Polysiloxane copolymers

A blend of a polyoxyalkylene-polysiloxane copolymer and an alkoxy-lated phenol-aldehyde resin is useful as a demulsifier [1457, 1458]. 

The polyoxyalkylene units in the copolymer have a molecular weight below 500, and the polysiloxane units have 3 to 50 silicon atoms. The resin has a phenol/aldehyde ratio of 2 1 to 1 5 and an average molecular weight of 500 to 20,000 Dalton. The composition shows synergistic demulsification activity when compared with the individual components. The siloxane units can be either in blocks [979,980] of the polyoxyalkylene-polysiloxane copolymer or randomly distributed [728,729]. 

Venton, D.L., Cheesman, K.L., Chatterton, R.T. Jr., and Anderson, T.L. (1984) Entrapment of a highly specific antiprogesterone antiserum using polysiloxane copolymers. Biochimica et BiophysicaActa, 797,343— 347,... 

D. Kato, M. Kunitake, M. Nishizawa, T. Matsue, and F. Mizutani, Amperometric nitric oxide microsensor using two-dimensional cross-linked Langmuir-Blodgett films of polysiloxane copolymer. Sens. Actuator B-Chem. 108, 384—388 (2005). 

J.F. Hoover, J.-P. Lens, and B. Mullen, Polycarbonate-polysiloxane copolymers, method of making, and articles formed therefrom, US Patent 7 524 919, assigned to SABIC Innovative Plastics IP B.V. (Bergen op Zoom, NL), April 28, 2009. 

The formation of cellular products also requires surfactants to facilitate the formation of small bubbles necessary for a fine cel] structure. The most effective surfactants are polyoxyalkylene-polysiloxane copolymers. The physical properties of polyurethanes are derived from their molecular structure and determined by the choice of building blocks as well as the suprainolecular structures caused by atomic interaction between chains. The ability to crystallize, the flexibility of the chains, and spacing of polar groups are of considerable importance, especially in linear thermoplastic materials. In rigid cross-linked systems, e.g., polyurethane foains, other factors such as density determine the final properties. 

Some authors combined the IPN concept with the use of compatibi-lizers similar to that mentioned in Section 2. These may be a coupling agent such as epoxy-functionalized polysiloxane, polysiloxane copolymers or an organofunctional grafted polyolefin such as poly(ethylene-co-methacrylate) or MA-g-EPDM (maleic anhydride grafted EPDM) [124,125, 133]. Knaub et al. [150] studied a poly(urethane-ureas)/PDMS semi-IPN in... 

An original approach for combining polysiloxanes and sugars has been reported by Thiem et al. [32] and Domschke et al. [33], with the preparation of main-chain carbohydrate-polysiloxane copolymers. In these structures, the sugar units are... 

By relying and combining classical and innovative polymerization concepts, polysiloxane copolymers with different degrees of phase segregation morphologies can be prepared from the raw materials. Sanqiles of standard and customized copolymers are available on request. 

Mechanistic considerations (e.g., the extensive work published on brush-type phases) or the practitioner s experience might help to select a chiral stationary phase (CSP) for initial work. Scouting for the best CSP/mobile phase combination can be automated by using automated solvent and column switching. More than 100 different CSPs have been reported in the literature to date. Stationary phases for chiral pSFC have been prepared from the chiral pool by modifying small molecules, like amino acids or alkaloids, by the deriva-tization of polymers such as carbohydrates, or by bonding of macrocycles. Also, synthetic selectors such as the brush-type ( Pirkle ) phases, helical poly(meth) acrylates, polysiloxanes and polysiloxane copolymers, and chiral selectors physically coated onto graphite surfaces have been used as stationary phases. 

The pyrolysate of polyacrylic-/nfer-nef-polysiloxane copolymer contains as main fragment molecules pyrolysis products similar to those of poly(butyl acrylate) and of poly(dimethylsiloxane (see Figure 6.7.8. and Section 16.1). The identification of fragments that would indicate sequences of other comonomers or any molecular connections between the two types of comonomer units was not possible. Other copolymers with acrylic acid as comonomer were studied using analytical pyrolysis. Among these are copolymers with special properties such as the copolymer with the formula shown below ... 

Other Py-GC and Py-GC/MS studies on polysiloxane copolymers are reported in literature [21, 22], etc. In one such study [21] several polysiloxanes used as liquid crystals, which contain benzyl ether and biphenyl ether side chain groups, were analyzed by Py-GC/MS. The general formula for these compounds is shown below ... 

Figure 9.6 Frequent-use conditioning shampoo formulation (a cocamidopropyl betaine, ex Henkel Chemicals, Dusseldorf, Germany b hydrolysed wheat protein polysiloxane copolymer, ex Croda Chems, Goole, UK c glycol distearate and laureth-4 and cocamidopropyl betaine, ex Henkel)...

Figure 6.47. A cholesteric polysiloxane copolymer applied in the optical information storage application.

The characterization of polysiloxane copolymers first requires the determination of the molecular weight distribution (MWD) and the related average molecular weights and the number average degree of polymerization (DP). These measurements are then followed by the analysis of functional groups with regard to their nature, their concentration and their relative positions in the macromolecular chain. 

Crodasone. [Croda Inc.] Hydrolyzed wheat protein polysiloxane copolymer film-forming and substandvity agent, lubricant, condidoner for skin and hair care prods. 

Structurally Well-Defined Amphiphilic Polysiloxane Copolymers... 

Ou et al. [179] reported on the successful fabrication of X-deposited multilayer films using the Langmuir-Schaefer deposition technique [187]. They used a polysiloxane copolymer containing both a mesogenic and an NLO side chain (30). 

Chem. Descrip. Polysiloxane copolymer emulsion in water Uses Defoamer for aq. systems, architectural coatings, building prods., industrial and wood coatings, printing inks, adhesives, emulsions Features Exc. stability resist, to acid and alkaline environment suitable for use at pH 2-11... 

Chem. Descrip. Polysiloxane copolymer and hydrophobic silica aq. emulsion... 

Chem. Descrip. Sol n. of a mixlified polysiloxane copolymer in 2-butoxy-ethanol/2-ethyl-l-hexanol/Stod. 2IM)... 

Chem. Descrip. Polyether modified dimethyl polysiloxane copolymer in xylene... 

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