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1.
以水珠为模板,采用溶剂散逸自组装法制备了表面具有特殊形貌的有序多孔膜. 以此多孔膜为模板制备了聚苯胺/聚氨酯(PANI/PU)的凹透镜阵列. 采用红外光谱(FTIR)和扫描电子显微镜(SEM)对界面聚合得到的PANI/PU纳米复合物的结构和凹透镜阵列的形貌进行了表征,研究了不同合成条件对纳米复合物导电性能的影响,并对PANI/PU凹透镜阵列的电学和光学性能进行了研究. 结果表明,PANI/PU凹透镜阵列同时具有导电性、电致收缩性和光衍射性质;其收缩率与外加电压成反比,而透光率与收缩率成正比.  相似文献   

2.
通过葡萄糖、丙烯酸羟乙酯和丁二胺反应,制备了含不饱和双键的糖基功能单体。 采用傅里叶红外光谱和核磁共振氢谱对合成的产物进行结构表征确定。 采用紫外光引发接枝聚合技术,将制备的不饱和糖单体接枝聚合到聚氨酯膜的表面,以衰减全反射模式下傅里叶红外光谱对表面接枝反应进行了确认。 通过静态水接触角实验和血小板黏附实验,分别对改性聚氨酯膜表面的亲水性和血液相容性进行了研究,结果表明,改性聚氨酯膜表面的接触角从86°降低到45°,血小板的粘附量由14.36×103 cells/mm2减少到2.57×103 cells/mm2,亲水性明显增强,血液相容性显著改善。  相似文献   

3.
用示差扫描量热法(DSC)研究了线形多嵌段聚氨酯(PU)与聚氯乙烯(PVC)、氯化聚氯乙烯(CPVC)共混相容性,说明了PU/VC、PU/CPVC的相容是由于共混物中形成了新的氢键的缘故.聚酯型聚氨酯与PVC、CPVC的相容性要好子聚酸型聚氨酯,CPVC与PU的相容性又要好于PVC.聚氨酯中硬段的引入不利于PU/PVC、PU/CPVC的相容性.  相似文献   

4.
采用十六胺作为表面修饰剂,通过一种简单易行的方法成功制备了纳米TiO_2微球.分别利用傅立叶红外光谱仪(FTIR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等表征手段对纳米TiO_2微球进行了结构和形貌表征.将制备的纳米TiO_2微球添加到水性聚氨酯基体(WPU)中,测试了其性能.结果表明,纳米TiO_2微球的添加显著提高了WPU的抗紫外线性能、耐水性和热稳定性等.  相似文献   

5.
聚氨酯一聚丙烯酸酯共聚乳液的合成研究   总被引:4,自引:0,他引:4  
以甲基丙烯酸β-羟乙酯封端的聚氨酯大分子单体与丙烯酸酯类单体进行乳液共聚,合成了以聚丙烯酸酯(PA)为主链、聚氨酯(PU)为侧链的接枝共聚物(PA-g-PU)乳液,用IR光谱和^1H NMR光谱对该聚氨酯大分子单体及PA-g-PU接枝共聚物进行了表征,并对影响聚氨酯-聚丙烯酸酯共聚合的因素进行了探讨。结果表明:聚氨酯大分子单体的加入对乳液聚合的速率造成较大的影响。该体系的表观活化自由能为99.39KJ/mol,Rp∝[I]^0.87,Rp∝[S]^0.12。  相似文献   

6.
用溶液法得到线形多嵌段聚氨酯(PU)与聚氯乙烯(PV)、氯化聚氯乙烯(CPVC)的共混物。用FTIR研究PU/PVC、PU/CPVC共混物的相容性,发现PVC、CPVC的加入破坏了PU中原来的氢键,并且PU中的炭基(C=0)与PVC、CPVC中的α-H形成了新的氢键,因而说明了PU/PVC、PU/CPVC共混物具有良好的相容性。  相似文献   

7.
以AgNO3为金属源,通过乙醇将与聚N-异丙基丙烯酰胺接枝聚丙烯腈/聚苯乙烯(PNIPAAm-g-PAN/PSt)聚合物微球表面酰胺基团配位的银离子(Ag+)还原,一步法制备了PNIPAAm-g-PAN/PSt载银复合微球。通过傅立叶变换红外(FTIR)和紫外-可见光光谱表征发现,由Ag+还原所得的Ag纳米颗粒被成功地固载在PNIPAAm-g-PAN/PSt 微球上;用透射电子显微镜(TEM)对载银微球的大小和形态进行了表征;热重分析(TGA)结果表明,固载在微球表面的银纳米颗粒的含量(质量分数)为12%;抗菌实验结果表明,所制备的载银微球具有抗革兰氏阴性菌的活性。  相似文献   

8.
柴淑玲  JIN  M  Martin 《中国化学》2008,26(4):775-780
以水性聚氨酯分散液为种子采用无皂乳液聚合新技术合成出了具有核壳结构的聚氨酯/聚丙烯酸酯(PU/PA)复合聚合物乳液。采用界面张力简化计算方法计算了聚合物与聚合物之间以及聚合物和水之间的界面张力,通过界面自由能变化最小的热力学判据对合成的复合乳液粒子的热力学平衡形态进行了预测。并利用透射电子显微镜观察和用接触角法测定的膜的表面极性对其进行了证实。结果表明:界面自由能变化的最小判据可以推广到PU/PA 体系,本文给出的界面张力的简化计算方法是可行的。  相似文献   

9.
热致相分离技术制备聚氨酯多孔膜的条件控制   总被引:5,自引:0,他引:5  
采用自制的模具 ,利用热致相分离 (TIPS)的原理制备了聚氨酯 (PU)多孔膜 ,并重点研究了聚合物浓度对多孔膜的表面形貌、孔度大小、孔隙率和透湿率的影响 .在不同的聚合物浓度条件下制备的PU多孔膜的共同特征是底面 (与成膜平台接触面 )光滑平整 ,孔洞尺寸较小 ,为纳米级 ;而表面 (与空气接触的自由面 )的形貌结构较为复杂 ,但都有明显的孔洞出现 ,且孔洞的尺度大于底面 ,在微米级以上 .聚氨酯 1,4 二氧六环 (DO)形成的是上临界共溶温度 (UCST)体系 ,在发生相分离后底面与表面粗化时间的不同是导致形貌结构差异的主要原因 .改变冷台温度或调整DO H2 O的比例也会对PU多孔膜的孔度大小和形貌结构产生明显的影响  相似文献   

10.
海藻酸钠/水性聚氨酯共混膜的结构表征和性能测试   总被引:5,自引:0,他引:5  
本文将海藻酸钠与聚酯型水性聚氨酯共混制膜,并通过红外光谱(FTIR)、X射线衍射(XRD)、扫描电镜(SEM)、紫外光谱(UV)、力学性能测试对共混膜的结构和性能进行了表征与测试。结果表明,共混膜中两种分子间存在着强烈的相互作用和良好的相容性,与纯海藻酸钠膜相比共混膜有较高的抗水性和断裂伸长率。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

14.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

15.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

16.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

17.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

18.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

19.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.  相似文献   

20.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

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