BAMO/AMMO三嵌段共聚物的合成、表征及热分解动力学

以三氟化硼.乙醚/1,4丁二醇作引发体系,利用阳离子开环共聚合的方法合成出3,3′-双叠氮甲基环氧丁烷/3-叠氮甲基-3′-甲基环氧丁烷(BAMO/AMMO)三嵌段共聚物。用FTIR、1HNMR和GPC对共聚物的结构和相对分子质量进行了表征,用DSC测定了共聚物的玻璃化转变温度。结果表明,合成的BAMO/AMMO三嵌段共聚物的相对分子质量可控、且分布窄,并具有含能热塑性弹性体的性质。同时用Vyazovkin的非线性无模型函数方法研究其热分解动力学,得到叠氮基团的分解活化能约为150kJ/mol。三嵌段共聚物在叠氮基团分解之后形成了交联网络结构。     

MIR/NIR/FIR Characterization of Poly‐AMMO and Poly‐BAMO and their Precursors as Energetic Binders to be Used in Solid Propellants

To establish the relation between structure and properties of composite solid propellants it is important to know the structure of the elastomeric binder that has been used in the system. Therefore this study is focused on the characterization of polymers containing energetic groups that has been synthesized at ICT. The characterization uses the wide spectral band of infrared, NIR/MIR/FIR. This gives an identification of the analytical bands and allows quantitative and kinetic studies of these compounds.     

Preliminary Characterization of Propellants Based on p(GA/BAMO) and pAMMO Binders

In previous papers, the synthesis and characterization of OH‐terminated glycidyl azide‐r‐(3,3‐bis(azidomethyl)oxetane) copolymers (GA/BAMO) and poly‐3‐azidomethyl‐3‐methyl oxetane (pAMMO) by azidation of their respective polymeric substrates were described. The main objective was the preparation of amorphous azido‐polymers, as substitutes of hydroxy‐terminated polybutadiene (HTPB) in new formulations of energetic propellants. Here, the subsequent characterization of both the binders is presented. First of all, several isocyanates were checked in order to optimize the curing reaction, and then two small‐scale formulations of a propellant, based on aluminium and ammonium perchlorate, were prepared and characterized. Finally, the mechanical properties and burning rate were compared to those of a similar propellant based on HTPB as binder.     

聚1-丁烯热塑性弹性体的老化与防护

以拉伸性能为主要检测指标，考察了聚1-丁烯[P(1-Bt)]热塑性弹性体的热氧老化、紫外光老化和耐酸碱老化性能，制备了P(1-Bt)和三元乙丙胶(EPDM)防水卷材试样并进行对比：结果表明：单独使用抗氧剂1010，其用量在0．1～0．2质量份时具有较好的防热氧效果；1010与DLTP配合使用效果更佳，最佳配比为m(1010)：n(DLTP)=1：3(1010为0．2份)。热氧防老剂与紫外光吸收剂并用明显优于热氧防老剂或紫外光吸收剂单用时的防紫外光效果；ZnO对热氧老化和紫外光老化也具有很好的防护作用。P(1-Bt)制备的防水卷材的耐紫外光老化性能接近EPDM防水卷材，耐酸碱性能优于后者。     

Synthesis and Characterization of Poly(3‐azidomethyl‐3‐methyl oxetane) by the Azidation of Poly(3‐mesyloxymethyl‐3‐methyl oxetane)

Poly(3‐azidomethyl‐3‐methyl oxetane) (PAMMO) was prepared by the azidation reaction of poly(3‐mesyloxymethyl‐3‐methyl oxetane) (PMMMO), which was synthesized by cationic ring‐opening polymerization of MMMO for the first time. Two azidation reaction methods of PMMMO were considered to obtain PAMMO securely and efficiently. The thermal decomposition performance of PAMMO was studied by TG/FTIR/MS. The result of TG showed that the thermal decomposition of PAMMO involved two steps. Combined with FT‐IR and MS of the escaping gases to investigate the decomposition products of PAMMO, it is found that the first step was mainly corresponding to the thermal decomposition of azide group ( N₃), and the second step was mainly corresponding to the thermal decomposition of the polyether backbone.     

热塑性聚氨酯弹性体合金研究进展

热塑性聚氯酯是一类具有良好耐低温、高弹性和耐磨性能的新型弹性体。笔者综述了热塑性聚氯酯弹性体合金的研究进展，分析了国内热塑弹性体生产现状及未来的发展趋势。     

聚酯酰亚胺醚热塑性弹性体的合成及其纤维性能

采用一步法将偏苯三酸酐、乙二胺、乙二醇(或丁二醇)与聚四氢呋喃(相对分子质量1000)经熔融缩聚得到一系列不同软、硬段比例的聚酯酰亚胺醚热塑性弹性体。利用乌式黏度计和显微熔点仪测试了共聚物的特性黏数和熔点。将聚合物真空干燥后进行熔融纺丝、拉伸和热定形,测定了纤维样品的纤度、断裂强度、断裂伸长和回弹率。     

Influence of Different Woven Geometry in Poly(propylene) Woven Composites

Summary: The difference between the melting temperatures of poly(propylene) (PP) fibre and random poly(propylene‐co‐ethylene) (PPE) was exploited in order to establish processing conditions for an all PP composite. Under these conditions the matrix must be a liquid in order to ensure good wetting and impregnation at the fibres, though the temperature must not be too high to avoid melting the fibres. The high chemical compatibility of the two components allowed creation of strong physico‐chemical interactions, which favour strong interfacial adhesion. The static and dynamic mechanical properties and morphology of poly(propylene) woven fabric reinforced random PPE composites have been investigated with reference to the woven geometry that influenced the properties of the woven composites. Among the various cloth architectures that were used in the PP‐PPE composites, the satin weave imparted overall excellent mechanical properties due to the weave parameters, such as high float length and fibre count, low interlace point and crimp angle, etc. Morphology of the composite has been investigated by macro photography and scanning electron microscopy. Images from scanning electron microscopy provided confirmation of the above results by displaying the consolidation and good fibre‐matrix wetting of the composites.

Loss modulus of poly(propylene) woven‐matrix composites with different types of woven geometry.     

含规整 PMMA支链的 PBA合成及其力学性能

研究了聚甲基丙烯酸甲酯大单体与丙烯酸丁酯在苯中的共聚，该大单体由甲基丙烯酸甲酯在巯基乙酸链转移剂存在下聚合，用甲基烯酸缩不甘油酯封端，研究了共聚速率、大单体相对分子质量、大单体与小单体投料比、引发剂用量、单体浓度及共聚温度对接枝效率及共聚物相对分子质量的影响。用分级沉淀法精制共聚物。用凝胶渗透色谱法、红外光谱法及差示扫描量热法对共聚物进行表征，用蒸汽压式渗透压力计及膜渗透压测定了结构参数，结果表明，平均接枝数随转化率增加而降低，在一定的组成范围内，共聚物呈热塑性弹性体行为。     

陈化方式对负载钛催化合成聚1-丁烯的影响

以TiCl4(简称Ti)／Al(i-Bu)3(简称A1)为催化剂,合成了聚1-丁烯热塑性弹性体,考察了催化剂的陈化温度、陈化时间以及陈化1-丁烯(Bt)用量对转化率、聚合物重均相对分子质量的影响。结果表明．采用0℃下Ti-Al-Bt三元陈化方式制备的催化剂可以有效地提高单体的转化率,降低Al的用量。最佳陈化条件为：Bt／Ti(摩尔比)60,Al／Ti(摩尔比)20,0℃,20min。0℃陈化时,试样的重均相对分子质量比室温陈化的高;三元陈化试样的重均相对分子质量比二元陈化的高。在室温和0℃陈化时．陈化时间较短,试样的重均相对分子质量变化不大;随陈化时间的延长,试样的重均相对分子质量下降。     

Compatibilisation of various PLA/thermoplastic elastomer blends with diisocyanate coupling agent

Poly(lactic acid) (PLA) is characterised by its inherent brittleness, a detrimental feature for the production of durable bioplastics. PLA has been toughened by a low amount (12?wt-%) of various thermoplastic elastomers (TPE) including poly(ether-b-ester) (PEEs), poly(ether-b-amide) (PEBA) and poly(ether-b-urethane) (PEU). PLA–TPE blends were prepared by using a twin screw extruder. Ductility and impact resistance can be slightly improved with the incorporation of TPEs but but PEBA appears the most efficient. Reactive compatibilisation has been performed with the addition in the melt of a low amount (2?wt-%) of 4,4-methylene diphenyl diisocyanate. All compatibilised blends exhibit high toughness with similar ductility. These blends preserve good stiffness and high tensile strength. Compatibilised PEBA blends can be considered as super tough poly(lactic acid) materials. This work confirms that the flexibility of the elastomer together with the quality of the interfacial adhesion between the rigid (PLA) and the soft (TPE) phases are the primary factors influencing the toughness.     

用转矩流变仪调节聚氯乙烯/废胶粉热塑性弹性体的加工配方

用转矩流变仪对聚氯乙烯/废胶粉热塑性弹性体的加工温度、加工转速、交联剂用量、增塑剂的种类与用量以及增容剂用量进行了调节。结果表明,用流变仪研究加工配方可以确立加工的最佳工艺参数。选择加工温度在160℃、加工转速为50 r/m in时,安全加工时间适中,且能耗较低。采用促进剂TT硫化体系,当氧化锌用量(质量分数,下同)为4%~6%、促进剂TT为1.6%~2.4%、硫黄为1.6%~2.4%时,材料的性能较好。选用邻苯二甲酸二丁酯为增塑剂,共混体系的流动性能较好,加工能耗较低,且增塑剂用量为24%~30%较为适宜。选用丁腈橡胶作增容剂,当其用量为4.90%~7.91%时,有利于提高聚氯乙烯与废胶粉之间的界面结合,用量过大会使共混体系的加工性能大幅度下降。     

POE-g-(GMA-Co-St)的制备及其对PBT的共混改性

采用熔融接枝的方法成功制备了苯乙烯与甲基丙烯酸高水甘油酯的共聚物接枝聚烯烃热塑性弹性体[POE-g-(GMA-Co-St)],并以此对聚对苯二甲酸丁二醇酯(PBT)进行改性,研究了POE-g-(GMA-Co-St)含量对PBT力学性能、结构以及熔融结晶行为的影响。结果表明:POE-g-(GMA-Co-St)可显著提高PBT的冲击强度,同时随着POE-g-(GMA-Co-St)含量的增加,POE-g-(GMA-Co-St)在PBT基体中的尺寸更小,PBT的结晶度逐渐降低。     

The Properties of Sepiolite Nanofibers Reinforced Polycarbonate/Poly(acrylonitrile-butadiene-styrene) Composites Using a PS-co-MAH Compatibilizer

We prepare polycarbonate/poly(acrylonitrile-butadiene-styrene) composites which are reinforced with sepiolite nanofibers and use a polystyrene-maleic anhydride copolymer for improving polycarbonate/poly(acrylonitrile-butadiene-styrene) compatibility. By measuring glass transition temperatures and morphologies, we conclude that the copolymer effectively improves the compatibility. Further, polycarbonate/poly(acrylonitrile-butadiene-styrene) composites containing various amounts of sepiolite are prepared. It is found that the surface-modified sepiolite nanofibers are well-dispersed in the polymer matrix, and the mechanical properties and heat resistance are increased with the sepiolite contents increasing. The influences of sepiolite nanofibers on the melt flowability are also investigated. With these results, the composite with the optimum properties is provided.     

Structure–property relationships of lightly chemical crosslinked poly(vinyl chloride) thermoplastic elastomer

Chemical crosslinked poly(vinyl chloride) (C‐PVC) was synthesized by vinyl chloride suspension polymerization in the presence of diallyl phthalate (DAP) and plasticized to prepare poly(vinyl chloride) (PVC) thermoplastic elastomer (TPE) materials. The chemical crosslinking and physical crosslinking structure in chemical crosslinked PVC‐TPE were investigated. It showed that the gel fraction and the crosslinking density of gel increased as the feed concentration of DAP increased. C‐PVC prepared by VC/DAP copolymerization was lightly crosslinked as compared with irradiation crosslinked PVC. Physical entanglements would greatly influence the crosslinking density of gel when the gel fraction was high. Chemical crosslinking had little influence on the recrystallization behavior of PVC. A structure model of chemical crosslinked PVC‐TPE was proposed, in which chemical networks acted with physical networks cooperatively. It also showed that chemical crosslinking and physical crosslinking influenced the processability and mechanical properties of chemical crosslinked PVC‐TPE cooperatively. Although the processability of PVC‐TPE deteriorated with chemical crosslinking, the dimension stability and elasticity of PVC‐TPE were improved as the permanent chemical networks were introduced. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 868–874, 2000     

Preparation,characterization, and properties of crosslinked hydroxylated poly(styrene‐b‐butadiene‐b‐styrene) triblock copolymer

Acrylic acid was crosslinked with N,N′‐methylenebisacrylamide and converted to bioactive hydrogels by neutralization with different amino containing compounds. Several amino containing compounds were used such as 2‐aminopyridine, triethanol amine, hexamethylenetetramine (HMTA), pyridine, and imidazole. The best crosslinker ratio was determined in addition to the maximum absorbed water in different mediums. The antibacterial activity of the prepared gels were examined against examples of Gram‐positive (Staphylococcus aureus) and Gram‐negative bacteria (Escherichia coli) using agar plate method. The study was extended by evaluating one of prepared gels in columns as models for water filters. All prepared gels showed antibacterial action in agar plate method against both bacterium and the column method using one of the prepared gels showed excellent filtration and biocidal action. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

纳米Pd/P(AAEM-St)复合材料的制备与表征

超声引发乳液聚合制备了纳米钯/乙酰乙酸基甲基丙烯酸乙酯-苯乙烯共聚物[Pd/P(AAEM-St)]复合材料,研究了复合材料的结构及热稳定性。XRD结果表明Pd2+被还原成了Pd粒子,FTIR结果表明纳米粒子与聚合物基体之间存在相互作用,TG结果表明纳米粒子的存在对P(AAEM-St)基体的热稳定性有一定影响。     

Synthesis, crystallization and tensile properties of poly(ethylene terephthalate-co-2,6-naphthalate)s with low naphthalate units content

A series of poly(ethylene terephthalate-co-naphthalate)s (PETN copolymers) with low naphthalate units content was synthesized. A melting point depression was observed, while the glass transition temperatures were slightly higher than that of Polyethylene terephthalate (PET). Crystallization rates of the copolymers decreased with increasing comonomer content. WAXD patterns showed that only PET crystals were formed. Co-crystallization behaviour was evaluated on the basis of the Wendling–Suter model. The tensile properties of the copolymers PETN 97/3 and PETN 94/6, Young's modulus yield stress and elongation at break was significantly improved compared to PET. WAXD showed that some crystalline precursor was generated during drawing of the specimens. DSC traces of the drawn specimens showed enhanced crystallization rates compared to that of the original amorphous specimens.     

间苯二甲酸改性聚醚酯弹性体的合成与表征

用间苯二甲酸(IPA)作为改性剂,对以对苯二甲酸二甲酯(DMT),1,4–丁二醇(BDO),聚四氢呋喃醚(PTMG)和抗氧剂1010为原料以及钛酸丁酯为催化剂合成的软硬段为7∶3的聚醚酯弹性体进行改性,以提高其纤维的低温回弹性能。通过改变IPA与DMT的物质的量比(1∶5~1∶15),成功地合成了一系列的IPA改性聚醚酯弹性体(PBITG–1~PBITG–5),并对其结构、热性能、力学性能和纤维回弹性能进行了测试和表征。通过对IPA改性聚醚酯弹性体的傅立叶变换红外光谱和核磁谱图分析可知,成功地合成了IPA改性聚醚酯弹性体。从差示扫描量热测试结果分析得知,随着IPA含量的降低,所合成的IPA改性聚醚酯弹性体的熔点逐渐增加。热重分析结果表明,不同IPA含量的聚醚酯弹性体都具有良好的热稳定性能,起始分解温度都高于365℃。通过单纤强力仪测试表明,同一拉伸倍数下,随着IPA含量的减少,聚醚酯弹性体纤维的断裂强度和断裂伸长率都有所增加。低温回弹性能测试结果表明,IPA的加入的确能提高聚醚酯弹性体纤维的低温回弹性能,其中,PBITG–1纤维拉伸1倍时对应的低温回弹率最大,为97.92%。     

Influence of soft segment content and chain length on the physical properties of poly(ether ester) elastomers and fabrication of honeycomb pattern and electrospun fiber

Different series of poly(ether ester) (PEE) thermoplastic elastomers were synthesized using dimethyl-2,6-naphthalene dicarboxylate as hard segment, 1,4-butanediol as the chain extender, and three different soft segments of different molecular weights (MW), namely polycaprolactone diol (MW: 530 and 2000), poly(tetramethylene ether glycol) (MW: 1000 and 1800), and polycaprolactone-block-polytetrahydrofuran-block-polycaprolactone (MW: 2000). The composition of soft segment was changed from 30% to 50% with respect to the hard segment. The characteristic studies were focused to analyze the influence of the concentration and length of the soft segment content. In each series, 50:50 compositions of the hard and soft segments were found to show the best mechanical properties. In addition the physical properties of the elastomer were very sensitive to the type of soft segment. The elastomers prepared in this study were systematically characterized using various spectroscopic studies and thermal and mechanical analyses. As a means of discovering the feasibility of PEE elastomers as new functional materials honeycomb patterns and nanofibers have been fabricated by applying breath figures method and electrospinning, respectively, yielding uniform honeycomb structures and nanofibers of their diameter ranging from about 100 to 800 nm depending on the type of elastomer and the electrical potential employed .