Ionic conductivity and compatibility studies of blends of poly(methyl methacrylate) and poly(propylene glycol) complexed with LICF3SO3

Stable to atmospheric moisture, adhesive and transparent polymer electrolytes have been prepared by blending poly(methyl methacrylate) (PMMA) with poly(propylene glycol)-425/LiCF₃SO₃ complexes. The blending of the polymers has been achieved by a method developed in our laboratory: free radical polymerization of methylmethacrylate in the polyether/salt matrix. A series of polymer blend complexes varying in PMMA content (up to 20% by weight) and oxygen/metal ratios (25, 16, and 8) have been synthesized and their properties studied. All the samples prepared in this study were found to be optically clear unlike the higher molecular weight poly(propylene glycol)-2000 (PPG-2000) system which required a minimum salt concentration to compatibilize a specific amount of PMMA with PPG. The mechanisms by which the salt holds the otherwise incompatible polymers together in a single phase have been investigated by FT-IR. Our studies show a weak coupling of the ether oxygens in the PPG with the ester groups of the PMMA through the lithium cations. Discrete changes has been observed in the FT-IR spectrum of PMMA when doped with the lithium salt hitherto unnoticed with other dopants. Gel permeation chromatography results of the PMMA samples isolated from the solid electrolytes indicate the molecular weight to vary between 43000 and 121000 with relatively narrow distributions, 1.6?2.0. The ionic conductivities of the polymer blend electrolytes were fairly high (10^?5 S/cm) at room temperature. The PMMA neither significantly influenced the T_g of the blend complexes nor effected the ionic conductivities drastically. The ionic conductivity as a function of temperature followed the empirical Vogel-Tammann-Fulcher equation. The blending of PMMA with PPG/LiCF₃SO₃ complexes was found to impart good adhesiveness to the solid electrolytes while making them stable to atmospheric moisture. © 1992 John Wiley & Sons, Inc.     

Preparation,characterization and compatibility studies of poly(DFAMO/AMMO)

Poly(3-difluoroaminomethyl-3-methyl oxetane (DFAMO)/3-azidomethyl-3-methyl oxetane (AMMO)) (PDA) can be used as an energetic pre-polymer in the binder systems of solid propellants and polymer-bonded explosives (PBXs). The cationic solution polymerization affords PDA using butane diol (BDO) and boron trifluride etherate (TFBE) as initiator and catalyst, separately. Its molecular structure is characterized and thermal decomposition behavior is investigated by thermogravimetric analysis (TG), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). The copolymer has good thermal stability and exhibits a three-step mass-loss process with the first two steps mainly belonging to the thermal decomposition of difluoroamino and azido groups, respectively. DSC method is performed to evaluate the compatibility of PDA with some energetic components and inert materials. More than half of the selected materials are compatible with PDA, which including cyclotrimethylenetrinitramine (RDX), 2,4,6-trinitrotoluene (TNT), 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), pentaerythritol tetranitrate (PETN), ammonium perchlorate (AP), ammonium nitrate (AN), potassium nitrate (KNO₃), aluminum powder (Al), aluminum oxide (Al₂O₃), 2-nitrodiphenylamine (NDPA) and 1,3-diethyl-1,3-diphenyl urea (C₁).     

Investigation of the Compatibility of a Multi-Component TN Liquid Crystal Mixture and a Multi-Component Cholesteric Liquid Crystal Mixture by DSC

The phase transition curves of a multi-component TN liquid crystal mixture (TN 88-1) and a multi-component cholesteric liquid crystal mixture (Ch 88-2) were plotted by using a differential scanning calorimeter. The phase transition temperature and phase transition heat were obtained from the DSC curves. The results show that the components of TN 88-1 are compatible and they can form a stable mixture with CB 15 chiral liquid crystal. The components of Ch 88-2 are not compatible and Poly (MMA-BMA) can greatly improve their compatibility. This revised version was published online in July 2006 with corrections to the Cover Date.     

胆固醇-聚(D,L-乳酸)的制备及软骨细胞相容性研究

依据胆固醇对细胞膜良好的热力学亲和力及可以调节细胞膜磷脂双分子层的结构和动态行为的生理学的特点,采用本体聚合的方法制备了胆固醇-聚(D,L-乳酸),经GPC,1H-NMR分析证明产物分子量与理论分子量有较好的一致性,证明了聚合物的分子量可以通过调节D,L-丙交酯和胆固醇的量来控制.软骨细胞粘附率、增殖率以及3-(4,5-二甲基噻唑)-2,5-二苯基四氮唑溴盐(MTT)细胞活性的观测结果表明相比纯聚乳酸,胆固醇-聚乳酸明显促进了细胞的粘附与生长.通过激光共聚焦显微镜观察细胞形貌结果显示相比胆固醇-聚乳酸表面,纯聚乳酸表面的细胞数量较少且大多团聚没有正常铺展,而胆固醇-聚乳酸表面的软骨细胞则分布均匀,铺展充分.以上结果证明了胆固醇的存在有利于软骨细胞的生长和粘附,预示着胆固醇-聚乳酸在软骨组织工程以及其他相关的生物医疗领域有着广阔的应用前景.     

Thermal decomposition properties and compatibility of CL-20, NTO with silicone rubber

The new polycyclic nitramine 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIW) has been focused as a considerable amount of research recently on investigating its polymorphs, relative stability, and respective reaction chemistry. It is known as CL-20 popularly, CL-20 is a very high-energy and relatively high oxygen balance value crystalline compound whose method of synthesis and detailed performance data are still classified. 5-oxo-3-nitro-1,2,4-triazole (NTO, or nitrotriazolone) was an insensitive molecule comparison general explosives, and the NTO based polymer bonded explosives (PBX) was a low vulnerability explosive. Both energetic materials are all very important high explosives, which is used in a variety of military formulations widely owing to the properties of high energy and desensitization of PBX, many researchers have demonstrated the usefulness of above two energetic materials in explosive component. In this work, the thermal decomposition characteristics of explosives CL-20 and NTO were studied using thermal analytical techniques (TG, DSC), then the compatibility of above two explosives with silicone rubber, and the decomposition kinetic parameters such as activation energies of decomposition, the frequency factor of the decompose reaction are also evaluated by non-isothermal DSC techniques.     

Novel polymers based on atom transfer radical polymerization of 2‐methoxyethyl acrylate

Atom transfer radical polymerization (ATRP) has been employed in the polymerization of 2‐methoxyethyl acrylate (MEA) initiated by ethyl 2‐bromoisobutyrate in bulk or in toluene solution at 90–95 °C with the catalytic systems Cu(I)Br/PMDETA or HMTETA. Kinetics investigations revealed that ATRP of MEA proceeds in a controlled manner with a first‐order plot of monomer consumption, an almost linear molecular weight evolution and polydispersities < 1.29 in the entire conversion range. Well‐defined diblock copolymers with PMMA, PMEA‐b‐PMMA have been produced by use of both PMEA and PMMA macroinitiators, however, for the latter the controlled conditions were somehow difficult to maintain. The amphiphilic behavior of the diblock copolymers lead to phase separation resulting in two glass transition temperatures as detected by DSC. Contact angle (Θ) investigations with water on PMEA, PMMA, and diblock copolymers surfaces reveal PMEA as an intermediate hydrophilic with Θ ～ 50°, whereas PMMA and the diblock copolymers all fall in the hydrophobic region with Θ > 70°. © 2006 Wiley Periodicals, Inc. J Polym Sci Part Polym Chem45: 333–340, 2007     

聚乙烯醇／壳聚糖合金膜的相容性

本文通过 WAXD、DSC动态力学和应力一应变测量对 PVA/CS合金膜的聚集态结构进行了研究。发现,合金膜中的PVA结晶完善性变差,结晶度和结晶熔融峰温度随CS含量增加而降低。合金膜中的CS晶型发生了转化。动态力学损耗谱显示,合金膜中仍保持单组分的玻璃化松弛。当PVA含量大于50%％时,两个Tg峰中间产生一新的力学损耗峰。合金膜的模量和断裂强度高于单组分,而断裂伸长率低于单组分,这都表明,PVA与CS间存在强的相互作用,该共混体系为部分相容体系。     

（PSF—PDMS—PHS）n／PSF共混物的相容性及表面组成

利用ＤＳＣ、ＤＭＡ、ＴＥＭ和ＸＰＳ对［ＰＳＦ－ＰＤＭＳ－ＰＨＳ］ｎ／ＰＳＦ共混物的相容性及表面组成进行了研究．结果表明，ＰＤＭＳ在共混物表面的富集与ＰＳＦ均聚物和［ＰＳＦ－ＰＤＭＳ－ＰＨＳ］ｎ中硬段的相容性有关；ＰＤＭＳ在相容的共混物体系表面的富集与对应的多嵌段共聚物组成基本相近；不相容共混物体系表面ＰＤＭＳ的富集程度相对较高，当共混物本体中有机硅含量从１％增至５％，表面层ＰＤＭＳ的含量迅速增加，可达到嵌段共聚物中ＰＤＭＳ的含量．     

聚(ε-己内酯)/苯乙烯-丙烯腈共聚物共混物相容性的研究

本文采用DSC、IR方法研究了聚ε-己内酯PCL苯乙烯-丙烯腈共聚物SAN共混物的相容性。观察到共混物只表现出单一的玻璃化转变温度。而且随着含量的增加,半结晶高聚物的熔点下降,利用Flory-Huggins方程计算出共混体系的相互作用参数x_(23)计算结果表明该体系是热力学相容的。红外光谱的研究表明两种高聚物的这种相容性,是由于PCL中的羰基和SAN中的α-氢的氢键相互作用引起的。     

共混方法对聚氯乙烯/聚丙撑碳酸酯相容性影响

本文分别用溶液法和熔融法制得聚氯乙烯（PVC）与聚丙撑碳酸酯（PPC）共混试样，用DSC证明PVC／PPC共混物不相容，但它们不相容的程度受分子量、共混比例等因素的影响，并根据玻璃化转变温度（Tg）计算出溶液共混试样PPC富相中PVC的重量百分含量。NBR／PPC弹性体作偶联剂对PVC／PPC共混体系具有较好的增容作用，共混物中PPC的用量及分子量对共混体系性能有一定的影响。