Salts, solid-state polymerization

Later, Tieke reported the UV- and y-irradiation polymerization of butadiene derivatives crystallized in perovskite-type layer structures [21,22]. He reported the solid-state polymerization of butadienes containing aminomethyl groups as pendant substituents that form layered perovskite halide salts to yield erythro-diisotactic 1,4-trans polymers. Interestingly, Tieke and his coworker determined the crystal structure of the polymerized compounds of some derivatives by X-ray diffraction [23,24]. From comparative X-ray studies of monomeric and polymeric crystals, a contraction of the lattice constant parallel to the polymer chain direction by approximately 8% is evident. Both the carboxylic acid and aminomethyl substituent groups are in an isotactic arrangement, resulting in diisotactic polymer chains. He also referred to the y-radiation polymerization of molecular crystals of the sorbic acid derivatives with a long alkyl chain as the N-substituent [25]. More recently, Schlitter and Beck reported the solid-state polymerization of lithium sorbate [26]. However, the details of topochemical polymerization of 1,3-diene monomers were not revealed until very recently. 

Step-Grouch Polymerization Synthesis of a Polyurethane Foam Studies of Solutions and Gels Polymer Precipitation Gels from Alginic Acid Salts Solid State Properties... 

Polymeric sulfur lutride (or polythiazyl) (2) was first reported in 1910. It is prepared by the solid-state polymerization of S2N2 at 0°C over several days (see Section 5.1.3). The polymer is also obtained in high yield from the reaction of (NSC1)3 with trimethylsilyl azide in acetoiufrile or by the electrochemical reduction of S5N5+ salts. 

This article describes the solid state polymerization of 1,i-disubstituted butadiene derivatives in perovskite-type layer structures, in layered structures of organic ammonium halide salts, and in lipid layer structures. Recent investigations by spectroscopic methods and x-ray structure analyses are described. The studies clearly indicate that the photolysis in the crystalline state leads to the formation of 1,i-trans-polymers exclusively. Crystal structure analyses of monomeric and polymeric layer perovskites demonstrate that upon y-irradiation a stereoregular polymer is obtained in a lattice controlled polymerization. 

Figure 2.2 PA 6.5 production procedure. 1 PA 6.6 salt aqueous solution preparation, 2 solution-melt polymerization, and 3 solid-state polymerization.

Solid phase polymerization was considered by Flory [23] and has been variously pursued through the years [21]. Direct conversion of dry salt to solid polymer has not become important although increasing the molecular weight of polymer by solid state polymerization is a viable technique [24]. 

Melt Salts and Solid-State Polymerization. By using a chloroalu-minate melt obtained from a mixture of iV-acetylpyridinium chloride or Af-butylpyridinium chloride and AICI3 at room temperature, highly conducting poly(p-phenylene) films were obtained by electrooxidation of benzene on Ft [368-371]. 

Thermal polymerization of MCMs (with transition metal acrylates as examples) is of interest in at least two aspects. First, the stmcture of these salts contains many dislocations, that facilitate solid-state polymerization. Second, thermal decomposition and polymerization transformations are the stages for a potential method of the synthesis of polsnner-immobilized, highly dispersed nanosize metal particles. 

The salts containing polymeric anions in die solid state melt retain die anion stiiicture, e.g. and on melting, while die phosphates in which die... 

The solid-state structures of several benzylic carbanion salts have been elucidated by X-ray analysis9 depending on the nature of the benzylic part, the cation, and the additives, the structures range from er-bonded organometallic compounds to delocalized ion pairs, from monomeric to dimeric and polymeric aggregates. Some compounds are listed together with leading references ... 

Chromium zeolites are recognised to possess, at least at the laboratory scale, notable catalytic properties like in ethylene polymerization, oxidation of hydrocarbons, cracking of cumene, disproportionation of n-heptane, and thermolysis of H20 [ 1 ]. Several factors may have an effect on the catalytic activity of the chromium catalysts, such as the oxidation state, the structure (amorphous or crystalline, mono/di-chromate or polychromates, oxides, etc.) and the interaction of the chromium species with the support which depends essentially on the catalysts preparation method. They are ruled principally by several parameters such as the metal loading, the support characteristics, and the nature of the post-treatment (calcination, reduction, etc.). The nature of metal precursor is a parameter which can affect the predominance of chromium species in zeolite. In the case of solid-state exchange, the exchange process initially takes place at the solid- solid interface between the precursor salt and zeolite grains, and the success of the exchange depends on the type of interactions developed [2]. The aim of this work is to study the effect of the chromium precursor on the physicochemical properties of chromium loaded ZSM-5 catalysts and their catalytic performance in ethylene ammoxidation to acetonitrile. 

Solid-state synthesis of /J-nitrostyrenes has been reported by Varma et al. in a process that uses readily available styrene and its substituted derivatives and inexpensive clay-supported nitrate salts, clayfen and clayan (Scheme 6.50) [170], In a simple experiment, admixed styrene with clayfen or clayan is irradiated in a MW oven (-100-110 °C, 3 min) or heated in an oil bath (-100-110 °C, 15 min). For clayan intermittent heating is recommended with 30-s intervals to maintain the temperature below 60-70 °C. Remarkably, the reaction proceeds only in solid state and leads to the formation of polymeric products in organic solvent. 

The trimolybdates in the solid state are polymeric in nature (119, 120). Two different structure types are obtained as the potassium and rubidium salts K2[Mo3Oi0] and Rb2[Mo3Oi0] H20 shown in Fig. 14. The rubidium compound consists of a chain of Mo06 octahedra, whereas the potassium compound comprises edge-shared distorted Mo05 poly-hedra and Mo06 octahedra (121). 

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