Silylated bisphenols

Condensation with activated chloroaromatics with O-silylated bisphenols in NMP in presence of K2CO3 has also been reported by Kricheldorf and Jahnke [103]. The... 

The 0-silylated bisphenol monomer is stable at high temperature, and can act as a good nucleophile beyond certain temperature. 

Polyphosphates are also an important class of organophosphorus polymers. In addition to their flame-retardant characteristics, they possess attractive plasticizing properties and can be used as polymeric additives to other polymers [123-128]. In general, polyphosphates can be prepared by interfacial [119,129], melt [130], or solution polycondensation [131,132a,b]. Kricheldorf and Koziel [133] prepared polyphosphates from silylated bisphenols. 

Kricheldorf, H. R., Bier, G. (1984). New polymer synthesis 11 Preparation of aromatic poly (ester ketones) from silylated bisphenols, 25(8), 1151-1156... 

Kricheldorf and Bier used cesium fluoride as the catalyst for the bulk polymerization of various silylated bisphenols and 4,4 -diflu-orobenzophenone at elevated temperatures from 220 to 320°C (18). The polymerization is essentially a nucleophilic aromatic substitution. Transetherifications were not found during the course of... 

Hans R. Kricheldorf and Gerhard Bier. "New polymer syntheses II. preparation of aromatic poly(ether ketone)s from silylated bisphenols." Polymer, pp. 1151-1156,1984. 

Alternatively, the bistrimethylsilyl ethers of the bisphenols can be used instead of the alkali salts. This approach has the advantage, since the formation of water and, thus, the risk of a hydrolytic cleavage of C-F bonds is avoided. Furthermore, the purification of the silylated bisphenols can be achieved by simple vacuum distillation. The use of silylated bisphenols also aUows for the preparation of poly(arylene ether)s in the melt (T 130-300 °C) in the presence of catalytic amounts of CsF or KF, thus, avoiding the removal of large amounts of inorganic salts and solvents [94-96] (Fig. 19C). 

Lakshmi et al. [303],Meier-Haacketal. [302], andTaegeretal. [301] used the sUyl method for the preparation of suUbnated poly(arylene ether sulfone)s. Like Shin et al. [285], these authors used hydroquinone sulfonic acid as a source for the proton exchange group. Polymers were prepared from the more reactive 4,4 -difluorodiphe-nylsulfone rather than 4,4 -dichlorodiphenylsulfone and various silylated bisphenol comonomers, such as hydroquinone, phenolphthalein, 2,6-dihydroxynaphthalene, bisphenol A [303], or 4,4 -dihydroxybiphenyl [301-303]. The use of silyl ethers and difluoro aromates allows for lower reaction temperatures (150 °C), as in the case of dichloro aromates and free bisphenols (180-190 °C). In the latter case, the water formed has to be removed by azeotropic distillation and the lower reactivity of the dichloro compound has to be taken into account. 

Most FRs can be analyzed with GC without derivatization. Eor some of the analytes, however, derivatization can improve its GC analysis. Eor brominated and chlorinated derivatives of bisphenol A, for example, a silylation step using A,G-bis(trimethylsilyl)trifluoroacetamide as reagent can be carried out after clean up. Phenolic compounds, such as TCBPA, TBBPA, and brominated phenols, can also be methylated with, e.g., diazomethane. ... 

Two grades of fumed silica with a different degree of surface treatment and different polarity have been used a nontreated, hydrophilic Wacker HDK N20 (BET surface area 200 nP/g, 1.8 SiOH/nm equivalent to 100 % residual SiOH) and a fully silylated hydrophobic Wacker HDK H18 (carbon content 4.5 % C, 15 % residual SiOH), the latter being covered by a chemically grafted PDMS layer. Both silicas are products finom Wacker-Chemie GmbH, Germany. The resins used are an unsaturated polyester resin Palatal P4 (UP resin), a co-condensate of a diol, maleic acid and orthophthalic acid, and the vinyl ester resin Atlac 590 (VE resin), a co-condensate of glycidine, methacrylic acid and bisphenol A. Both resins have a styrene content of 35 % and are provided by DSM, The Nertherlands. 

Omega-SLllyl polycarbonates have been hydrosilated with either tertiary silanes or ym-tetramethyldisiloxane to yield silylated polycarbonates or polycarbonate-disiloxane-polycarbonate triblock copolymers.The siloxane-containing polymers exhibit relatively lower Tg and higher thermooxidative stability compared with bisphenol A polycarbonate. Hydrosilation of allyl-terminal poly(alkyleneoxide-co-sulfone) in 1 1 or 2 1 ratio with hydride-terminal polysiloxane leads to ABC and (AB)2C type block-terpolymers, respectively. DSC studies indicate microphase separation, while TGA data point to higher thermal stability for the siloxane... 

Materials 3-Hydroxy-, 3,5-dihydroxy, 3-amino- and 3,5-diaminobenzoic acid were gifts of BAYER AG (Leverkusen, FRG) and used without further purification. Bisphenol-P and bisaniline-P were purchased from Kennedy and Klim (Little Silver, N.J., USA). Piperazine, l,l,l-tris(4 -hydroxy-phenyl)ethane, phloretic acid tetrahydroxy spirobisindane were purchased from Aldrich Co. (Milwaukee, Wise., USA). All hydroxy acids and phenols were acetylated with an excess of acetic acid and a catalytic amount of pyridine in refluxing toluene. All silylations were conducted with chloro-trimethylsilane and triethylamine in refluxing toluene or dioxane. 

Silylated alkyl phenols, alkyl phenyl ethoxylate Phenols, aromatic acids, eg pentachlorophenol, bisphenol, phthalic acid, trimesic acid, p-hydroxy-benzoic acid, vanilic acid, syringic acid, p-coumaric acid, ferulic acid... 

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