and rheological behavior of ABS filled with magnesium hydroxide sulfate hydrate whisker

Summary Halogen-free and flame-retardant acrylonitrile–butadiene–styrene copolymer (ABS) composites were prepared using magnesium hydroxide sulfate hydrate (MHSH) whisker as a flame retardant, and the effect of zinc stearate (ZnSt₂) as a dispersion additive on the morphology and properties of the ABS/MHSH composites was studied. The morphology observation by using scanning electronic microscope (SEM) indicates that the addition of zinc stearate could improve the dispersion of the MHSH whisker in ABS matrix. Cone analysis results show that the heat release rate (HRR) and mass loss rate (MLR) of the composites decrease considerably with increasing MHSH whisker content. The composite with zinc stearate has lower HRR than the composite without zinc stearate, indicating the better dispersion of MHSH whisker could improve the flame retardancy of ABS composites. SEM observation results show that the char residue of ABS/MHSH composites retain its fibrous appearance. Thermogravimetric analysis (TGA) shows that the presence of MHSH enhanced thermal stability of the composites obviously. The viscoelastic behavior of the composites was measured by using a parallel plate rheometer. With increasing MHSH whisker content, the viscosity, storage modulus of the composites increase at low frequency zone, and ABS/MHSH composites exhibit more distinct solid-like response at terminal zone than ABS. The presence of zinc stearate leads to slight increases in the storage modulus.     

全水发泡阻燃聚氨酯硬质泡沫塑料的制备与性能

采用多元醇、异氰酸酯、催化剂、发泡剂和阻燃剂等为原料制备了全水发泡阻燃聚氨酯硬质泡沫(PURF),讨论了聚醚多元醇种类、催化剂、发泡剂、异氰酸酯指数以及阻燃剂对PURF性能的影响。结果表明,聚酯多元醇能够改善泡孔结构,但降低压缩强度和尺寸稳定性;不同催化剂复配,可以控制发泡工艺;水发泡剂与泡沫的密度、泡孔结构、力学性能有关;异氰酸酯指数在1.1～1.2时,泡沫的压缩强度、尺寸稳定性等较好;三(2-氯异丙基)磷酸酯(TCPP)可赋予PURF一定的阻燃性,但对泡体结构、压缩强度和尺寸稳定性有影响。