改性小麦秸秆纤维对PBS复合材料性能的影响研究

采用NaOH对小麦秸秆纤维进行处理,在此基础上使用蒸煮助剂Na2S2O4和偶联剂(KH550、KH560)改性秸秆纤维,并将其分别与聚丁二酸丁二醇酯(PBS)共混,制备了秸秆纤维/PBS复合材料.研究了NaOH处理中Na2S2O4的添加以及NaOH处理后KH550、KH560的改性对复合材料性能的影响.采用EDS、WXRD和SEM对改性前后的纤维及复合材料分别进行了分析和观测.研究结果表明:NaOH同3％ Na2S2O4混合处理得到的复合材料的性能最好,KH560较KH550更能有效地改善复合材料的力学性能,当KH560质量分数为2％时,复合材料的力学性能最好.     

KH560改性氧化锆粉体及凝胶注模研究

采用硅烷偶联剂KH560对氧化锆粉体进行湿法改性,研究了硅烷偶联剂KH560添加量对凝胶注模成型氧化锆陶瓷性能(抗折强度、硬度和密度)及浆料性能的影响,并研究了添加量对氧化锆粉体、生坯和陶瓷显微结构的影响。结果表明:采用KH560改性氧化锆粉体可改善粉体团聚,烧结后获得高强度高致密性的氧化锆陶瓷。当KH560添加量为0.8 wt%,可获得悬浮性良好且粘度为425.7 mPa·s(固含量50%)的浆料,密度、气孔率、硬度和抗折强度分别为6.013 g/cm~3、0.019%、90±2.23 HRB和843.92 MPa的氧化锆陶瓷。通过SEM观察,改性后,氧化锆粉体团聚减少,生坯和陶瓷气孔、团聚减少,颗粒较改性前分布较为均匀,内部结构较为致密。     

硅烷偶联剂改性酚醛泡沫塑料的制备和性能研究

以硅烷偶联剂KH–560作为增韧剂,制备了KH–560改性酚醛泡沫塑料,研究了KH–560含量对酚醛泡沫塑料性能的影响。结果表明,添加KH–560制备的改性酚醛泡沫塑料的性能得到明显提高,当KH–560质量分数(相对于参加反应苯酚的质量)为7%时,改性酚醛泡沫塑料的压缩强度、冲击强度和阻燃性均达到最大值,同纯酚醛泡沫塑料相比,分别提高了37%,68%和3.8%。当KH–560质量分数为5%时,改性酚醛泡沫塑料的粉化率最小,为1.6%。热失重分析结果表明,改性酚醛泡沫的热稳定性仅稍有降低,500℃时的质量保持率较纯酚醛泡沫塑料提高1%~3%,仍然保持优良的热稳定性。     

硅烷偶联剂改性聚硅氧烷乳液的合成及性能研究

以γ-缩水甘油醚氧丙基三甲氧基硅烷(KH 560)、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH 570)及八甲基环四硅氧烷(D4)为原料,十二烷基苯磺酸(DBSA)阴离子乳化剂(又作催化剂)与烷基苯酚聚氧乙烯醚(OP-10)非离子乳化剂为复合乳化剂,通过乳液聚合反应合成了性能稳定的改性聚硅氧烷乳液。讨论了KH 560、KH 570及混合单体(KH 560/KH 570)用量对聚硅氧烷乳液粒径及性能的影响。结果表明:随着KH 560用量的增加,乳液粒径逐渐增大,而分布指数先减小后增大。随着KH570用量的增加,乳胶粒粒径先增大后减小,但是粒径分布变窄。两种改性单体同时加入所合成的乳液粒径更大。硅烷偶联剂改性聚硅氧烷乳液耐高温稳定性、耐低温稳定性、离心稳定性及稀释稳定性都良好。加入KH 560单体改性的聚硅氧烷乳液,其在环境温度下成膜效果较佳。     

PHA/粉煤灰复合材料的制备与性能分析

分别以γ-缩水甘油醚氧丙基三甲氧基硅烷(KH560)改性粉煤灰及未改性粉煤灰为填料,采用熔融共混法制备了聚羟基脂肪酸酯(PHA)基复合材料,并从微观形貌、物理力学性能、热力学性能等方面对上述复合体系进行了评价。结果表明:KH560的加入使PHA基体与粉煤灰之间发生反应,改善了二者的相容性;粉煤灰的加入对PHA材料起到增韧的作用;粉煤灰的添加可以改善PHA材料的热性能。     

KH560@ZnO掺杂淀粉复合材料的制备及其抑菌特性

采用γ-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH560)改性水热法制备纳米ZnO,然后通过熔融共混方式将其掺入淀粉基底,获得KH560@ZnO淀粉复合材料,研究复合材料组成、微观形貌,分子构造、光电特性及相应作用规律,初步探索复合材料抑制大肠杆菌的效果.结果表明,纳米ZnO粉体形貌均一,具有较高的结晶度,平均粒径约85 nm,KH560对纳米ZnO的接枝率为10.09％.进一步将改性纳米ZnO与淀粉基底键合连接,复合材料基本维持晶型构造,采用KH560对纳米ZnO改性提高了纳米ZnO在淀粉中的分散程度及稳定性.随着KH560@ZnO含量的增加,复合材料光致发光强度、紫外屏蔽性能和抑制大肠杆菌的能力提升,但透光率呈下降趋势.KH560@ZnO在淀粉材料中掺杂量为10％(以淀粉质量为基准,下同)时,复合材料对大肠杆菌的抑菌率约95％.     

硅烷偶联剂对PP/GNPs复合材料性能的影响

采用硅烷偶联剂KH550,KH560和KH570对石墨烯(GNPs)进行表面改性,通过预混、熔融共混、挤出制备了聚丙烯(PP)/改性GNPs复合材料,研究了3种硅烷偶联剂对PP/GNPs复合材料性能的影响.结果表明:与PP/GNPs相比,PP/改性GNPs复合材料的力学性能明显提升,KH560改性PP/GNPs复合材料...     

低介电常数聚酰亚胺/多金属氧酸盐复合薄膜的制备及其性能

以带环氧官能团的3-环氧丙氧基三甲基硅烷(KH560)作为改性剂在酸性MeCN/H2O混合溶液中和多金属氧酸盐K8SiW11O39进行反应,制得了硅烷改性的多金属氧酸盐有机杂化物SiW11KH560,红外光谱、XPS等分析结果表明KH560与K8SiW11O39发生了反应。将改性后的K8SiW11O39添加到均苯四甲酸酐-二苯醚二胺的聚酰胺酸溶液中,热酰亚胺化制备了聚酰亚胺/多金属氧酸盐复合薄膜。EDS能谱分析表明多金属氧酸盐颗粒在聚酰亚胺基体中呈均匀分布,当复合薄膜中多金属氧酸盐有机杂化物SiW11KH560含量达到20%(wt)时,复合薄膜的介电常数从3.29降低至2.9。此外,随着SiW11KH560添加量的增加,复合薄膜的储能模量也显著提高,而复合薄膜的热性能没有受到严重影响。     

KH560表面改性ATO纳米粉体的研究

以硅烷偶联剂KH560(γ-缩水甘油醚氧丙基三甲氧基硅烷)为表面改性剂,对ATO(锑掺杂氧化锡)纳米粉体进行表面接枝改性,制得KH560偶联改性的ATO纳米粉体。采用傅立叶变换红外光谱(FTIR)、热重分析(TG)、粒度分析等手段对其进行了分析和表征,研究了KH560用量、反应温度、反应时间对ATO纳米粉体表面偶联改性的影响。结果表明,在乙醇、水混合溶剂中可以实现KH-560对ATO纳米粉体的偶联改性,当KH560用量为0.4 ml,反应温度为30℃,反应时间为2 h时,ATO粉体表面接枝的KH560接枝率最大,并获得较好的分散性。     

水性硅溶胶-有机硅纳米杂化材料在陆水砂浆中的应用研究

将几种功能性有机硅烷偶联剂、含氢硅氧烷环状单体和含氢硅油与不同pH值的无机纳米硅溶胶水溶液反应制备出硅系有机-无机纳米杂化复合液和通过溶胶-凝胶法制出有机硅-硅溶胶杂化固体微粉,并用IR和TEM对杂化材料进行表征,研究了杂化复合液的稳定性和杂化复合液与杂化微粉中有机硅种类、杂化比和用量对水泥砂浆凝结硬化的影响和对聚合物改性水泥砂浆的强度和防水性能的影响.结果表明:(1)有机硅-硅溶胶杂化复合液对水泥砂浆有一定的缓凝作用;(2)改性砂浆的28d抗压强度都高于空白水泥砂浆的28d抗压强度.而且改性砂浆具有显著的防水功能;(3)杂化微粉改性水泥砂浆抗压强度接近于空白样,但吸水率较低,具有较佳的防水性能.     

聚苯乙烯接枝聚丙烯酸丁酯乳液改性水泥砂浆的性能及微观结构分析

合成了聚苯乙烯（PS）接枝聚丙烯酸丁酯（PBA）乳液（PS?g?PBA）,并将其用于改性水泥砂浆,考察了PS?g?PBA乳液含量及PS与PBA的质量比对改性水泥砂浆的减水率、流动度、力学性能以及毛细孔吸水率的影响。结果表明,3种水泥改性剂的减水效果优异,减水率的极大值为56.7 %,改性水泥砂浆的毛细孔吸水率下降明显,其极小值为0.288 kg/m²;PS?g?PBA乳液对改性水泥砂浆的力学性能也产生重要影响。使抗压强度普遍降低,部分改性砂浆的抗折强度增加,其极大值为8.1 MPa。经扫描电子显微镜观察到了乳胶膜与水泥水化物形成的互穿网络结构以及位于孔洞中正六角形板状的氢氧化钙的晶体结构。综上,PS?g?PBA乳液可以在水泥砂浆中应用。     

吐温⁃80对PB⁃g⁃PSG乳液改性水泥砂浆性能的影响及作用机理

以聚丁二烯（PB）接枝苯乙烯（St）和甲基丙烯酸环氧丙酯（GMA）为主要原料制备了水泥砂浆改性剂PB?g?PSG乳液,将吐温?80作为稳定剂加入至PB?g?PSG乳液,再将乳液与水泥、标准砂混合制备了改性水泥砂浆;通过扫描电子显微镜（SEM）、水泥胶砂流动度测定仪和激光粒度分析仪等仪器观察了改性水泥砂浆的微观形貌,并研究了吐温?80及PB?g?PSG乳液含量对改性水泥砂浆流动性、力学性能、保水率以及吸水性的影响,同时探讨了吐温?80对PB?g?PSG乳液的作用机理。结果表明,改性水泥砂浆的保水效果优异,保水率的最大值为99.3 %;改性水泥砂浆的吸水质量随吐温?80含量的增加先降后增;改性水泥砂浆的流动性增强,其抗压强度随PB?g?PSG乳液含量的增加而逐渐降低,且小于未改性的水泥砂浆,其抗折强度随PB?g?PSG乳液含量的增加先增后降,且基本高于未改性的水泥砂浆,当PB?g?PSG乳液含量为10 %（质量分数,下同）时,抗折强度最高,为9.52 MPa;PB?g?PSG乳液对水泥水化物具有黏合及桥接作用,二者能够形成互穿网络结构;吐温?80分子结构中的亲水基团能够将水吸附在PB?g?PSG乳液粒子的表面并形成一层很厚的水化层,使乳胶粒子之间被隔离而避免了凝聚的发生。     

Effect of gamma irradiation on polymer modified white sand cement mortar composites

This study focuses on the substitution effect of standard sand of cement mortar by different ratios of white sand to prepare white sand cement mortar. The prepared samples were first cured under tap water for different time intervals 3, 7, 28 and 90 days. The effect of addition of 10% styrene–acrylic ester as well as the effect of different doses of gamma rays on the physico-mechanical properties of polymer modified white sand cement mortar specimens also, discussed. Compression strength test, total porosity and water absorption percentages were measured. The results were confirmed by scanning electron microscopy, and thermogravimetric analysis studies.     

偶联剂改性氧化铈提高硅凝胶的耐热氧性能

针对硅凝胶在使用过程中发生的变硬变脆等老化问题,本文以乙烯基硅油为基胶,含氢硅油为交联剂,氧化铝为填料制备了相应的硅凝胶弹性体。通过热重分析和马弗炉等温失重确定了硅凝胶基胶的热氧老化方式和氧化铈的抗热氧老化性能,并用三种不同类型的偶联剂对氧化铈进行了表面改性,探究了偶联剂改性氧化铈对硅凝胶耐热氧老化性能的影响。结果表明,添加偶联剂改性氧化铈可以明显提高硅凝胶的耐热性能,250℃老化8天,添加1%（质量分数）纳米氧化铈硅凝胶的拉伸强度与老化前相比增加了7.8倍,与此同时,添加1%（质量分数）KH560、6121和7707型偶联剂改性氧化铈的硅凝胶拉伸强度分别增加了2.5倍、4倍和4.7倍。综上,在老化前期,添加KH560偶联剂改性氧化铈的硅凝胶力学性能变化最小,抗热氧老化性能最佳。     

A ultra-low viscosity stearic acid emulsion prepared by lauric acid as waterproof agent for cement mortar

Safe building structures cannot be achieved without reliable waterproofing engineering. To address the susceptibility of concrete materials to water leakage, a low-viscosity stearic acid emulsion has been developed as a waterproofing agent for mortar. By introducing lauric acid, the formation of stearic acid crystals in water could be effectively prevented, resulting in a stearic acid emulsion with a viscosity of only 24 mPa·s. It is found that the best overall performance was achieved when the ratio (R) of lauric acid to stearic acid was 2/3. This emulsion has the least effect on mortar fluidity and setting time. The as-prepared modified mortar possessed the highest compressive strength (127% of the blank) and the lowest water absorption at 48 h (37% of the blank). X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive x-ray spectroscopy (EDS), scanning electron microscopy (SEM), dynamic light scattering (DLS) particle size analysis, and water contact angle measurements were used to investigate the mechanism of stearic acid emulsion's modification. It is determined that the stearic acid emulsions successfully modified the internal and external hydrophobicity of the mortar by chemical action with calcium hydroxide.     

纳米SiO2/OTAC协同稳定Pickering乳液聚合制备水基硅橡胶

以十八烷基三甲基氯化铵(OTAC)协同纳米SiO₂制备Pickering乳液,碱性条件下引发D₄开环聚合制备线性聚硅氧烷(PDMS),然后加入交联剂KH560制备阳离子型水基硅橡胶乳液。考察了纳米SiO₂与OTAC用量对Pickering乳液性能的影响,通过zeta电位、TEM及SEM研究了OTAC在SiO₂表面的吸附状态,用FT-IR、²⁹Si NMR对水基硅橡胶的结构进行了表征,研究了KH560用量对橡胶膜对水接触角和邵氏硬度的影响。结果表明: w(SiO₂)=2.0%时,乳液流动性和稳定性最优;w(OTAC) = 1.75%时,OTAC在纳米SiO₂表面的单层吸附达到饱和,单体转化率为89%,粒径为617 nm,zeta电位接近零点,PDMS的数均分子量为16036,PDI为1.485;w(KH560)=5.0%时,KH560与PDMS充分水解缩合,硅橡胶膜憎水性和硬度显著提高。     

Nano-SiO_2/PU胶黏剂的制备及性能研究

文章采用硅烷偶联剂(KH550、KH560和KH570)改性纳米SiO2,并利用超声设备将其分散在聚醚二醇中,再加入TDI进行预聚反应,得到-NCO封端的预聚体。利用二乙烯三胺扩链得到A组分,加入固化剂B组分,制得醇溶型纳米SiO2/PU胶黏剂。并对改性后的胶黏剂进行了微观结构分析和性能测试。测试结果表明:经偶联剂改性后的纳米SiO2能够与聚氨酯达到很好的纳米尺度的复合,且掺杂SiO2后的聚氨酯胶黏剂剪切强度和耐水性进一步提高。     

浅谈预拌砂浆对水泥的评价与选择

通过两种不同水泥配制成干混砂浆的性能对比,研究了水泥对砂浆保水性、稠度、2 h稠度损失、分层度、含气量、凝结时间、黏聚性、流动度、强度等性能的影响。结果表明:水泥细度对砂浆稠度、分层度、含气量有明显影响;水泥混合材种类与掺加量影响砂浆的保水性、黏聚性;水泥熟料矿物组成影响砂浆保水性;水泥凝结时间影响砂浆凝结时间、2h稠度损失等。而且这些影响不是孤立的,每个水泥参数可能对砂浆多种性能产生作用,故建议水泥生产应根据砂浆需求提供个性化的产品;砂浆企业应根据砂浆品种和施工条件选择合适的水泥品种。     

Mechanism and properties of coloured nanoscale SiO2 prepared from silica and reactive dyes

KH560‐modified SiO₂ was prepared using tetraethyl orthosilicate (TEOS) and γ‐(2,3‐epoxypropoxy) propytrimethoxysilane (KH560) by the sol–gel method and then coloured with CI Reactive Blue 4 (X‐BR) to prepare coloured nanoscale SiO₂. The antisolvent performance and the results of cross‐polarisation/magic angle spinning ¹³C nuclear magnetic resonance and Fourier transform infrared spectroscopy showed that the reaction of X‐BR with KH560‐modified SiO₂ is a two‐step process: X‐BR is firstly adsorbed by KH560‐modified SiO₂ via van der Waals forces, and then nucleophilic substitution occurs between dichloro triazine and the epoxy group. The grafting ratio of X‐BR on KH560‐modified SiO₂ reached 95% under optimum conditions, i.e. a mass ratio of KH560 to TEOS of 20%, a temperature of 40 °C, a pH of 8.5, and a reaction time of 5 h. X‐ray diffraction analysis and transmission electron microscopy showed that the coloured nanoscale SiO₂ was amorphous, with a mean diameter of 216 nm. Experimental application showed that the coloured nanoscale SiO₂ had excellent stability to solvents and alkaline solution, and the absorptive capacity of the coloured nanoscale SiO₂ in the 200–400 nm region was higher than that of X‐BR. The light fastness of the coloured nanoscale SiO₂ reached 5–6 grade.     

Preparation and properties of modified graphene oxide incorporated waterborne polyurethane acrylate

In this study, a new modifier (KPG) was prepared by modifying graphene oxide with γ‐glycidoxypropyl trimethoxysilane (KH560) and polydimethylsiloxane (PDMS). KPG was in turn added to aqueous urethane acrylate for the fabrication of waterborne polyurethane polyacrylate emulsion modified with KH560‐PDMS composite (KPG/WPUA). Textural characterizations of the KPG/WPUA coating were achieved via Fourier transform infrared, SEM, TGA and AFM techniques, which revealed that the KPG/WPUA film possessed a smooth surface. The synthesized KPG/WPUA films were tested for mechanical properties, hydrophobicity and acid/water corrosion performance which suggested their highly hydrophobic surface. KPG/WPUA with 0.1% KPG showed a contact angle of 118.35°, 30.35° higher than that of pristine WPUA. The KPG/WPUA film exhibited higher thermal stability, i.e. a 5% weight loss temperature of 305 °C, which was 30 °C higher than that of pristine WPUA film. The Young's modulus and elongation at break of the KPG/WPUA film were 34.1 MPa and 74.88% respectively, which were higher than that of WPUA film. Furthermore, KPG/WPUA films exhibited greater resistance (without obvious blistering and the white spotting phenomenon) to H₂O₂, HCl and water corrosion than pristine WPUA. The superior performance of KPG/WPUA films was attributed to the network chain structure formed upon the introduction of KPG into WPUA. The outstanding performance of KPG/WPUA films in terms of mechanical properties, thermal stability and high resistance to acidic and water corrosion makes them interesting alternative contenders for target applications. © 2019 Society of Chemical Industry