芳香酸改性酰胺酰亚胺聚氨酯的合成与性能

以偏苯三酸酐、甲苯二异氰酸酯及间／对苯二甲酸(m／p—PTA)合成的酰胺酰亚胺二元酸(AIDA—I或AIDA—Ⅱ)，与己二酸、新戊二醇及甘油熔融共缩聚得到酰胺酰亚胺聚酯多元醇，采用该多元醇与封闭型多异氰酸酯经高温脱封交联后成功地制得一种交联型酰胺酰亚胺聚氨酯膜。结果表明，所合成的酰胺酰亚胺聚氨酯膜的热分解稳定性、耐溶剂性、拉伸强度和模量，与无酰胺酰亚胺基团改性的聚氨酯膜相比有显著提高，其中以AIDA-Ⅱ改性的酰胺酰亚胺聚氨酯膜的综合性能更优。     

铝塑复合用聚氨酯胶粘剂的制备及性能研究

以聚酯、聚醚混合多元醇和异佛尔酮二异氰酸酯为主要原料,制备了一种低粘度无溶剂型聚氨酯覆膜胶粘剂。研究了聚酯、聚醚混合多元醇的配比对胶粘剂合成时间、粘度、抗水性能和粘结强度的影响;同时,探讨了催化剂的添加对胶粘剂综合性能的影响。结果表明:由混合聚酯、聚醚多元醇合成的聚氨酯胶粘剂粘度低、易涂覆且耐水性得以改善,但比例必须适宜,以2种多元醇所含羟基物质的量比为0.3:0.7为佳;催化剂的加入虽能显著提高固化速度,但降低了胶粘剂的剥离强度,不利于胶粘剂综合性能的改善,故应酌情适量添加。     

高结晶性聚酯型水性聚氨酯的制备及表征

由己二酸、己二醇和苯二甲酸磺酸钠缩聚，制得分子量为1425的聚酯多元醇。将自制的聚酯多元醇与六次甲基二异氰酸酯及二羟甲基丙酸等单体在无有机溶荆参与的情况下进行预缩聚，然后将预聚体直接分散于水中，再经乙二胺扩链，制得高分子量、高结晶性聚酯型的水性聚氨酯。用红外光谱、核磁共振氢谱、差示扫描量热以及宽角X射线衍射等手段对聚酯多元醇和聚氨酯的结构进行了表征。     

含苯磺酸基水基聚氨酯的制备及表征

由苯二甲酸磺酸钠、己二酸和己二醇缩聚,制得分子量为1825的聚酯多元醇。将自制的聚酯多元醇与六次甲基二异氰酸酯、异佛二嗣二异氰酸酯以及二羟甲基丙酸等单体在无有机溶剂参与的情况下进行预缩聚,最后将预聚体直接分散于水中,经乙二胺扩链即制得高分子量、高结晶性的水性聚氨酯．用红外光谱、核磁共振氢谱、示差扫描量热以及宽角X射线衍射等手段对聚酯多元醇和聚氨酯进行了表征．     

基于二聚酸的聚酯多元醇的合成及其热塑性聚氨酯弹性体的制备及性能研究

以二聚酸、己二酸和新戊二醇为原料,在高温、氮气保护下,合成了一种相对分子质量为2000的聚酯多元醇.以合成的聚酯多元醇、二苯基甲烷二异氰酸酯、1,4-丁二醇为原料,采用预聚物法合成了热塑性聚氨酯弹性体,研究了其力学性能、耐水性、抗水解性、耐化学药品性,并与聚己酸内酯、聚四亚甲基醚二醇、聚己二酸乙二醇、聚己二酸丁二醇的热塑性聚氨酯产品进行了比较.     

制备方法对聚氨酯材料性能的影响

采用聚酯多元醇(PEA)和聚醚多元醇(PTMG)为混合软链段,考察了相同原料组成而不同制备方法对聚氨酯材料力学性能及动态行为的影响。方法一:将PEA和PTMG混合后制成预聚体,用扩链剂(MOCA)扩链后合成聚氨酯;方法二:将PEA和PTMG分别制成备预聚体,按照一定比例取出2种预聚体,再按各自的扩链系数加入MOCA,反应数分钟后将两者混合制备PEA/PTMG混合软链段聚氨酯。动态力学分析表明,不同制备方法对材料的耗能模量及玻璃化转变温度有较大影响,也证实了按照方法二制备的聚氨酯具有多微区结构。论文的研究模式对制备多种不同微区共存的聚氨酯是有益的。     

聚酯型聚氨酯油墨连接料的合成及性能研究

指出了聚酯型聚氨酯油墨使用简便、性能稳定、附着力强、光泽度优、耐热性好,能适合各种印刷方式。在制备聚酯多元醇的基础上,通过扩链反应,制备了酯溶性聚氨酯及聚氨酯油墨,并利用红外等对样品的性能进行了表征。     

硅烷改性水性聚氨酯表面施胶剂的制备与性能研究

以甲苯二异氰酸酯、混合多元醇为基本原料,N-甲基二乙醇胺为亲水扩链剂,有机硅为改性剂,通过醋酸中和反应制备出一种可用于纸张表面施胶的自乳化阳离子水性聚氨酯乳液;研究了硅烷用量、预聚温度、R值(体系中异氰酸酯基和羧基的摩尔比)、聚酯＼聚醚质量比对乳液性能和施胶效果的影响.结果表明:硅烷用量为4.5％,预聚温度为60℃,R值为1.10,聚酯＼聚醚质量比为3.6时制备的乳液性能良好;FT-IR分析表明有机硅烷已通过化学方法结合到聚氨酯分子链中;TGA分析表明有机硅的加入对水性聚氨酯耐热性有明显提高;粒径分析表明,有机硅的加入能使乳液粒子分布更均匀且粒径更小;施胶效果表明水性聚氨酯对改善纸张强度作用明显,有机硅烷的加入能显著提高纸张的施胶度.     

封端型水性聚氨酯树脂的结构与性能

以聚酯多元醇、甲苯二异氰酸酯和二羟甲基丙酸为主要原料,丙烯酸单体封端,加入改性剂三羟甲基丙烷脱水蓖麻油酸酯(TMPDCO),制备出稳定的水性聚氨酯分散体。涂膜耐化学品性和凝胶含量测定说明,TMPDCO的加入增加了涂膜的交联度,提高了涂膜的耐化学品性。差示扫描量热法测试表明,加入封端剂增加了涂膜交联度,涂膜玻璃化转变温度明显提高。力学性能测试说明,聚酯作为软段的水性聚氨酯树脂较聚醚型耐水性好。X射线衍射分析说明,随着硬段规整度的增加,衍射峰中心依次向高角度偏移。红外表征说明,不同硬段合成水性聚氨酯的氨基甲酸酯键波数不同。     

水性聚氨酯防水涂膜材料的制备与性能

为了研究多元醇类型对水性聚氨酯防水涂膜材料性能的影响,选用分子量均为1 000的聚酯型、聚醚型多元醇为软段,通过预聚体法制备了一系列水性聚氨酯(WPU)分散体;探讨了WPU的粒径、黏度、结构及结晶性、水抵抗性能。结果表明:制备的WPU分散体粒径较小;聚酯多元醇型[聚己二酸乙二醇酯(PB)、聚碳酸酯(PCL)]WPU膜的拉伸强度、结晶性能高于聚醚多元醇型[聚丙二醇(PPG)、聚四氢呋喃醚二醇(PTMG)]的,但是断裂伸长率低于聚醚多元醇型的WPU膜;其中PTMG型WPU膜的水接触角最大,达到66.5°,吸水率最小(6.2%),防水性最佳,综合性能最好,最适合用作环境友好型纤维织物防水涂膜材料。     

乙醇胺改性酰亚胺聚酯聚氨酯的热性能及热解过程

研究了前文所制备酰亚胺聚氨酯的热性能及热解过程。研究采用了不同温度及不同热老化条件下的拉伸试验、热分析(TGA)与质谱(MS)的联用技术(TGA-co-MS)和红外光谱(FT-IR)的多技术研究方法。研究表明,酰亚胺聚氨酯在100℃或230℃热老化2 h后仍显示较好的力学性能。酰亚胺聚氨酯热解过程检测到荷质比分别为44、54、56、84、88、95、106的7种离子分子。其中荷质比为44的离子分子是主要的热解产物,来自于分子链中的酯键和氨基甲酸酯键的热解。酰亚胺结构的引入对分子链中氨基甲酸酯键及酯键起到较好的屏蔽作用,显著提高了聚氨酯的耐温性和热老化性能。     

Uniform Ag Nanocubes Prepared by AgCl Particle–Mediated Heterogeneous Nucleation and Disassembly and Their Mechanism Study by DFT Calculation

Uniform Ag nanocubes are reproducibly synthesized by a AgCl particle‐mediated heterogeneous nucleation and disassembly process in polyol chemistry. By introducing N,N‐dimethylformamide (DMF) in a conventional polyol method with HCl etchant, Ag nanocrystals (NCs) begin to be nucleated on the surface of AgCl‐precipitated particles due to the promoted reduction reaction by DMF. The nucleated Ag NCs on the AgCl particles are grown to Ag nanocubes in shape by consuming Ag sources from the AgCl mother particles. Eventually the grown Ag nanocubes are disassembled from the mother AgCl particles because the AgCl particles are fully digested by the growing Ag nanocubes. Density functional theory calculation confirms that the Ag atoms can be favorably deposited on the (100) facet of AgCl particles and the Ag nuclei on the AgCl particles tend to reveal (100) facet.     

The mechanical properties of insert-molded poly (ether imide) (PEI)/C fiber poly (ether ether ketone)(PEEK) composites

The mechanical properties of insert-molded poly(ether imide) (PEI)/carbon fiber poly(etheretherketone) (CF PEEK) have been examined. Bimaterial composite specimens were constructed by injecting CF PEEK into a mold containing one-half of a PEI tensile specimen. These PEI/CF PEEK composites retained much of their strength and dimensional integrity at temperatures as high as 200°C. Variations in test speed had little affect on breaking strains or stiffness. For two grades of PEI examined, properties were independent of the molecular weight of the PEI. Ultimate properties and fracture surfaces suggested good adhesion between the PEI and CF PEEK, possibly aided by miscibility between the two materials. The PEI/CF PEEK bimaterial composites behaved similarly to PC/CF PEEK specimens, but exhibited higher breaking stresses and moduli, both at room and elevated temperatures.     

两亲嵌段共聚物的合成及纳米自组装

首先用苄氧羰基赖氨酸和三光气反应合成苄氧羰基赖氨酸酸酐,然后将聚乙二醇中活性较弱的羟基转化为氨基,最后以双端氨基聚乙二醇作为引发剂,采用阴离子开环聚合合成了聚(Nε-苄氧羰基赖氨酸)-聚乙二醇-聚(Nε-苄氧羰基赖氨酸)(PLL(Z)-PEG-PLL(Z))。PLL(Z)-PEG-PLL(Z)经去保护后得到带正电荷的聚赖氨酸-聚乙二醇-聚赖氨酸(PLL-PEG-PLL)。PLL(Z)-PEG-PLL(Z)在水溶液中自组装形成的聚集体类似于纳米多孔聚集体结构,具有疏松的空洞,原子力显微镜观测其呈球形,其大小为220 nm左右。     

嵌段共聚有机硅氧烷的合成及其氧化热稳定性研究

采用对－双（二甲基－锂氧硅基）苯撑作引发剂，Ｎ，Ｎ－二甲基甲酰胺作促进剂，不同的有机环四硅氧烷作单体，制备了数种不同组成的聚二苯基硅氧烷（Ｐ）－聚二甲基－甲基乙烯基硅氧烷（ＭＶ）－聚二苯基硅氧烷（Ｐ）三嵌段（Ｐ－ＭＶ－Ｐ）共聚物。这些嵌段共聚物，经石油醚溶解，乙醇萃取低分子量物质，得到了具有良好的氧化热稳定性的有机硅材料。     

The characteristics and transfection efficiency of PEI modified by biodegradable poly(β-amino ester)

To improve the cytotoxicity of PEI25k and the transfection efficiency of poly(β-amino ester) with DNA, we synthesized a poly(β-amino ester), PEDP, bearing ester linkages in the backbone and tertiary amines in the backbone and side chain and prepared a binary mixture, PEDP–PEI25k, using physical blending meyhod. Both poly(β-amino ester) PEDP and binary mixture PEDP–PEI25k, readily self-assembled with plasmid DNA (pCMV-β gal) in a HEPES buffer, were characterized by dynamic light scattering. The results reveal that PEDP–PEI25k was able to self-assemble plasmid DNA into PEDP–PEI25k/DNA nano-complexes small enough to enter a cell through endocytosis. Titration studies were performed to determine the buffering capacities of PEDP and PEDP–PEI25k. The COS-7 cell viabilities in the presence of PEDP and PEDP–PEI25k were studied. At low mass ratio of PEDP/PEI25k (1/1), it is found that the transfection curve of PEDP–PEI25k/DNA bearing a maximum peak is similar to that of PEI25k/DNA. In addition, the PEDP–PEI25k/DNA complexes were able to transfect COS-7 cells in vitro with a high efficiency comparable to a well-known gene carrier PEI25k/DNA. The results indicate that binary mixture PEDP–PEI25k is an attractive cationic carrier for gene delivery and an interesting candidate for further study.     

Degradable poly(amino ester) based on poly(ethylene glycol) dimethacrylate and polyethylenimine as a gene carrier: molecular weight of PEI affects transfection efficiency

The aim of the research is to study the effect of polyethylenimine (PEI) molecular weight on the gene transfection efficiency of degradable poly(amino ester) based on poly(ethylene glycol) dimethacrylate (PEGDMA) and polyethylenimine (PEG-cr-PEI) as a gene carrier. Various low molecular weight (LMW) branched PEI based PEG-cr-PEI was synthesized via Michael addition. The degradation half-life of PEG-cr-PEI was longer at pH 5.6 than that at pH 7.4. The plasmid condensation and protection ability of the PEG-cr-PEI were confirmed by agarose gel electrophoresis assay. PEG-cr-PEI/DNA nanoparticles showed high positive zeta potential (>+20 mV), narrow size distribution, and spherical shapes with size below 250 nm when N/P ratios of PEG-cr-PEI to DNA were above 10, suggesting that they have endocytosis potential. The cytotoxicity of PEG-cr-PEI/DNA complexes was lower than that of PEI 25K/DNA complexes, and the transfections mediated by PEG-cr-PEI were checked in 293T, HeLa and HepG2 cell lines. The report gene expression was increased with increasing the molecular weight of LMW PEI. The “proton sponge effect” was proposed as the mechanism of PEG-cr-PEI mediated gene transfection.     

不同取代度氯甲基化聚醚酰亚胺的可控合成

采用无毒高活性的氯甲基辛基醚(CMOE)作为氯甲基化试剂,对聚醚酰亚胺(PEI)进行氯甲基化。考察了各种因素对氯甲基化反应的影响规律,优化了反应条件。溶剂用量、催化剂用量、反应温度等因素对反应有显著影响,最佳反应条件为:PEI∶CMOE∶C2H4Cl2∶ZnCl2=2.0 g∶4 mL∶50 mL∶1.0 g,反应温度60℃。在该条件下控制反应时间,成功合成了一系列不同取代度的氯甲基化PEI,取代度为21%~110%。     

聚醚酰亚胺中空纤维超滤膜的研究（I）膜结构、热性能和机械性能

以聚醚酰亚胺（PEI）为膜材料,聚乙烯吡咯烷酮（PVP）和聚乙二醇（PEG）等添加剂,N－甲基吡咯烷酮（NMP）和二甲基乙酰胺（PMAc)为溶剂,采用干／湿法纺丝技术制备出聚醚酰亚胺中空纤维膜,提高了PEI超滤膜的耐污梁性,通过改变纺丝液中不同的添加剂（如PEG或PVP）,PEI中空气纤维膜断面可从指状孔转变成海绵状,此外,讨论了聚醚酰亚胺中空纤维的膜结构,热性能和机械性能。     

A novel dendrimer based on poly (L-glutamic acid) derivatives as an efficient and biocompatible gene delivery vector

Non-viral gene delivery systems based on cationic polymers have faced limitations related to their relative low gene transfer efficiency, cytotoxicity and system instability in vivo. In this paper, a flexible and pompon-like dendrimer composed of poly (amidoamine) (PAMAM) G4.0 as the inner core and poly (L-glutamic acid) grafted low-molecular-weight polyethylenimine (PLGE) as the surrounding multiple arms was synthesized (MGI dendrimer). The novel MGI dendrimer was designed to combine the merits of size-controlled PAMAM G4.0 and the low toxicity and flexible chains of PLGE. In phosphate-buffered saline dispersions the well-defined DNA/MGI complex above a N/P ratio of 30 showed good stability with particle sizes of approximately 200 nm and a comparatively low polydispersity index. However, the particle size of the DNA/25 kDa polyethylenimine (DNA/PEI 25K) complex was larger than 700 nm under the same salt conditions. The shielding of the compact amino groups at the periphery of flexible PAMAM and biocompatible PLGE chains in MGI resulted in a dramatic decrease of the cytotoxicity compared to native PAMAM G4.0 dendrimer. The in vitro transfection efficiency of DNA/MGI dendrimer complex was higher than that of PAMAM G4.0 dendrimer. Importantly, in serum-containing medium, DNA/MGI complexes at their optimal N/P ratio maintained the same high levels of transfection efficiency as in serum-free medium, while the transfection efficiency of native PAMAM G4.0, PEI 25K and Lipofectamine 2000 were sharply decreased. In vivo gene delivery of pVEGF165/MGI complex into balloon-injured rabbit carotid arteries resulted in significant inhibition of restenosis by increasing VEGF165 expression in local vessels. Therefore, the pompon-like MGI dendrimer may be a promising vector candidate for efficient gene delivery in vivo.