John D. Yeager;Virginia W. Manner;Jamie A. Stull;David J. Walters;Andrew M. Schmalzer;Darby J. Luscher;Brian M. Patterson
会议集名/来源：Shock Compression of Condensed Matter - 2017, Part A: Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter.St. Louis, MO(US).9-14 July 2017
Cast-cure formulations of plastic-bonded explosives (PBX) present some advantages in manufacturing and application compared to traditional pressed slurry formulated materials. For example, these formulations can be cast to specific shapes and then cured in place, avoiding the need for machining precision parts. However, the microstructure of these materials can be greatly affected by the specific manufacturing process. Here, we evaluate the effect of minor changes to the formulation and manufacturing process on several cyclotetramethylene-tetranitramine (HMX) PBXs. The binders were based on hydroxyl-terminated polybutadiene (HTPB) and cast-cured using diphenylmethane diisocyanate (isonate) as a curing agent. We examined the materials using X-ray computed tomography (CT) imaging and uniaxial compression testing. The isonate content was found to significantly affect the modulus and strength of the binder. The presence of significant void content could be controlled by adding a centrifuging step during the curing process, but the resulting effect on mechanical properties was relatively minor. Mesoscale simulations showed that differences in the mechanical strength of the binder were not sufficient to describe the differences observed in mechanical testing, indicating that the HMX-binder adhesion was also being changed by the manufacturing process.
Diphenylmethane is an important substructure unit that is found not only in a number of natural products, but also in many synthetic compounds of biological and pharmaceutical importance. Significant efforts are devoted to the construction of this motif and its derivatives, and diverse synthetic methods, roughly classified as conventional and catalytic ones, have been reported so far. In this article, we described a first example for the synthesis of symmetrical diarylmethanes by facile, one-pot, two-step, palladium-catalyzed sequential coupling(Scheme 1). In the facile one-pot reaction, aryl methyl ketone acts in formal as the methylene donor. The experimental facts, including TLC monitoring, speculated intermediates as the raw materials, ex situ IR spectroscopy analysis of the co-product cesium benzoate, as well as the cross-coupling reactions of two different aryl halides, indicate a mechanism involving a palladium-catalyzed sequential two-step coupling process. The reaction is applicable for a broad spectrum of substrates(up to 21 examples) in good to excellent yields. The access to unsymmetrical diarylmethanes with this method is also explored and various factors are discussed.
会议集名/来源：Proceedings of 2013 International Conference on Intelligent Materials and Mechatronics(IMM 2013)
Fluorinated polyurethanes(FPU) was prepared using fluorinated polyether polyol(FPO) as the soft segment, 4,4`-diphenylmethane diisocyanate(MDI) as the hard segment, 1,4-butanodiol(BDO) as the chain extender and catalysts. Tin metal catalysts were used to catalyze the polyurethane reaction of polyether polyols and isocyanate. The effect of different catalysts including stannous octoate(T-9) and dibutyltindalautrate(DBTDL) on the structure, surface properties and thermal properties of FPU was studied. The structural elucidation of the synthesized FPU was performed by Fourier transform infrared(FT-IR) and discovered that with decreasing catalyst efficiency or without catalyst, the strength of hydrogen bounds were enhanced. The FPU films surface was characterized by contact angle(CA) and atomic force microscopy(AFM) and it was found that the phase separation was increasing with increasing catalyst efficiency. The thermal property was exhibited by Thermo gravimetric(TG) and showed that joining catalyst improved stability significantly.
会议集名/来源：Proceedings of 2015 International Conference on Power Electronics and Energy Engineering（PEEE 2015-1）
Segmented polyether-polyester polyurethanes with an amorphous hydrophilic soft segment phase were prepared from 4,4'-diphenylmethane diisocyanate(MDI),polybutylene adipate glycol 2000(PBA2000) and polyethylene glycol 1000(PEG1000) with 1,4-butanediol(BDO) as the chain extender.Furthermore,the micro phase separation structure of the polyurethanes was studied.The studies show,the micro-structure of nonionic polyurethane has been remarkable influenced by the structure,molecule and concentration of its soft segments.
Auramine O(AuO)is a derivative of diphenylmethane cationic fluorescent dye,which is used to study the complexation properties of the host molecules,such as cyclodextrins1 and calixarene sulfonates.2 The host-guest interaction between Auramine O and Cucurbit[n]uril3 has been investigated in aqueous solutions.The studies suggest simultaneous formation of 1:1