Polymers high molecular weight commercial

Polymerization-structure-properties. BCMO is polymerized by the cationic way in different inert solvents. Alkylaluminum compounds yield polymers of high molecular weight. Commercial polymers may reach molecular weights of 250,000-300,000. 

Formaldehyde f6r- mal-d9- hld, fer- [ISV form- + aldehyde] (1872) (formic aldehyde, methanal, oxymethylene) n. HCHO. A colorless gas with a pungent, suffocating odor, obtained most commonly by the oxidation of methanol or low-boiling petroleum gases such as methane, ethane, etc. The gas is difficult to handle, so it is sold commercially in the form of aqueous solutions (formalin), solvent solutions, as its oligomer, paraformaldehyde, and as the cyclic trimer, 1,3,5-trioxane (a-trioxym-ethyl-ene). High-molecular-weight, commercial polymers of formaldehyde are called poly-oxymethylene or acetal resin. Formaldehyde is also used in the production of other resins such as phenolic resin (phenol-formaldehyde) and amino resin (urea formaldehyde). Syn methylene oxide, methanal. See formalin. 

Polystyrene [9003-53-6] (PS), the parent of the styrene plastics family, is a high molecular weight linear polymer which, for commercial uses, consists of - 1000 styrene units. Its chemical formula (1), where n = - 1000, tells htde of its properties. 

The reaction with aromatic diamines is catalyzed by carboxylic acid and leads to high molecular weight linear polymers [43]. By controlling the molar ratio of the reactants this reaction has been used to produce low molecular weight pol-yaspartimides end-capped with maleimide (Fig. 11). Such types of oligomers called Kerimid were formerly commercialized by Rhone-Poulenc. 

Carbomers are synthetic, high-molecular-weight, crosslinked polymers of acrylic acid. These poly(acrylic acid) polymers are crosslinked with allyl sucrose or allyl pentaerythritol. The polymerization solvent used most commonly was benzene however, some of the newer commercially available grades of carbomer are manufactured using either ethyl acetate or a cyclohexane-ethyl acetate cosolvent mixture. The Carbopol ETD resins are produced in the cosolvent mixture with a proprietary polymerization aid, and these resins are crosslinked with a polyalkenyl polyether. 

Substituted poly(organosilanes) [-SiRR -] have recently become the focus of intense scientific and commercial interest, and synthetic efforts have been successful in obtaining high molecular weight organosilane polymers and copolymers containing both alkyl and aryl substituents. 

Carbomer. Cross-linked poly (acrylic acid) (Fig. 6.5) of high molecular weight, commercially available as Carbopol (B.F. Goodrich Chemical Company, Cleveland, Ohio), is widely used in ophthalmology to enhance precorneal retention to the eye. The superiority of Carbopol over simple saline and suspensions in enhancing precorneal residence time [36] and drug bioavailability [37, 38] has been demonstrated by several authors. Preparation of Carbopol hydrogels is simply based on the dispersion of the polymer in water at room temperature, followed by... 

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