Polymer synthesis thermal stability

Lam JWY, Chen J, Law CCW, Peng H, Xie Z, Cheuk KKL, Kwork HS, Tang BZ (2003) Silole-containing linear and hyperbranched polymers synthesis, thermal stability, light emission, nano-dimensional aggregation, and optical power limiting. Macromol Symp 196 289-300... 

Keywords Hydroboration of Vinylchlorosilanes / Preceramic Polymers / Polyborosilazane / Thermal Stability / Synthesis... 

Table 11 describes the thermal properties of polyether sulfone based on DCDPS and heteroarylenediol. The TgS range from 230 to 315°C and the decomposition temperature is higher than 450°C. Their thermal stability depends on the bisphenol and activated difluoride used in the polymer synthesis (Tables 10 and 11). 

Polyimide-clay nanocomposites constitute another example of the synthesis of nanocomposite from polymer solution [70-76]. Polyimide-clay nanocomposite films were produced via polymerization of 4,4 -diaminodiphenyl ether and pyromellitic dianhydride in dimethylacetamide (DMAC) solvent, followed by mixing of the poly(amic acid) solution with organoclay dispersed in DMAC. Synthetic mica and MMT produced primarily exfoliated nanocomposites, while saponite and hectorite led to only monolayer intercalation in the clay galleries [71]. Dramatic improvements in barrier properties, thermal stability, and modulus were observed for these nanocomposites. Polyimide-clay nanocomposites containing only a small fraction of clay exhibited a several-fold reduction in the... 

Another example of interesting new inorganic polymers is found in the work of Lasocki (p. 166), who reports the synthesis of polysilazoxanes, -[(R.SiO) (I SiNR) ] and finds surprisingly better thermal stability compared wltfi their polysiloxane analogs. 

Andrianov and Zhdanov have developed a method for the synthesis of polymers containing heterochain and carbon-chain units by free-radical copolymerization of metal-containing polyorganosiloxanes bearing a pendant vinyl group with vinyl monomers. The copolymers thus obtained display increased thermal stability and can be used for the production of laminated plastics, adhesives and other valuable materials 53),... 

The synthesis of block polymers of diacetylene-silarylene and diacetylene-carboranylenesiloxane polymers (99a-e) (Fig. 61) by the polycondensation reaction of 1,4-dilithiobutadiyne with l,4-bis(dimethylchlorosilyl) benzene and/or l,7-bis(tetramethylchlorodisiloxane)-m-carborane have been reported by Sundar and Keller.129 These polymers are a hybrid between the carboranylenesiloxane and silarylene-siloxane polymers and have high char yields (up to 85%) at 1000°C in N2 and in air, reflecting the thermal stabilizing effects of the carborane and aromatic units in the polymeric backbone. 

Ando and co-workers have reported the synthesis of a silyl-carborane hybrid diethynylbenzene-silylene polymer (108) (Fig. 66) possessing high thermal stability.136 The polymer contained Si and —C=C— group in the main chain and m-carborane and vinyl groups in the side chain. The 5% weight-loss temperature of the cured polymer in air was over 1000°C as determined by thermogravimetric analysis. 

Herein we present the synthesis of two series of fluorinated acrylate polymers and copolymers derived from commercially available hexafluoro-2-hydroxy-2(4-fluorophenyl)propane. The solubility, film-forming ability, thermal stability, and water absorption in these polymers have been studied. 

The formation of carbon-carbon bonds using olefin metathesis methodology is a powerful technique in fine organic synthesis and polymer chemistry. The increasing importance of these reactions is reflected by the numerous publications over the last few years. Many of these pubhcations deal with the design and apphca-tion of polymer-supported olefin metathesis catalysts with the aim to overcome the common drawbacks of the homogeneous catalysts low thermal stability and difficulties associated with their recovery from the reaction mixtures. The modem state of art in this important field is described in chapter 11 of this volume. 

Three poly(aryl ethers) were prepared and used as coblocks in imide copolymerizations. The first coblock prepared was poly(aryl ether phenylquinoxaline), since this material has the requisite high Tg ( 280 °C) and thermal stability, and the polymer can be processed from solution or the melt. The synthesis of po-ly(aryl ether phenylquinoxalines) involves a fluoro-displacement polymerization of appropriately substituted fluorophenylquinoxalines with bisphenols, us-... 

The drive for the synthesis and characterization of synthetic coordination polymers was catalyzed by work supported and conducted by the U.S. Air Force in a search for materials which exhibited high thermal stabilities. Attempts to prepare highly stable, tractable coordination polymers were disappointing. Typically, only oligomeric products were formed and the monomeric versions were often more stable than the polymeric versions. 

Abstract Synthesis of carbon adsorbents with controlled pore size and surface chemistry adapted for application in medicine and health protection was explored. Conjugated polymers were used as carbon precursors. These polymers with conjugated double bonds C = C have high thermal stability. Formation of sp carbon structures occurs via condensation and aromatization of macromolecules. The structure of carbon materials obtained is related to the structure of the original conjugated polymer, thus the porous structure of carbon adsorbents could be controlled by variation of the conjugated polymer precursor. 

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