高分子化学课程教学改革与实践初探

高分子化学是高分子材料专业最重要的专业技术基础课之一,既包含了理论基础知识,又注重实验教学。《高分子化学》作为贵州大学高分子材料与工程专业的主干课之一,作者针对高分子化学课程教学内容多、概念多、推导多、关联多等问题,对高分子化学教学现状进行了分析,从教学体系、教学内容、教学方法、考核方式、教材编写等多个方面提出了课程教学改革的一些见解。实践表明,高分子化学课程教学改革与实践探索在激发学生兴趣,提高学生的综合能力上已经初见成效。     

Coryfolia D的全合成

以3,4-二羟基苯甲醛和2,4-二羟基苯乙酮为起始原料,经C-异戊烯基化、保护酚羟基、羟醛缩合、催化环化、DDQ脱氢及去保护基等反应,首次完成了天然产物异戊烯基黄酮Coryfolia D的全合成,总收率11.8％.所有新化合物的结构经1H NMR,IR和MS表征.     

电活化玻碳电极差分脉冲溶出伏安法测定磺胺嘧啶

采用线性循环溶出伏安法和差分脉冲溶出伏安法对磺胺嘧啶在电活化玻碳电极上的电化学行为进行了研究。玻碳电极在PBS溶液中(pH 7.0),用恒电位法在1.7 V阳极氧化400 s,在B-R缓冲溶液中,磺胺嘧啶在1.02V(vs.Ag/AgCl)处有一良好的氧化峰,在0.02～0.25 V/s范围内,其氧化峰电流与扫描速率呈良好线性关系,表明电极过程为受吸附控制的不可逆过程。差分脉冲溶出伏安法的氧化峰电流(Ipa)与磺胺嘧啶浓度1×10-6～1×10-4mol/L范围内呈良好的线性关系(r=0.9977),检出限为8.7×10-7mol/L(S/N=3)。方法已用于分析磺胺嘧啶片剂的分析。     

Influence of Steric Hindrance Between Hydrogen Atoms of Linkage Groups and Adjacent Phenyls on Properties of Polyimide

A diamine monomer 4,4′-methylenedianiline(MDA) was introduced to modify the polyimide of pyromellitic dianhydride(PMDA) and 4,4′-oxydianiline(ODA) by polycondensation. A series of polyamic acids was synthesized from MDA and ODA of different molar ratios with PMDA of sum mole of moles of MDA and ODA, and polyimide films were obtained by thermal imidization. Polyimide(PI) films were characterized by tensile testing, dynamic mechanical analysis(DMA), thermal gravimetry analysis(TGA), Fourier transform infrared spectroscopy (FTIR), wide X-ray diffraction(WAXD) and molecular simulation. With the increase of MDA content, the tensile strength and thermal decomposition temperature remained generally stable compared with those of PMDA/ODA polyimide. Unexpectedly, the glass transition temperature(T_g) and Young’s modulus increased from 388.7 ℃ and 2.37 GPa to 408.3 ℃ and 5.74 GPa, respectively. The results of WAXD and molecular simulation indicate the steric hindrance among hydrogen atoms of the linkage groups and adjacent phenyls enhanced the properties of the polyimide modified with MDA.     

用规整膜板对砷化镓的三维微结构图形加工刻蚀

以微齿轮图形结构作为规整模板 ,用约束刻蚀剂层技术对GaAs样品表面进行了加工刻蚀 .在有捕捉剂H3AsO3存在的情况下 ,规则微齿轮图形能够很好地在样品表面复制 .刻蚀结果与没有捕捉剂存在时的刻蚀结果做了比较 .另外还测试了不同方法制得膜板的性能 ,初步探讨了电化学模板的制作工艺 .     

X射线衍射仪新功能的开发及其应用

根据Ｘ射线衍射仪的结构特点,通过巧妙而简易的改装,增添了“同步照相”新功能。文中分析了开发新功能的可行性;列举了新功能在某些场合下,能使传统的照相法和现代的衍射仪法结合起来,取长补短的例子;指出新功能有助于提高分析测试水平,并可收到一机多用、节能高效的综合效果。     

Rapid Fabrication of Hollow SiO2 Spheres with Novel Morphology

The hydrolysis of tetraethoxysilane (TEOS) occurred on the surface of poly(methyl methacrylate) (PMMA) microshperes immediately after these microshperes were prepared in TEOS. Micron-sized hollow SiO2 spheres were obtained by calcination of the coated PMMA microshperes. It was found that the final hollow spheres were constituted by small SiO2 particles.     

Syntheses of 3-[5-Methyl-1-(4-Methylphenyl)-1,2,3-Triazol-4-yl]-6-Substituted-s-Triazolo[3,4-b]-1,3,4-Thiadiazoles

1,2,3-Triazole derivatives have been reported as inhibiting tumor proliferation, invasion, and metastasis^[1]. The fused l,3,4-triazolo[3,4-b]-1,3,4-thiadiazoles derivatives show various biological effects such as antifungal^[2], antibacterial, hypotensive and CNS depressant activities^[3]. We have reported several 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[3,4-b]-1,3,4-thiadiazoles in the previous paper^[4]. The novel 6-aryl-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazolo[2,4-b]-1,3,4-thiadiazoles 6a-j have been synthesized by the condensation of 4-amino-5-mercapto-3-[5-methyl-1-(4-methylphenyl)-1,2,3-triazol-4-yl]-s-triazole 5 with various aromatic carboxylic acids in the presence of phosphorus oxychloride. The mercaptotriazole 5 was prepared from 4,the latter being prepared from 1 throng 2 and 3. The title compounds 6 were depicted in scheme 1. The structures of these compounds were established by elemental analysis, NMR, MS and IR techniques.     

Two New Sesquiterpenes from Atractylodes macrocehpala

AtractylodesmacrocephalaKoidz(Compositae)isaperennialherbmainlydistributedintheZhejiangandAnhuiProvincesofChina.ItsrhizomehasbeenusedasatraditionalChinesemedicinefromancienttimesl'2.Twonewsesquiterpenes,BeishulenolideA1andPeroxiatractylenolideill2havebeenisolatedfromapetfoleumetherextractofthisherb.TheirstrUctureswereelucidatedonthebasisofspectralevidence,especiallyZDNMRmethodsandchemicalconversion.Compound1wasisolatedascolorlessneedlesfromethylacetate.HREIMSshoweditspeakatinjz=232.14…     

1,4-二酮吡咯并吡咯在聚合物太阳能电池的应用

1,4-二酮吡咯并吡咯(DPP)由于具有优异的共平面性和强烈的拉电子能力,从而被引入D-A型窄带隙共轭聚合物中调控聚合物材料的能隙和能级结构,拓宽在可见光区域的响应范围。近年来,DPP类聚合物太阳能电池材料的研究受到广泛关注,目前基于DPP的聚合物太阳能电池效率高已达9.64%。本文探讨了以DPP作为受体单元而噻吩衍生物、芴、咔唑和苯并二噻吩等作为给体单元制成的D-A型窄带隙共轭聚合物太阳能电池的研究进展,并探讨了聚合物材料结构与太阳能电池性能之间的内在构效关系。