MWCNTs/有机硅改性丙烯酸酯纳米涂料的制备及性能研究

以有机硅改性丙烯酸酯乳液为基体,经KH-570表面改性处理的多壁碳纳米管(MWCNTs)为功能性填料,制备了MWCNTs/有机硅改性丙烯酸酯纳米涂料。通过不同的表征测试手段研究了纳米涂料的导热、耐酸碱腐蚀和附着力等性能。研究结果表明:改性MWCNTs的添加可显著改善纳米涂料的导热和耐酸碱腐蚀性能,同时使其保持优良的铅笔硬度和附着力;当w(改性MWCNTs)=4.0%(相对涂料总质量而言)时,涂膜的导热、耐酸碱腐蚀和力学性能均较佳。     

基于原位聚合法水性聚氨酯/MWCNTs杂化电沉积树脂的制备、形态及性能

采用超声波辅助反应技术,通过甲苯二异氰酸酯(TDI)改性羟基多壁碳纳米管(MWCNTs),制备出异氰酸酯修饰的活性MWCNTs。采用原位聚合法制备出MWCNTs杂化的水性聚氨酯树脂,与交联剂混合后得到水性聚氨酯电沉积涂料。采用红外光谱(FT-IR)、透射电子显微镜(TEM)、电导率仪等测试方法,研究了MWCNTs用量对水性聚氨酯漆膜外观和性能的影响。结果表明,MWCNTs成功接枝到聚氨酯分子主链上;随着MWCNTs用量的增加,水性聚氨酯漆膜的导电性、光泽度、硬度和耐酸性表现出先增大后降低的规律。当MWCNTs的质量分数为0.75%时,MWCNTs在水性聚氨酯树脂中表现出最好的分散稳定性,漆膜的导电性、光泽度、硬度和耐酸性等性能达到最佳。     

碳纳米管的表面修饰及其对环氧树脂热性能的影响研究

先后利用Fenton试剂和缩水甘油氧丙基硅烷偶联剂(KH560)对碳纳米管（CNTs）进行表面修饰,制备了不同种类的环氧树脂(EP)/CNTs复合材料并对其性能进行了研究。结果表明：CNTs经过Fenton试剂处理后,其表面成功引入羟基,进一步用KH560修饰后成功地引入了环氧基官能团。Fenton试剂的组成可以有效控制羟基基团的数目,并进一步决定环氧基官能团的数目。单独采用Fenton试剂处理或Fenton试剂和KH560共同处理都可以改善CNTs的分散性能,提高EP/CNTs复合材料的玻璃化温度（Tg）和热稳定性能,但后者的处理效果更好。     

催化剂Pt-Ag/PEDOT/MWCNTs的制备

采用两步还原的方法,分别使用硼氢化钠和乙二醇作为还原剂在修饰了的聚乙撑二氧噻吩(PEDOT)的多壁碳纳米管(MWCNTs)上制备了Pt-Ag/PEDOT/MWCNTs复合催化剂。采用扫描电镜(SEM)、能谱分析(EDX)、电化学测试等手段对样品进行表征,结果显示:PEDOT能够成功在碳纳米管表面修饰,且Ag和Pt在其表面分布均匀。     

玻璃纤维浸润剂的制备与性能

通过玻璃纤维浸润剂的制备,采用浸润剂中的硅烷偶联剂(KH550)进行接枝改性,并对二氧化硅进行接枝改性,探讨了制备浸润剂乳液的工艺条件等。分析了硅烷偶联剂的改性效果,制成的浸润剂乳液的性能,还分析了制备的浸润剂涂覆到玻璃纤维表面后得到的玻璃纤维的力学性能等。FT-IR测试结果表明,烯丙基聚氧乙烯聚氧丙烯环氧基醚(AEPH)已接枝到硅烷偶联剂上,硅烷偶联剂(KH550)接枝到二氧化硅上。接触角测试结果表明,二氧化硅的疏水性得到了明显改善。将改性后的硅烷偶联剂和二氧化硅加入到双酚A环氧乙烯基树脂为主成膜剂的乳液中,通过对乳液进行粒径、表面张力测试,结果表明:制备的乳液达到预期的要求。将乳液涂覆到玻璃纤维后,扫描电镜结果表明:浸润剂涂覆到了玻璃纤维表面上,且含1%改性硅烷偶联剂浸润剂比含0. 5%改性硅烷偶联剂浸润剂的涂覆厚度大。力学性能结果表明,浸润剂涂覆后,玻璃纤维的拉伸强度明显提高。     

醋酸乙烯-乙烯乳液用于低气味环境友好高性能涂料

介绍了醋酸乙烯-乙烯(VAE)乳液的技术基础,如VAE乳液的发展、合成技术、化学结构及性能优点。重点研究了在低VOC和低气味的环境友好内墙涂料中,VAE乳液与醋丙乳液、苯丙乳液对涂料性能的影响。结果表明:VAE乳液制备的涂料相对于使用低成膜温度的醋丙乳液涂料,具有更好的低温成膜性能和耐洗刷性能,并且在低PVC(颜料体积浓度)的涂料中具有更好的弹性;VAE乳液制备的涂料相对于低成膜温度的苯丙乳液,具有更好的对比率、低温成膜性和耐洗刷性。电子鼻分析仪的测试结果表明,VAE乳液制备的涂料比使用低气味苯丙乳液制备的涂料气味更低。     

不同成膜树脂对水性膨胀型防火涂料性能的影响

采用苯丙乳液、环氧乳液、硅丙乳液以及丙烯酸乳液为成膜物制备了几种膨胀型防火涂料,通过锥形量热仪(CONE)和小室法等手段对其防火性能进行研究,并对其理化性能进行了常规测试分析。研究结果表明:硅丙乳液涂料具有较好的防火性能,但其发泡层结构不够致密。若用硅丙乳液与环氧乳液按质量比1∶1复配后,可改善其防火涂料的发泡层结构,使其防火性能大大提高。     

有机改性海泡石/天然胶乳复合胶膜的制备及性能

采用硅烷偶联剂KH 550对酸处理后的海泡石进行表面修饰,并与天然胶乳进行乳液共混,制备了有机改性海泡石/天然胶乳复合胶膜。研究了有机改性海泡石的用量对复合胶膜的力学性能及热稳定性的影响。结果表明,偶联剂KH 550可与海泡石表面的羟基反应接枝到海泡石表面。随着有机改性海泡石用量的增加,有机改性海泡石/天然胶乳复合胶膜的500%定伸应力增大,拉伸强度、撕裂强度以及扯断伸长率先增加后减小。当有机改性海泡石的用量为2份时,复合胶膜具有良好的热稳定性。     

硅烷偶联剂对Nano-ZnO/PLA复合材料抑菌性能与热降解性的影响

采用硅烷偶联剂KH550对纳米氧化锌(nano-ZnO)进行表面处理,制备nano-ZnO/PLA复合材料,研究KH550和nano-ZnO对PLA材料的力学性能、抑菌性和热稳定性能的影响。用OFW方法分析材料的热降解行为。结果表明:nano-ZnO/PLA复合材料对大肠杆菌有抑菌性能。KH550表面处理提高nano-ZnO的分散性,增强其抑菌作用,改善复合材料的界面相容性,提高力学性能。nano-ZnO降低了PLA的热分解温度和热降解活化能,KH550延缓了这种作用。     

多壁碳纳米管表面羧基化及其阻燃ABS的性能

采用硝酸氧化/低温等离子处理两步法,将多壁碳纳米管(MWCNTs)羧基化(MWCNTs-COOH),以改善其在ABS基体中的分散性。通过熔融共混的方法制备不同组分ABS/MWCNTs-COOH复合材料。利用红外、拉曼分析、扫描电镜对改性修饰后MWCNTs结构进行研究;利用扫描电镜、热重分析、极限氧指数、残炭分析、力学性能测试对ABS/MWCNTs-COOH复合材料分散性、热性能、阻燃性能、力学性能进行研究。实验结果表明,MWCNTs羧基化改性后提高了在ABS基体材料中的分散性;当MWCNTs-COOH含量为1%时,复合材料初始分解温度和最大分解温度分别提高了22.69℃和27.90℃,热稳定性提高,同时复合材料力学性能也得到改善,拉伸强度提高了18.3%;极限氧指数和残炭测试表明,MWCNTs-COOH加入提高了复合材料的极限氧指数,MWCNTs-COOH在复合材料燃烧过程中,会在材料表面形成网络状炭层,提高复合材料的阻燃性能。     

无皂PVA接枝苯丙共聚乳液的制备

以聚乙烯醇(PVA)为主链,通过接枝丙烯酸(AA)、苯乙烯(St)和丙烯酸丁酯(BA)等单体,制备出一种无皂PVA接枝苯丙乳液。采用单因素分析法优选出制备PVA接枝苯丙乳液的较佳条件。结果表明:当w(引发剂)=2.5%、引发剂的滴加时间为3 h、反应温度为80℃、w(AA)=3%和反应结束后pH值为7时,乳液的聚合稳定性相对最好,其平均粒径(或粒径分布)小于(或窄于)核/壳型苯丙乳液。     

有机硅表面活性剂在苯丙乳液合成中的应用

通过硅氢加成反应合成了有机硅表面活性剂(PSS),将其用作非离子型乳化剂,采用半连续预乳化聚合法制备了苯丙乳液。采用红外光谱和能谱分析对PSS进行结构表征,并测出其CMC为4.53×10-6 mol/L,浊点61～62℃。考察了PSS用量(即其质量占单体质量的百分数,1%～5%)对苯丙乳液性能的影响。结果表明:当w(PSS)=4%时,乳液聚合单体转化率可达98.65%,凝胶率降至0.87%,制成的苯丙乳液乳胶膜吸水率降至9.51%,消泡时间为18 s,比非硅乳化剂(烷基酚聚氧乙烯醚,OP-10)制成的苯丙乳液表面张力低,消泡时间短,乳胶膜吸水率低、拒水性好。     

A novel hydrazine electrochemical sensor based on a carbon nanotube-wired ZnO nanoflower-modified electrode

ZnO nanoflowers were synthesized by a simple process (ammonia-evaporation-induced synthetic method) and were applied to the hydrazine electrochemical sensor. The prepared material was characterized by means of scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) and was then immobilized onto the surface of a glassy carbon electrode (GCE) via multi-walled carbon nanotubes (MWCNTs) to obtain ZnO/MWCNTs/GCE. The potential utility of the constructed electrodes was demonstrated by applying them to the analytical determination of hydrazine concentration. An optimized limit of detection of 0.18 μM was obtained at a signal-to-noise ratio of 3 and with a fast response time (within 3 s). Additionally, the ZnO/MWCNTs/GCE exhibited a wide linear range from 0.6 to 250 μM and higher sensitivity for hydrazine than did the ZnO modified electrode without immobilization of MWCNTs.     

水泥改性型苯乙烯-丙烯酸酯共聚乳液的合成工艺研究

为开发性能优良、价格低廉的苯乙烯-丙烯酸酯共聚乳液型水泥外加剂,着重讨论了以丙烯酸酯类和苯乙烯为主要原料、采用预乳化和半连续工艺合成水泥改性型苯乙烯-丙烯酸酯共聚乳液的方法,研究确定了丙烯酸酯类共聚乳液合成的配方设计及单体、乳化剂、引发剂、链转移剂等组分对制备所得的共聚物乳液结果的影响.在丙烯酸用量为单体总量的4%,阴、非离子乳化剂复配使用,乳化剂的量占单体总量的2.5%左右,引发剂用量为单体总量的0.5%时制备的苯丙乳液具有优良的稳定性和机械性能.     

不同偶联剂对苯丙乳液的改性效果

采用核壳乳液聚合法,利用前期研究已确定的核壳乳液合成配方,分别将不同种类和用量的硅烷偶联剂[γ-氨丙基三乙氧基硅烷(KH-550)、γ-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH-560)以及乙烯基三乙氧基硅烷(DL-151)]引入到苯丙乳液中,制得有机硅改性苯丙乳液。利用差示扫描量热分析(DSC)法、透射电镜(TEM)法和粒度分析法等多种检测手段,研究了偶联剂的种类与用量对乳液性能(包括粒径及其分布、钙离子稳定性、黏度、玻璃化转变温度及乳胶粒的核壳结构等)和乳胶膜性能(包括成膜性、吸水率、耐水性、附着力和铅笔硬度等)的影响。结果表明:乳胶粒的平均粒径最小为115 nm;DL-151和KH-560对苯丙乳液的改性效果较好,可以考虑将两者复配后共同改性苯丙乳液,以期获得综合性能较好的改性苯丙乳液。     

Highly stable polyimide composite films based on 1,2,4-triazole ring reinforced with multi-walled carbon nanotubes: Study on thermal,mechanical, and morphological properties

A novel diamine bearing aromatic pendant triazole ring, namely, 3,5-diamino-N-(1H-[1,2,4]triazol-3-yl)-benzamide, was successfully synthesized. The prepared diamine and a commercial dianhydride were reacted in situ in the presence of carboxylated multi-walled carbon nanotubes (MWCNTs) with stirring to give a homogeneous MWCNT/poly(amic acid) mixture which was then heated under a heating program to give a series of MWCNT/polyimide (PI) composites with different proportions of MWCNT (5, 10, and 15 wt%). The composite films were tested for different properties including spectral, morphological, thermal, and mechanical properties. Scanning and transmission electron microscopy revealed the modified MWCNTs were well dispersed in the PI matrix while the structure of the polymer and the MWCNTs structure were stable in the preparation process. The thermal stability of the films containing MWCNTs was improved as the MWCNT content increased from 5 to 15 wt% due to the improved interfacial interaction between the PI matrix and surface-modified MWCNTs. Tensile tests on the composites showed an increase in the elastic modulus and the yield strength, and decrease in the failure strain.     

CNT-reinforced adhesive joint between grit-blasted steel substrates fabricated by simple resin pre-coating method

A simple method of applying and distributing multi-walled carbon nanotubes (MWCNTs) onto grit-blasted steel substrates has been investigated in this study to overcome the difficulty of mixing MWCNTs in epoxy adhesives forming the MWCNT-reinforced adhesive joints. MWCNTs were dispersed in an acetone and resin (no hardener) solution with the weight ratio of 1:3:100 for MWCNT/resin/acetone, which was then applied onto the grit-blasted steel substrates. After evaporation of acetone, an ultra-thin layer of resin pre-coating kept well-distributed MWCNTs within the micro-cavities created by grit blasting. Epoxy adhesives (with hardener) were then applied to bond the steel substrates to create MWCNTs-reinforced adhesive joints. The results show that the MWCNT pre-coating (PC) method is beneficial to strong adhesive bonding. Most importantly, the MWCNT-PC method can be easily applied for structural applications on site. In the current study, MWCNTs were simply dispersed in the acetone and resin (no hardener) solution by simple rod stirring for around 1 minute, which can be adopted for large-scale applications. Scanning electron microscopy (SEM) observations on fracture surfaces and cross sections of the MWCNT-reinforced adhesive joints showed MWCNT micro-bundles were well dispersed within the epoxy adhesive joints taking the contour of microscopically uneven substrate surfaces.     

阳离子无皂苯丙聚合物分散松香胶的制备及应用

采用常压逆转工艺,以甲基丙烯酸-β-3-羟丙酯基三甲基氯化铵(DMHC)为自乳化阳离子单体、苯乙烯(St)为亲油单体、丙烯酰胺(AM)为亲水单体和羟甲基丙烯酰胺(NMAM)为交联剂,经氧化-还原引发共聚,然后加入松香,借助于反应形成的阳离子无皂苯丙乳液作分散乳化剂,制得阳离子苯丙共聚物分散松香胶。结果表明:当pH值为6～6.5、w[助留剂Al2(SO4)3]=0.5%、w[阳离子聚丙烯酰胺(CPAM)]=0.2%和w(阳离子分散松香胶施胶剂)=1.2%(相对于干浆料而言)时,将此阳离子分散松香胶应用于混合浆抄纸体系中,采用逆向施胶,纸张施胶度达84s,环压指数达7.36N·m/g,较空白样提高了17.7%。     

以丙烯腈改性淀粉为分散剂的阳离子苯丙乳液的研制

以丙烯腈改性淀粉为分散剂,采用自由基聚合法在淀粉分子链上接枝苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸二甲基氨基乙酯(DM)和丙烯酰胺(AM)等共聚单体,合成出一种新型的阳离子型淀粉接枝苯丙乳液施胶剂。探讨了K2S2O8/NaHSO3氧化还原型引发剂、共聚单体等对施胶剂施胶效果的影响。结果表明:当w(DM)=2%、w(AM)=0.3%、m(改性淀粉)∶m(单体)=1.0∶1.5、m(St)∶m(BA)=2.3∶1.0、引发剂中m(K2S2O8)∶m(NaHSO3)=1.0∶1.0且氧化剂w(K2S2O8)=0.10%时,施胶剂的施胶效果最佳,并且优于传统苯丙乳液施胶剂。     

Preparation of polyimide/multi-walled carbon nanotubes composite aerogels with anisotropic properties

In this study, a series of polyimide/multi-walled carbon nanotubes (PI/MWCNTs) composite aerogels with anisotropic properties were fabricated. First, the poly(amic acid) ammonium salt (PAS)/MWCNTs suspension was prepared by blending poly(amic acid), deionized water, triethylamine, MWCNTs, and CNT dispersant with the aid of ultrasonication treatment. Afterwards, the aqueous PAS/MWCNTs suspension was unidirectionally frozen at −65 ± 5°C, then followed by freeze-drying. Subsequently, the PI/MWCNTs composite aerogels were obtained after thermal imidization treatment. Morphology observations revealed that PI/MWCNTs composite aerogels exhibited a “hive-like” structure while viewed along the freezing direction, whereas a typical channel-like pore structure was observed perpendicular to the freezing direction. This typical structure rendered PI/MWCNTs composite aerogels with anisotropic properties such as heat conduction, electrical conductivity as well as electromagnetic interference shielding effectiveness when the aerogels were characterized at different directions.