苯并噁唑侧基聚酰亚胺的制备与性能

为了改善聚酰亚胺的不溶不熔性,一类可溶性苯并噁唑侧基聚酰亚胺树脂被成功制备。从合成的前体侧链为邻羟基苯胺酰胺结构的聚酰亚胺体系出发,进一步催化环化邻羟基苯胺酰胺为苯并噁唑结构,制备了苯并噁唑侧基聚酰亚胺。对这两类不同侧链结构的聚合物树脂进行了红外光谱的结构表征,以及最终成膜的溶解性能、力学性能和耐热性能测试。研究结果表明,苯并噁唑侧基聚酰亚胺溶解于非质子极性有机溶剂中,其力学性能优于相应的主链型聚酰亚胺,且TGA分析表明,其初始分解温度高达597℃,有望用于航空航天方面高强、高模、耐高温的结构材料。     

苯并二噁唑系列聚合物的合成及其光电性能的研究

以4,6-二氨基-1,3-苯二酚盐酸盐为原料,分别与对苯二甲酸、1,4-萘二甲酸、2,6-萘二甲酸、2,5-噻吩二甲酸、4,4’-(1,2-二苯基乙烯)二甲酸、反丁烯二甲酸在多聚磷酸介质中反应,合成了单环的聚(1,4-亚苯基)苯并二噁唑(PBO)、稠环的聚(1,4-亚萘基)苯并二噁唑(1,4-PNBO)和聚(2,6-亚萘基)苯并二噁唑(2,6-PNBO)、杂环的聚(2,5-亚噻吩基)苯并二噁唑(PTBO)、含有两个苯环的聚-4,4’-亚(1,2-二苯乙烯基)苯并二噁唑(4,4’-PDPEBO)和直链烯烃的聚亚乙烯基苯并二噁唑(PBOV)。采用傅立叶红外光谱、元素分析对系列聚合物的结构进行了表征。利用电导率仪和荧光光谱仪,对系列聚合物的结构与性能之间的关系进行了分析。研究结果表明,PBO、1,4-PNBO、2,6-PNBO、4,4’-PDPEBO、PTBO和PBOV电导率依次减小;系列聚合物的荧光发射光谱和激发光谱的形状都相近,聚合物的最大发射峰波长是一致的,其中2,6-PNBO的荧光强度最强。     

含苯并噁唑半芳香聚酰胺的合成与表征

为了得到同时具有优良耐热性能和易加工性能的新型半芳香聚酰胺,以5-氨基-2-(对氨基苯)苯并噁唑(ABO)和己二酸基于Yamazaki磷酸化过程合成了聚己二酰对苯撑苯并噁唑二胺(BO6).研究了反应温度对聚合物分子量的影响,并通过FTIR、1H-NMR对其结构进行了表征;利用DSC、TG对其热性能进行了研究.结果表明:反应温度在90℃左右时高聚物获得了最高的粘数.该聚合物的耐热性较脂肪族聚酰胺有较大幅度的提高,同时该聚合物具有较好的耐溶剂性能.     

主链插入苯并二噁唑环的PPV聚合物的合成及其光电性质

以对氰基氯苄和4，6-二氨基间苯二酚为主要原料，首先合成2，6-二（4-氯甲基苯基）苯并[1-2，4-5＇]二噁唑，又通过2，6-二（4-氯甲基苯基）苯并[1-2，4-5＇]二噁唑与对苯二甲醛的Wittig反应，设计合成了一种新的主链插入苯并[1-2，4-5＇]二噁唑环的PPV聚合物（BO-PPV），通过红外光谱、核磁共振谱、凝胶渗透色谱等分析方法对其结构进行了表征。并研究了该聚合物的光电热物理特性，结果表明：该聚合物的Tg为235℃，Td为410℃，电致发光谱峰值λmax为494nm，由ITO／BO-PPV／Al组成的单层器件在电压15伏特，发光亮度可达650cd／cm^2，发光效率0．24cd／A。     

聚对苯撑苯并二噁唑的合成方法进展

聚对苯撑苯并二噁唑是一类具有独特刚性结构的芳香族液晶高分子,因其具有高强度、高模量及耐高温性能而成为杂环聚合物中最有发展潜力的一类聚合物,并受到广泛关注。总结、分析了近年来制备聚对苯撑苯并二噁唑的方法,如对苯二甲酸法、对苯二甲酰氯法、DAR/TPA盐法等,并展望了聚对苯撑苯并二噁唑聚合物的发展方向和趋势。     

三阶非线性光学材料甲基噁二唑聚炔合成研究

设计合成了一种含甲基噁二唑功能基的聚炔材料聚(2-对甲基苯基-5-对乙炔基苯基-1,3,4-噁二唑)。对制得的聚合物和单体进行FT-IR、~(1)H-NMR、紫外、荧光和热重(TGA)表征及Z扫描(Z-scan)技术评价,结果表明:聚(2-对甲基苯基-5-对乙炔基苯基-1,3,4-噁二唑)在失重5%时,热分解温度为389℃,较之单体(312℃)有较大提高,热性能较好;非线性吸收系数为-1.53×10~(-10)cm/W,非线性折射率为4×10~(-17)cm~2/W,三阶非线性极化率为3.00×10~(-11)esu,三阶非线性光学性能良好,与侧链烷氧基取代的噁二唑聚炔相比性能显著提高。     

聚(芳基醚1,3,4-噁二唑)类聚合物的合成及表征

为改善芳香族聚噁二唑的加工性,合成了一种含噁二唑的双氟单体,将其与二酚单体进行溶液缩聚,得到一系列含有醚键与C(CH3)2,CCH3C6H5等官能团的新型聚(芳基醚1,3,4-噁二唑)(PEOD),其黏度达1.0 dL/g,噁二唑成环率达100%,并通过核磁氢谱(1H-NMR)和元素分析(EA)证实了其化学结构。通过热重分析(TGA)对PEOD的热稳定性进行了表征,结果表明,这些聚合物具有优良的热性能。通过溶解性试验表明PEOD能够溶解于三氯甲烷(CHCl3)、二氯甲烷(CH2Cl2)、四氢呋喃(THF)等有机溶剂,其溶解性比聚对苯撑噁二唑(p-POD)及对间苯噁二唑(p/m-POD)有了较大的改善。     

噻吩类电致发光材料的能级结构及光电性能研究

用循环伏安法测试了一系列噻吩类聚合物和单体的氧化还原电位,确定了系列化合物的能级结构,比较了主链上不同取代基团及形成共聚物对聚合物能级和光电性能的影响,为高性能发光器件的制作提供了依据.结果表明,随着噻吩环3位取代烷基碳链的增长,单体带隙减小;形成聚合物有利于降低带隙;通过共聚方式引入聚合物主链的噁二唑吸电子基团可以改进其电子传输性能.     

聚噁二唑芳亚胺联噻吩的合成及性能

以3,3’-二溴-2,2’-联噻吩和2,5-二(4-氨基苯基)-1,3,4-噁二唑为单体,通过钯催化CAr-N偶联合成了新型功能高分子聚噁二唑芳亚胺联噻吩(POXDIBT)。通过分子模拟、傅里叶变换红外光谱、核磁共振氢谱、热重、紫外可见吸收光谱、荧光光谱等分析技术对聚合物的分子结构、分子链构象、热稳定性及光学性能进行了研究。结果表明,该聚合物呈现锯齿形分子链构象,具有较好的溶解性能,热分解温度Td=323℃,在339nm处具有强吸收,激发波长为340nm时,荧光发射波长为401nm。     

2,5-二[4-(4-溴苯氧基亚甲基)苯基]-1,3,4-噁二唑的合成与表征

以对甲基苯甲酸、水合肼为原料,通过关环、溴化、醚化合成了一种新型含噁二唑功能基有机聚合物电致发光材料单体2,5-二[4-(4-溴苯氧基亚甲基)苯基]-1,3,4-噁二唑,其化学结构由红外光谱仪及核磁共振氢谱仪进行了表征,产品总收率22.64%.     

Differences of internal structures between amphiphilic and hydrophobic block-copolymer nanoparticles

In this report, we show a novel and simple preparation method for obtaining block-copolymer nanoparticles. Regular-sized polymer nanoparticles are formed after evaporation of a good solvent from a polymer solution containing a non-volatile poor solvent and the volatile good solvent. Nanoparticles of poly(styrene-b-sodium acrylate), poly(styrene-b-4-vinylpyridine), and poly(styreneb-isoprene) were prepared by using this method. We also discuss the difference of internal structures between amphiphilic and hydrophobic block-copolymer nanoparticles. From the results of scanning transmission electron microscope (STEM) imaging, the particles of amphiphilic block-copolymers have hollow structures were observed. On the other hand, the particles of a hydrophobic block-copolymer form lamellar micro-phase separation structures.     

含硼杂化高分子材料

本文对含硼高分子材料的研究进行了回顾与展望 ,指出含硼高分子材料在航空航天及国防等领域有广阔的应用前景     

Effect of urea and pantothenol on the permeation of progesterone through excised rat skin from polymer matrix systems

Standard in vitro permeation experiments, using excised rat skin, were carried out to establish the release profile and permeation behavior of progesterone from polymethacrylate (PMA), polyvinylpyrrolidon (PVP), and polyvinylalcohol (PVA) transdermal systems. Data obtained show significant differences in release characteristics from each polymer systems. The greatest amount of progesterone was released from the PVA system. The influence of urea and pantothenol on progesterone release was also investigated. Release data were compared with the permeation rates of progesterone across excised rat skin. The highest permeation rates were measured from PVA matrices containing 5% urea (860 ± 138 μg/cm²; cumulative amount permeated in 24 hr) and from PVP matrices containing 6% pantothenol (660 ± 73 μg/cm²; cumulative amount permeated in 24 hr). A good correlation between release and permeation data was found with the polymer matrices; however, this was not the case when additives were included.     

Effect of Drug,Formulation, and Process Variables on Granulation and Compaction Characteristics of Heterogeneous Matrices: Part II. HPMC and PVP Systems

Abstract

A heterogeneous matrix comprising hydroxypropyl methylcellulose (HPMC) and polyvinylpyrrolidone (PVP) at various ratios was granulated using acetaminophen and pseudoephedrine as model drugs. The effect of drug, polymer ratio, total polymer loading, and volume of the granulating fluid on granule growth, granule size distribution, compaction, and tablet properties of the matrix was studied. Formulations containing both acetaminophen and pseudoephedrine required less water to granulate than those containing only acetaminophen. Moreover, the particle sizes of granules prepared with acetaminophen and pseudoephedrine were smaller than those containing only acetaminophen. Tablet hardness increased and friability decreased considerably in all formulations containing pseudoephedrine. In general, the tablet hardness and tablet disintegration time varied with changes in total polymer loading, fraction of HPMC in the matrix, and composition of the model drug(s). All the matrix systems studied showed good flow characteristics at different polymer loadings or HPMC-PVP ratio for matrices formulated with either acetaminophen or both acetaminophen and pseudoephedrine. The results of this study indicate that the presence of drug and/or other excipient(s) in the formulation affects the hydration characteristics of the matrix polymer(s) and compression properties of the granules.     

Effect of Drug, Formulation, and Process Variables on Granulation and Compaction Characteristics of Heterogeneous Matrices: Part II. HPMC and PVP Systems

A heterogeneous matrix comprising hydroxypropyl methylcellulose (HPMC) and polyvinylpyrrolidone (PVP) at various ratios was granulated using acetaminophen and pseudoephedrine as model drugs. The effect of drug, polymer ratio, total polymer loading, and volume of the granulating fluid on granule growth, granule size distribution, compaction, and tablet properties of the matrix was studied. Formulations containing both acetaminophen and pseudoephedrine required less water to granulate than those containing only acetaminophen. Moreover, the particle sizes of granules prepared with acetaminophen and pseudoephedrine were smaller than those containing only acetaminophen. Tablet hardness increased and friability decreased considerably in all formulations containing pseudoephedrine. In general, the tablet hardness and tablet disintegration time varied with changes in total polymer loading, fraction of HPMC in the matrix, and composition of the model drug(s). All the matrix systems studied showed good flow characteristics at different polymer loadings or HPMC-PVP ratio for matrices formulated with either acetaminophen or both acetaminophen and pseudoephedrine. The results of this study indicate that the presence of drug and/or other excipient(s) in the formulation affects the hydration characteristics of the matrix polymer(s) and compression properties of the granules.     

Synthesis and characterization of a novel series of unsymmetric dimesogenic compounds containing cholesteryl ester and nitroazobenzene moieties

The synthesis and mesomorphic properties of a novel series of dimesogenic compounds containing cholesteryl ester and 4′-nitroazobenzene moieties were reported. The two mesogenic units of these compounds were linked through dicarboxylic ester bonds, and the alkylene spacers' lengths were 2, 4, 6 and 8 methylenes. Their chemical structure and liquid crystalline properties were characterized by FT-IR, ¹H NMR, hot-stage coupled polarizing optical microscopy and DSC. The results showed that these dimesogenic compounds were cholesteric liquid crystals over a wide range both in heating and cooling processes. They exhibit iridescent colors in the liquid crystalline states. These compounds are potential candidates for applications in liquid crystalline exhibition and optical-electric functional devices.     

Evaluation of polyvinyl alcohols as mucoadhesive polymers for mucoadhesive buccal tablets prepared by direct compression

The purpose of the present work was to evaluate polyvinyl alcohols (PVAs) as a mucoadhesive polymer for mucoadhesive buccal tablets prepared by direct compression. Various polymerization degree and particle diameter PVAs were investigated for their usability. The tensile strength, in vitro adhesive force, and water absorption properties of the tablets were determined to compare the various PVAs. The highest values of the tensile strength and the in vitro adhesive force were observed for PVAs with a medium viscosity and small particle size. The optimal PVA was identified by a factorial design analysis. Mucoadhesive tablets containing the optimal PVA were compared with carboxyvinyl polymer and hydroxypropyl cellulose formulations. The optimal PVA gives a high adhesive force, has a low viscosity, and resulted in relatively rapid drug release. Formulations containing carboxyvinyl polymer had high tensile strengths but short disintegration times. Higher hydroxypropyl cellulose concentration formulations had good adhesion forces and very long disintegration times. We identified the optimal characteristics of PVA, and the usefulness of mucoadhesive buccal tablets containing this PVA was suggested from their formulation properties.     

噁二唑类电子传输材料的研究进展

1,3,4-噁二唑环是一个具有高电子亲和势和空穴阻挡作用的基团,含该基团的化合物是一类具有发光性能的电子传输材料.本文综述了对含1,3,4-噁二唑环的有机小分子、星状、枝化分子和聚合物的电子传输材料的进展,并且对该类化合物作了简要的展望.     

本征型自修复高聚物粘结炸药的制备与损伤愈合性能

为减轻高聚物粘结炸药(PBX)由于力、热等环境因素所产生的微裂纹等损伤对于其性能与使用寿命的影响,根据颗粒填充高分子复合材料的结构特性,设计合成了含DA键的本征型自修复高聚物粘结剂,以期实现PBX内部损伤的自主修复。研究结果表明,采用含可逆DA共价键的TAPE-DAPU为粘结剂,设计制备的PBX材料具有较强的损伤愈合能力,当损伤较轻时,该PBX的强度恢复率超过95%,对于较严重的贯穿性损伤,其修复效率也在65%以上。      

In situ synthesis of transparent fluorescent ZnS–polymer nanocomposite hybrids through catalytic chain transfer polymerization technique

We report the controllable synthesis of zinc sulfide (ZnS) nanocrystals (NCs)/polymer transparent nanocomposite hybrids in situ based on the catalytic chain transfer polymerization (CCTP) technique. Firstly, a polymeric ligand PMAA [PMAA = poly(acrylic acid)] with controllable low-molecular-weight and a terminal double bond was synthesized through CCTP. Secondly, with the use of this versatile polymeric ligand containing a large number of anchors as the stabilizer, the ZnS NCs were fabricated. Finally, the surface polymeric ligands containing terminal double bonds were copolymerized with methyl methacrylate monomer to form NCs–polymer hybrids through free radical polymerization. The properties of as-prepared ZnS NCs and their nanocomposite hybrids were thoroughly investigated by Fourier transform Raman spectra, Fourier transform infrared spectrum, transmission electron microscope, ultraviolet–visible, photoluminescence, and thermogravimetric analyses measurements. The spectroscopic studies reveal that ZnS–polymer nanocomposite hybrids have good optical properties.