联苯二酐型聚酰亚胺的透气性能与分子结构关系的研究

联苯二酐型聚酰亚胺的透气性能与分子结构关系的研究李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚酰亚胺，膜，气体分离，透气性，透气选择性联苯二酐（ＢＰＤＡ）型聚酰亚胺具有较高的透气选...     

聚四氟乙烯和石墨对聚醚酰亚胺摩擦学性能的影响

将聚四氟乙烯(PTFE)和石墨两类减摩耐磨填料填充到聚醚酰亚胺(PEI)中,表征其摩擦性能,利用扫描电子显微镜分析了磨损表面的显微结构,并分析了磨损机制.研究结果表明,PTFE和石墨的填充明显改善了PEI的摩擦磨损性,摩擦系数降低到0.3以下(纯PEI的摩擦系数为0.41),磨损率降低了3个数量级.在PTFE体系中,PTFE质量分数为10%时,PEI基共混材料的摩擦系数最低为0.23;而在质量分数为15%的石墨体系中,PEI基共混材料摩擦系数最低为0.27.磨损率随着填料含量的增加而逐渐下降,在填料质量分数为20%之后,摩损率下降平缓.因此PTFE和石墨的填充对PEI的摩擦学性能起到了很好的改善作用,而且PTFE比石墨的改善效果更优益.共混物的机械性能测试结果表明,在填料质量分数为5%~15%时,共混物具有良好的机械性能.     

Silica-containing polyetherimide hybrid films based on methyltriethoxysilane as precursor of inorganic network

Polyetherimide hybrid films containing 5–40% silica were prepared through a sol-gel process and thermal imidization by using methyltriethoxysilane as precursor of the inorganic network and a poly(amic acid) resulting from polycondensation reaction of 2,2-bis[4-(4-aminophenoxy)phenyl]propane with 2,2-bis[(3,4-dicarboxyphenoxy)phenyl]propane dianhydride. The properties of these films, morphology, water vapor sorption capacity, free surface energy, mechanical, thermal and electrical characteristics, were studied. The films exhibited good thermal stability, having an initial decomposition temperature above 470 °C and glass transition temperature in the range of 187–200 °C. They showed low dielectric constant and low dielectric loss in a large frequency field. Gas permeation tests using small molecules (He, N₂, O₂ and CO₂) at 6 bar and 30 °C indicated that the hybrid films containing higher silica content showed higher permeability for all the tested gases.     

裂解气相色谱-质谱法研究聚醚酰亚胺的热裂解行为

采用裂解气相色谱-质谱技术研究了聚醚酰亚胺(PEI)在550℃、650℃和750℃裂解温度下的热分解行为.随着裂解温度上升,裂解产物明显增加.在750℃时聚合物分子链断裂完全,共鉴别到25种碎片组分.PEI热分解的碎片中叔丁基苯酚、叔丁基甲基苯酚、苯酚、苯胺、氰苯、2-苯基-1H-异吲哚-1,3(2H)-二酮等5种裂解产物最重要,因此可以依据这几种化合物定性鉴别聚醚酰亚胺.依据热分解产物的数量以及结构推断降解机理为:裂解首先从醚键开始,其次是酰胺基团中的C-N键,然后再经过一系列消除反应、成环反应、重排反应等形成多种裂解碎片.     

静电纺丝法制备聚醚酰亚胺纤维膜的结构和介电性能研究

采用静电纺丝法制备了聚醚酰亚胺(PEI)纤维膜,通过扫描电子显微镜(SEM)和偏振红外对PEI纤维膜的微观结构进行研究.实验结果显示纺丝液溶剂决定了PEI的可纺性,以N-甲基吡咯烷酮(NMP)为溶剂时,空气湿度显著地影响纺丝过程以及纤维的形态.在相同纺丝工艺条件下,随着纺丝液浓度的增加,所得PEI取向纤维沿辊筒收集方向的排列规整性提高,纤维平均直径由405 nm增加到3.25 μm.PEI纤维膜介电性能的研究表明,取向纤维膜的介电常数很小,最低可达到1.1,其介电损耗也维持在较低的水平,纤维膜的接收方式以及热牵伸处理会对PEI纤维膜的介电性能产生影响.     

一种新型含萘聚醚酰亚胺的合成与表征

本文合成了一种新型含萘酰亚胺六元环结构的双氯单体BCNPI, 然后将其与双酚A双钠盐在环丁砜中高温缩聚, 得到一种新型含萘聚醚酰亚胺, 并对其基本性能进行表征.     

聚醚酰亚胺耐热大分子偶联剂增强增韧石英纤维/含硅芳炔复合材料

设计并制备了一种新型乙炔基封端聚醚酰亚胺大分子偶联剂(BDA-K),探究了其对石英纤维(QF)/含硅芳炔(PSA)复合材料界面增强增韧的效果.在常温下,加入大分子偶联剂的复合材料层间剪切强度、弯曲强度和缺口冲击强度分别提高了54.1%,59.0%和23.8%;在250℃时,层间剪切强度和弯曲强度保留率分别达到89.0%和89.6%,500℃时保留率分别达到63.3%和67.9%.傅里叶变换红外光谱和X光电子能谱分析结果表明,BDA-K参与PSA的交联固化,与QF发生有效化学键合;热重分析(TGA)结果表明,由于BDA-K的分子结构中引入耐热官能团酰亚胺环等,使其大分子偶联剂的T_(d5)达到489℃;扫描电子显微镜(SEM)结果表明,柔软的大分子层提供了适中的界面结合,使强度和韧性都得到提高.     

Reduced viscosity, rheology and morphological properties of sulfonated poly (ether ether ketone): Polyetherimide blends

Blends of poly (ether ether ketone) (SPEEK) and polyetherimide (PEI) were prepared in five different weight ratios, using N,N-dimethylacetamide (DMAc) as solvent. Reduced viscosity and rheological parameters of these blends were investigated. Cannon–Fenske viscometer was used to study the viscoelastic parameters of the salt-free polyelectrolyte blends and the data obtained was fitted in Fuoss–Strauss equation. Effects of temperature and concentration have been investigated. It was observed that the storage modulus (G′) and dynamic viscosity (η′) of the blends varies significantly as compare to pure SPEEK and PEI. Surface morphology and thermal behavior of the membranes were studied using scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). Form SEM results it was observed that the phase separation occurs at 25% PEI contents in blends.     

A novel polyethyleneimine-decorated FeOOH nanoparticle for efficient siRNA delivery

Despite the promising prospect of small interfering RNA(siRNA) for the treatment of diverse diseases,it remains challenging to develop novel delive ry materials to desired tissues and cells.In this study,a novel iron oxyhydroxide(FeOOH) nanoparticle(NP) whose surface was modified with branched polyetherimide(PEI) was developed to deliver siRNA into the cancer cells.It was demonstrated that PEI-FeOOH(PFeOOH) efficiently complexed siRNA,mediated effective cellular uptake and endosomal escape,thereby triggering robust gene silencing in vitro.In addition,PFeOOH/siRNA formulation loading with anti-RRM2 siRNA effectively inhibited the growth of tumor tissues,and exhibited excellent safety profiles in vivo.Therefore,this study conceptually provided a FeOOH-based nucleic acid delivery vesicle which can potentially use to achieve diagnosis and therapy simultaneously.     

单醚二酐型聚醚酰亚胺的透气性能与分子结构之间关系的研究

合成了一系列单醚二酐型聚醚酞亚胺（ＰＥＩ），研究了它们对Ｈ２、ＣＯ２、Ｏ２、Ｎ２和ＣＨ４５种气体的透过性能与分子结构的关系．结果表明，这类聚醚欧亚胺的分子结构对其透气性和透气选择性有很大的影响，聚合物的自由体积和链段活动性是控制透气性和透气选择性的主要因素．二苯醚四酸二酐（ＯＤＰＡ－４．４＇－二Ｊ氨基二苯异丙烷（ＩＰＤＡ）具有很大的自由体积和较小的链段活动性、很大的透气性和较小的透气选择性，ＯＤＰＡ—４，４’－二氨基二苯酮（ＤＡＢＰ）具有很小的自由体积和较小的链段活动性、很小的透气性和较大的透气选择性，ＯＤＰＡ—３，３’－二甲基二苯甲烷二胶（ＤＭＭＤＡ）具有较大的自由体积和较小的链段活动性、很大的透气性和很大的透气选择性．