Poly /modified carbonate

The principal classes of high performance fibers are derived from rigid-rod polymers, gel spun fibers, modified carbon fibers, synthetic vitreous fibers, and poly(phenyiene sulfide) fibers. 

The use of backbone-modified poly (amino acids) as biomaterials was first suggested by Kohn and Langer (17) who prepared a polyester from N-protected trans-4-hydroxy-L-proline, and a poly(itiuno-carbonate) from tyrosine dipeptide as monomeric starting material (12,18). 

The majority of those involved in research on siloxane-modified poly(arylene carbonates) have chosen to synthesize copolymers of arylene carbonates and polysiloxanes (2-17). 

In this research three synthetic approaches leading to siloxane-modified poly(arylene carbonates) were investigated ... 

Polycondensation of Bisphenols, II, with Phosgene. Polycondensation of siloxane-linked bisphenols, II, with phosgene is the most obvious synthetic approach leading to siloxane-modified poly(arylene carbonates) since the phosgene-bisphenol polycondensation is used in the synthesis of aromatic polycarbonates (1). This method was used initially to prepare polymer (as indicated in reaction 1) as well as for the attempted synthesis of polymers 2 and 5 ... 

Heteropolycondensation of Bis-silanols, III, with Diacetoxysilanes. Heteropolycondensation of bis-silanols, III, was investigated since this approach appeared to offer a relatively rapid preparative route to a number of various siloxane-modified poly(arylene carbonates) which were required in order to obtain structure-properties correlations for such polymers. 

It was found that the reaction conditions which were optimized for the synthesis of poly(arylene siloxanylenes) (43) could be employed for the synthesis of siloxane-modified poly-(arylene carbonates). 2,4,6-Trimethylpyridine (collidine) was selected as the most suitable of all catalysts investigated (43) for the synthesis of the siloxane modified poly(arylene carbonates). Properties of polymers prepared by this method are given in Table I. In comparision to the phosgene-catalyzed homo-polycondensation of bis-silanols, III, the inherent viscosities... 

At the other end of the temperature spectrum, with high thermal stability of siloxane-modified poly(arylene carbonates) also a desired property, the onset of thermal decomposition (40) for polymers 1-12 was found to be in the range of 385-456°C (as determined from TGA curves obtained by heating polymer samples in nitrogen at a heating rate of 20°C/min.). There does not appear to be any pronounced trend in regard to variation of the thermal stability with structure in polymers 1-12. The small differences in the values of T for these polymers can be due... 

M.J. Lobo-Castanon, A.J. Miranda-Ordieres and P. Tunon-Blanco, A bienzyme-poly-(o-phenylenediamine)-modified carbon paste electrode for the amperometric detection of L-lactate, Anal. Chim. Acta, 346(2) (1997) 165-174. 

Patents on poly(ester-imide) resins where one of the components is ethylene carbonate [54, 55] or an imide modified linear poly(ethylene carbonate) [56] also exist. In another case the carbonate group is introduced into the molecule using diphenylcarbonate via transesterification reaction [57]. 

Pauliukaite, R., Ghica, M.E., Barsan, M., Brett, C.M.A. Characterisation of poly(neutral red) modified carbon film electrodes application as a redox mediator for biosensors. J. Solid State Electrochem. 11, 899-908 (2007)... 

This review presents the syntheses of different analogs of sucrose. Transformations of this di-saccharide at the terminal positions (Cl, or C6, or C6 ) provide modified sucroses such as amines, uronic acids, thiols, or phosphorus derivatives. Preparation of so-called higher sucroses i.e. derivatives in which the terminal positions are elongated by a poly-hydroxylated carbon chain is also reviewed. Special attention is directed to the synthesis and properties of macrocyclic derivatives crown- and aza-crown ethers with sucrose scaffold. Such macrocyclic receptors exhibit interesting complexing properties towards chiral ammonium salts. 

Until 2003, Chen s [28], Qu s [29-31], and Hu s [32] groups independently reported nanocomposites with polymeric matrices for the first time the. In Hsueh and Chen s work, exfoUated polyimide/LDH was prepared by in situ polymerization of a mixture of aminobenzoate-modified Mg-Al LDH and polyamic acid (polyimide precursor) in N,N-dimethylactamide [28]. In other work, Chen and Qu successfully synthesized exfoliated polyethylene-g-maleic anhydride (PE-g-MA)/LDH nanocomposites by refluxing in a nonpolar xylene solution of PE-g-MA [29,30]. Then, Li et al. prepared polyfmethyl methacrylate) (PMMA)/MgAl LDH by exfoliation/adsorption with acetone as cosolvent [32]. Since then, polymer/LDH nanocomposites have attracted extensive interest. The wide variety of polymers used for nanocomposite preparation include polyethylene (PE) [29, 30, 33 9], polystyrene (PS) [48, 50-58], poly(propylene carbonate) [59], poly(3-hydroxybutyrate) [60-62], poly(vinyl chloride) [63], syndiotactic polystyrene [64], polyurethane [65], poly[(3-hydroxybutyrate)-co-(3-hydroxyvalerate)] [66], polypropylene (PP) [48, 67-70], nylon 6 [9,71,72], ethylene vinyl acetate copolymer (EVA) [73-77], poly(L-lactide) [78], poly(ethylene terephthalate) [79, 80], poly(caprolactone) [81], poly(p-dioxanone) [82], poly(vinyl alcohol) [83], PMMA [32,47, 48, 57, 84-93], poly(2-hydroxyethyl methacrylate) [94], poly(styrene-co-methyl methacrylate) [95], polyimide [28], and epoxy [96-98]. These nanocomposites often exhibit enhanced mechanical, thermal, optical, and electrical properties and flame retardancy. Among them, the thermal properties and flame retardancy are the most interesting and will be discussed in the following sections. 

Monoamine oxidase amperometric biosensor based on SPE were also modified with MWCNT by using the drop casting technique for the determination of antidepressants in model solutions and dosage forms. The authors used BSA protein which provided a matrix for the immobilization of the enzyme and protection of the enzyme activity when glutaraldehyde is used as a linker. Serafin et aZ. developed a label free dual immunosensor for the determination of human growth and prolactin hormones. The electrochemical immunosensor was based on CNT modify carbon SPE platform with the presence of poly(ethylene-dioxythiophene) (PEDOT) and gold nanoparticles. Again, the hybrid nano-material composite facilitated a proper immobilization of the antibody on the electrode matrix. 

Applications of Raman to polymer/additive deformulation are still rather few, especially if compared to IR methods (cfr. Chp. 1.2.1). Hummel [108] has attributed the general lack of applications of RS in the field of plastics additives to poor Raman scattering of certain substance categories, unsatisfactory reproducibility of the spectra and scarcity of specific Raman libraries [385,386]. Polymer/additive analysis by means of Raman spectroscopy is mainly restricted to fillers, pigments and dyes the major usefulness comes from NIR FT-Raman, which greatly overcomes the fluorescence problem. The ion-pair dissociation effect of the 2-keto-4-(2,5,8,11-tetraoxadodecyl)-l,3-dioxolane modified carbonate (MC3) plasticiser in poly(ethylene oxide) (PEO) was studied by means of Raman, FTIR and EX-AFS [387]. Another study established the feasibility of using Raman spectroscopy to quantify levels of melamine and melamine cyanurate in nylons [388]. 

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