PU/MOMMT纳米复合材料的制备与研究

纳米复合材料由于其纳米尺寸效应，表面效应以及纳米粒子与基体界面间强的相互作用，具有优于相同组分常规复合材料的力学、热学等性能，引起了人们的广泛关注。用纳米材料改性聚合物，制备纳米复合材料是获得高性能高分子复合材料的重要方法。1998年以来，Pinnavaia等首先制备了聚氨酯，蒙脱土（PU／MMT）纳米复合材料，研究了有机蒙脱土在聚醚中的分散性。其后Chen等将聚羟基己内酯/蒙脱土（PCL／MMT）纳米复合材料加入到PCL和二苯基甲烷-4，4＇-二异氰酸酯（MDI）合成的预聚体与1，4-丁二醇扩链反应后的溶液中，制备了PU／MMT纳米复合材料。少量PCL／MMT的引入可使复合材料的综合性能大幅提高。     

不饱和聚酯／聚氨酯复合体系的研究

以端羟基不饱和聚酯（ＨＵＰ）与聚氨酯（ＰＵ）浇注型复合网络聚合物（ＣＰＮｓ）为基材，考察了化学动力学及相分离对ＣＰＮ聚合物物理机械性能的影响．数据揭示了不饱和聚酯／聚附聚氨酯（ＨＵＰ／ＰＵ－ｅｓ）ＣＰＮ，当ｒ＝ＮＣＯ／ＯＨ＝０．４时，它的物理力学性能优于不饱和聚酯／聚醚聚氨酯（ＨＵＰ／ＰＵ－ｅｔ）ＣＰＮ或ＨＵＰ／ＰＡＰＩＣＰＮ组成物．最佳ＣＰＮ可通过调整聚氨酯中软段和硬段组分及网络组成而设计与制备．     

插层聚合制备聚丙烯/蒙脱土纳米复合材料及其结构性能表征

将插层聚合的概念引入烯烃聚合,制备了聚丙烯／蒙脱土（PP／MMT）纳米复合材料。X射线衍射和TEM分析结果表明,蒙脱土在聚丙烯基体中达到了纳米级的分散,动态力学性能研究结果表明,在高于Tg的温度区域内PP／MMT纳米复合材料的储能模量（E′）成倍增加,加入8％的蒙脱土（MMT）,PP／MMT的E′提高近3倍。PP／MMT的玻璃化转变温度Tg有一定程度的提高,随蒙脱土含量的增加,PP／MMT的热分解温度和热变形温度（HDT）都有大幅度提高。     

马来酸酐接枝ABS对木粉/ABS复合材料性能的影响

采用压延-模压工艺制备木粉/丙烯腈-丁二烯-苯乙烯(ABS)复合材料,考察了相容剂马来酸酐接枝ABS(ABS-g-MAH)用量对木粉/ABS复合材料性能的影响。结果表明,相容剂ABS-g-MAH可有效改善木粉/ABS木塑复合材料的界面相容性,提高复合材料的力学性能、热分解温度和加工流动性,在ABS-g-MAH含量为8%(wt)时,复合材料力学性能达到最佳、材料的界面粘附性最好,但相容剂ABS-g-MAH的加入对复合材料的抗蠕变性没有改善作用。     

接枝和交联对纳米Si02改性NR／PP共混型热塑弹性体的影响

动态硫化制备纳米二氧化硅（SiO2）改性天然橡胶，聚丙烯共混型热塑性弹性体（NR/PPTPE）．研究了马来酸酐，苯乙烯，过氧化二异丙苯（MAH／St／DCP）多单体“就地”熔融接枝、交联对TPE力学性能、耐溶剂性能和耐热变形性能的影响，并用SEM分析了TPE的断面形貌．结果表明：纳米SiO2和MAH／St／DCP的最佳质量分数分别为0．03和0．0375／0．0188／0．00375时，MAH／St／DCP接枝、交联改性NR／PP／纳米SiO：TPE的力学性能、耐溶剂性能和耐热变形性能最佳．MAH／St／DCP“就地”接枝、交联通过细化交联NR分散相、改善交联NR分散的均匀性和增加两相之间的共交联，使NR与PP两相界面结合强度明显提高，NR／PPTPE的综合性能得到明显的改善．     

聚甲基乙撑碳酸酯/氧化石墨烯纳米复合材料的制备及性能研究

本文采用改进Hummers法制备氧化石墨烯(GO),通过原子力显微镜对GO片层形貌进行表征;以聚甲基乙撑碳酸酯(PPC)、聚乙烯醇(PVA)和氧化石墨烯(GO)为原料,采用溶液和熔融共混法相结合,制备PPC/PVA/GO纳米复合材料,研究其力学性能、热学性能和动态流变行为。结果表明,当GO含量为0.5 wt%时,拉伸强度达到了22.03 MPa,与纯PPC相比提高了25.8%;当GO含量增大到1.0 wt%时,拉伸强度开始降低;断裂伸长率随GO的加入呈现降低的趋势。GO含量为1.0%时复合材料的热学性能最好,与纯PPC相比,复合材料的完全热分解温度从350℃提高到了400℃以上,并且热分解速率下降了12%/min;复合材料的复数黏度、储能模量和损耗模量随PVA及GO的引入也有一定程度的提高。     

β-羟基丁酸与β-羟基戊酸共聚物 (PHBV)/蒙脱土纳米复合材料的结构与性能

用溶液复合法成功地制备了插层型PHBV／蒙脱土纳米复合材料。采用X射线衍射（XRD）和透射电子显微镜（TEM）研究了复合材料的结构，硅酸盐片层间距从1.8nm升至2.4nm左右。同时研究了复合材料的结晶，熔融，动态力学行为和力学性能，发现有机蒙脱土的加入，可以加快PHBV的结晶,降低熔融温度，使基体的玻璃化转变温度升高，提高了材料的力学性能，有机蒙脱土含量在3％时，其综合性能最佳。     

累托石/聚丙烯插层纳米复合材料的制备与性能

采用熔融共混法制备了有机改性累托石 (OREC)粘土 均聚聚丙烯 (PP)纳米复合材料 ,以X 射线衍射分析 (XRD)及透射电子显微镜分析 (TEM)观察了复合材料的相貌结构 ,研究了复合材料的力学性能及热性能 .结果表明 ,OREC在添加份数较少时可与均聚聚丙烯熔融插层形成插层型聚丙烯纳米复合材料 ,该复合材料与纯PP相比 ,具有较高的拉伸强度、断裂伸长率及冲击强度 .在有机粘土添加 2 %时 ,复合材料的拉伸强度、断裂伸长率、冲击强度最高 ,与纯PP相比 ,2 %添加量的聚丙烯纳米复合材料拉伸强度提高 6 5 7% ,断裂伸长率提高 2 89 3% ,冲击强度提高 14 1% ,10 %失重率时对应的热分解温度提高 50K .     

PC/ABS及PC/ABS/PE-g-MAH共混体系相容性的研究

研究了聚碳酸酯与ＡＢＳ（ＰＣ／ＡＢＳ）及ＰＣ／ＡＢＳ与马来酸酐接枝聚乙烯共聚物（ＰＣ／ＡＢＳ／ＰＥ－ｇ－ＭＡＨ）共混体系的力学性能和应力开裂性能。用ＤＳＣ和ＳＥＭ研究了共混体系的相容性。结果表明：ＡＢＳ的加入能提高ＰＣ的冲击强度,ＡＢＳ的含量及品种影响ＰＣ／ＡＢＳ合金的力学性能,ＡＢＳ能提高ＰＣ的耐溶剂应力开裂性能。ＰＣ／ＡＢＳ／ＰＥ－ｇ－ＭＡＨ共混体系的力学性能和相容性优于ＰＣ／ＡＢＳ共混体系,     

界面缩聚法合成双酚A芳香环状聚醚砜

聚芳醚（酮、砜）是一类耐高温、耐溶剂的高性能的聚合材料,具有很好的机械和加工性能,广泛应用于工程塑料及复合材料等领域．线性聚芳醚（酮,砜）一般由亲核取代反应或亲电取代反应在极性溶剂中制得,Ｙｏｓｈｉｏ等［１］报道利用相转移催化法制备聚芳醚砜,近年来,...     

Mechanical properties of rigid polyurethane composites reinforced with surface treated ultrahigh molecular weight polyethylene fibers

The mechanical properties of ultrahigh molecular weight polyethylene (UHMWPE) fibers reinforced rigid polyurethane (PU) composites were studied, and the effects of the fiber surface treatment and the mass fraction were discussed. Chromic acid was used to treat the UHMWPE fibers, and polyurethane composites were prepared with 0.1 to 0.6 wt% as‐received and treated UHMWPE fibers. Attenuated total reflection Fourier transform infrared demonstrated that oxygen‐containing functional groups were efficiently grafted to the fiber surface. The mechanical performance tests of the UHMWPE fibers/PU composites were conducted, and the results revealed that the treated UHMWPE fibers/PU composites had better tensile, compression, and bending properties than as‐received UHMWPE fibers/PU composites. Thermal gravimetric analyzer showed that the thermal stability of the treated fiber composites were improved. The interface bonding of PU composites were investigated by scanning electron microscopy and dynamic mechanical analysis, and the results indicated that the surface modification of UHMWPE fiber could improve the interaction between fiber and PU, which played a positive role in mechanical properties of composites.     

聚吡咯/多壁碳纳米管及其聚氨酯导电复合材料的制备和性能

以羧基化多壁碳纳米管(MWCNTs)做模版剂,采用化学氧化法将吡咯(Py)在羧基化MWCNTs表面聚合制备PPy/MWCNTs导电材料,将其添加到溶剂型聚氨酯(PU)溶液中制备了PPy/MWCNTs/PU导电复合材料,研究了Py用量对PPy/MWCNTs及其PU复合材料性能的影响.研究表明,随Py用量的增加,PPy/MWCNTs的长度不变,管径增大,sp~2和sp~3杂化C含量先提高后减少,N的掺杂梯度降低,PPy/MWCNTs的导电率高于羧基化MWCNTs和PPy.当Py用量为羧基化MWCNTs的20%时,其导电率最大.PPy/MWCNTs中N元素的掺杂程度及其管径变化是引起PPy/MWCNTs/PU复合材料的性能不同的主要原因.增加Py用量,MWCNTs中亲水的羧基因对PPy掺杂而消耗,相同导电材料用量时纳米导电粒子数目相对减少,PPy/MWCNTs/PU复合材料的耐水性能提高,定向应力、储能模量和玻璃化温度降低,导电率先增加后减小.当Py用量为羧基化MWCNTs的15%时,导电率最大.     

改性纳米炭黑/聚氨酯复合物的制备及表征

利用有机硅偶联剂改性的纳米炭黑和聚氨酯制备了纳米炭黑/聚氨酯复合物. 采用红外光谱、透射电镜、流变学及力学性能等测试方法对纳米粒子及其聚氨酯复合物进行了表征. 红外光谱表明, 纳米粒子的存在使聚氨酯的氢键结构发生了改变. 适量改性纳米炭黑粒子明显提高了聚氨酯的拉伸强度和断裂伸长率等力学性能. 流变学测试结果表明, 溶液中改性纳米炭黑粒子与聚氨酯分子间存在明显的相互作用.     

EP-g-PU IPN结构阻尼材料

采用-NCO封端的聚氧酯(PU)预聚物,制备了环氧树脂-聚氨酯互穿网络(EP-g-PU IPN);通过添加受阻酚四[β-(3,5-二叔丁基-4-羟基苯基)丙酸]季戊四醇(AO-60)制备了AO-60/EP-g-PU IPN.通过FT-IR、DMA、SEM分别研究了改性分子链的基团变化、改性体系的动态性能及断裂面的形态,...     

微波处理和溶胶凝胶法共同改性废胶粉及其与天然橡胶复合材料性能的研究

采用微波处理打断废胶粉(WRP)的三维网状结构用来提高WRP在有机溶剂中的溶胀性,然后采用溶胶凝胶法,将微波改性后的WRP浸入正硅酸乙酯中,通过水解反应和缩合反应,在WRP表面原位生成SiO2网络,从而制得改性废胶粉(MWRP).将制得MWRP与天然橡胶(NR)共混,制备了NR/MWRP复合材料,研究了NR/MWRP复合材料的性能.通过热重分析仪、差示扫描量热仪和力学分析表明微波处理最佳时间是20 s.由于微波处理提高了NR与WRP的相容性,原位生成的SiO2粒子起到了补强作用,所以所制备的NR/MWRP复合材料拥有较好的力学性能;随着Si69的加入,抑制了SiO2粒子聚集,提高了SiO2粒子的分散性,从而进一步提高复合材料的力学性能并降低复合材料的Payne效应;在进行频率扫描时,硫化胶的储存模量随频率的增大而增大;硫化胶的温度扫描结果表明,随着温度的升高,复合材料中SiO2粒子聚集程度加剧并且复合材料出现老化的现象.为了提高复合材料的耐老化性能,N,N-间苯撑双马来酰亚胺(BMI)作为一种防老剂加入复合材料中,BMI利用Diels-Aider反应补偿橡胶在老化过程中所损失的交联键并提高NR与WRP的界面相容性,从而提高复合材料的耐老化性能.     

Modification of the rheological properties of polyurethanes by adding fumed silica: influence of the preparation procedure

The way of addition of fumed silica determined the rheological properties of polyurethane (PU) adhesives. The higher the shear rate during preparation of fumed silica containingPU adhesives, the higher viscosity and improved plasticity and thixotropy in the solutions. The improved properties of these adhesive solutions were ascribed to the creation of interactions between the silanol groups on the fumed silica, the polar groups in the soft segments of the polyurethane and/or the solvent. However, the way of incorporate the fumed silica in the polyurethane did not affect the rheological properties of fumed silica-PU composites (obtained by solvent removal from the solutions), indicating the key role of the solvent in the rheology of PU adhesive solutions.     

Effect of filler shape on mechanical properties of rigid polyurethane composites containing plant particles

The effect of types of fillers on mechanical properties of rigid polyurethane composite samples was investigated. Polyurethane (PU) composites were prepared using a molasses polyol (MP, a mixture of molasses and polyethylene glycol, Mw=200) diphenylmethane diisocyanate (MDI) and fillers. The following plant particles, bamboo powder, roast bamboo powder, wood meal, coffee grounds, ground coffee bean parchment and cellulose powder, were used as fillers. The mixture of MP and fillers was reacted with MDI by adding an adequate amount of acetone as a solvent. The content of fillers was defined as the ratio of filler weight to total weight of polyol and fillers. The filler content was varied from 10 to 90 wt%. Polyurethane (PU) composites were prepared using fillers with MP. Lengths of major axis and minor axis for each particle regarded as an ellipse were measured using an optical microscope. Averages of diameter and aspect ratio were derived for each plant particle. The relationships between these average values and the mechanical properties, such as strength and elastic modulus, determined by the compression tests were investigated. The effect of filler content was estimated using the apparent volume ratio which is determined as the ratio of the apparent volume of fillers to the reciprocal values of the apparent density of samples. The master curves of the relationships between the specific values of mechanical properties and the apparent volume ratio were obtained. It was found that the compression strength and the elastic modulus for composite samples with different fillers showed maximum values at average aspect ratio around 3. It was also found that the apparent volume ratio, where the mechanical properties showed maximums, decreases with increasing aspect ratio. Using master curves, it is possible to evaluate the mechanical properties of plant particle filled polyurethane composites are described.     

Thermogravimetry on wood powder-filled polyurethane composites derived from lignin

Novel polyurethane (PU) composites whose matrix is derived from lignin, molasses polyol and filler from wood powder were successfully prepared. Two kinds of polyol were mixed 0/100 to 100/0 in seven steps, and filler content was varied from 50 to 100 mass % to polyol content. Decomposition behaviour of PU composites was investigated by thermogravimetry. Apparent density and mechanical properties of the above composites were also measured. Surface texture was observed by scanning electron microscopy. Thermal decomposition of PU composites was found to occur in two stages. The first decomposition observed at 570–580 K (DT _d1, peak temperature of derivative curve) is attributed to the matrix of composites. The second stage decomposition depending on filler content, observed in a temperature range from 590 to 630 K (DT _d2), is attributable to filler homogenously associated with PU matrix. Marked differences were not found, when the kinds of lignin and molasses polyol composition were varied. The above PU composites were found to be thermally stabilised by the introduction of filler.     

Dielectric properties and molecular mobility of organic/inorganic polymer composites

Microstructure-dielectric properties relationship and molecular mobility of organic/inorganic polymer composites (OIPCs), consisting of polyurethane (PU) and sodium silicate (NaSi), were investigated in this work. Broadband dielectric relaxation spectroscopy (DRS) and thermally stimulated depolarization current (TSDC) techniques were employed. Our interest was focused on the study of the glass transition mechanism and conductivity relaxation. The influence of the molecular weight of PU and inorganic phase content on the dielectric properties of the composites was of particular interest. Glass transition temperature shifts to higher temperatures with the addition of NaSi. The overall molecular mobility was found to increase in the composites, compared to the pure PU matrix. The results are more intense for the composites based on the PU with low molecular weight.     

Mechanical and electrical response variation of the polyurethane–tin oxide–carbon nanotube composite microfiber depending on the chemical solution

Toward the goal of smart sensor systems for wearable electronics, polymer microfiber‐based free‐standing sensors benefit from excellent flexibility, decent ductility, and easy wearability in comparison with thin‐film‐based sensing devices. Herein, we report a hydrophobic and conducting single‐strand microfiber‐based liquid‐phase chemical sensor consisting of polyurethane (PU), tin oxide (SnO₂), and carbon nanotube (CNT) composites with applying a (1H,1H,2H,2H‐heptadecafluorodec‐1‐yl) phosphonic acid (HDF‐PA)‐based self‐assembled monolayer. The free‐standing HDF‐PA‐treated PU–SnO₂–CNT composite microfiber showing selective filtering properties with the repellency of water and the penetration of an organic solvent is electrically and mechanically characterized. Finally, the single‐strand HDF‐PA‐treated PU–SnO₂–CNT composite microfiber‐based chemical sensor, which shows excellent mechanical properties and aqueous stability, is demonstrated to detect the presence of a chemical in pure water or counterfeit gasoline in pure gasoline by observing mechanical changes, especially variations in the length and diameter of the fiber, and monitoring the electrical resistance change. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019 , 57, 495–502