Resins efficiencies

Combination of amines and dendrimers functionalized proton scavenger resins efficiently removes excess reagents from amide-formation reactions. Marsh et al.41 used a supported branched polyamine and... 

Chemical and Related Savings. Improvement in resin efficiency when the finish is applied at low wet pick-up can be expected due to the reduction or elimination of migration during drying. 

If the reactants are applied uniformly, the absence of migration allows a lower average level of treatment to assure a given level of performance in the finished fabric. Experimental evidence for such an improved efficiency has been reported by several investigators (4, 13, 14). Results in our laboratories have confirmed a higher resin efficiency for polyester-cotton blend fabrics treated at low wet pick-up by controlled applica-... 

The amino acids at pH < p Kj are in their cationic form and can be retained on a cationic exchange resin (Ambertile IRC 120). The percolation of the water sample (pH =2) is conducted at a rate of 2 m h V the amino acids being then eluted by NH OH (1 N). After evaporation to dryness of the eluat, the residue is dissolved in a sodium borate buffer (H BOg 0.4 M, adjusted to pH = 9.5 with NaOH). The concentration factor is between 200 and the resin efficiency is 90-100%. 

Five years later Hatch and Dillon rediscovered the fact that conventional ion-exchange resins efficiently separate acids from their salts under conditions that exclude normal ion exchange. The strong basic anion-exchange resin Dowex-lx8 (8% divinylbenzene (DVB), 40% water content) was found to function especially well and the investigators decided to introduce acid retardation as a new term. Such separations can be defined as acid retardation separations, since they are based on a preferential absorption of strong acids, which causes the movement of the acid on the bed to be retarded — i.e., slowed down — relative to the movement of the salt [115]. Acid retardation, like ion retardation, can be done at high flow rates, especially at elevated temperatures. These processes have been optimized and since 1976 widely exploited by Eco-Tec Canada [119, 120], as well as by others [121], on the industrial scale. 

Rio Tlnto has also looked at how very fine lamellar talcs allow thtn-waH blow-molded HDPE bottles and packaging. Here, extra fine 1- to 2-itm Luzenac talc reportedly stiffens and strengthens the resin efficiently without excessively reducing... 

Low scrap Given that 80% of a film s cost may be tied to resin costs, a successful operation must use resin efficiently, minimizing waste or off-spec materials. 

The main reason to preserve the structure of the monolith on different scales is to make the transfer of chromatographic methods very simple and straightforward. Keeping a constant structure, the resin efficiency, normally measured in terms of height equivalent of theoretical plate (HETP), is also kept constant. Therefore, method transfer time can be significantly shortened since fewer experiments are required. 

Various components have been proposed to increase hardness, solvent resistance, and adhesion to substrates of PEDOTiPSS films. Cross-linking agents that can be cured by UV light increase hardness and wear resistance. Water-soluble melamine resins can be used to efficiently increase solvent resistance. Melamine resins efficiently cross-link acid catalyzed when heated. It is therefore presumed that for melamine the polystyrene sulfonic acid in PEDOTiPSS acts as a cross-linking catalyst. 

Place a mixture of 53 g. of A.R. lactic acid (85-88 per cent, acid), 75 g. (85-5 ml.) of commercial anhydrous isopropyl alcohol, 300 ml. of benzene and 20 g. of Zeo-Karb 225/H (1) in a 700 ml. bolt-head flask, equipped with an automatic water separator (e.g., a large modified Dean and Stark apparatus with a stopcock at the lower end, see Fig. Ill, 126, 1) carrying an efficient reflux condenser at its upper end, and a mercury-sealed stirrer (alternatively, the hquid-sealed stirrer shown in Fig. 11,7,11, c. may be used). Reflux the mixture, with stirring, on a steam bath for 5 hours or until water no longer collects in appreciable amount in the water separator run off the water from time to time. Filter off the resin at the pump and wash it with two 25 ml. portions of benzene. Shake the combined filtrate and washings with about 5 g. of precipit-ated calcium... 

During the late 1970s, concerns were raised about levels of airborne formaldehyde in buildings resulting primarily from constmction using composite panels bonded with urea—formaldehyde resins and combined with energy-efficient building practices which reduced air losses. 

As a 1.7 dtex (1.5 den) fiber, it can be spun into yams with a better strength conversion factor than other ceUulosics, aUowing rotor-spun Tencel to outperform ring-spun cotton or modal viscose. Fabrics can be made at high efficiency, and prove to have the anticipated tear and tensUe advantages over other ceUulosics. Direct, reactive, or vat dyes can be used, and easy care properties can be achieved with less resin finish than normal. Tencel could therefore be positioned as a new premium quaUty apparel ceUulosic and not simply as a long-term replacement for viscose. 

Tetrachlorphthalic Anhydride and Tetrachlorphthalic Acid. Tetrachlorphthalic anhydride [117-08-8] (TCPA) is manufactured by the ferric chloride catalyzed chlorination of phthalic anhydride. The relatively low chlorine content and the lower flame retardant efficiency of the aromatic chlorides limit use to unsaturated polyester resin formulations that do not requite a high degree of flame retardancy. 

Another type of soHd supetacid is based on perfluorinated resin sulfonic acid such as the acid form of Du Font s Nafion resin, a copolymer of a perfluorinated epoxide and vinylsulfonic acid or soHd, high molecular weight petfluotoalkanesulfonic acids such as petfluotodecanesulfonic acid, CF2(CF2)qS02H. Such sohd catalysts have been found efficient in many alkylations of aromatic hydrocarbons (225) and other Friedel-Crafts reactions (226). 

Economics. As with the alkyl tin stabilizers, the market pricing of the mixed metal stabilizers tend to be directed by the particular appHcation. The calcium—zinc and barium—cadmium packages are typically used at 2.0—4.0 parts per hundred of PVC resin (phr) in the formulation. These completely formulated products are sold for 2.50— 4.40/kg for the Hquid products and 3.20— 6.50/kg for the soHds and pastes. The higher efficiency products aimed at rigid appHcations tend toward the higher end of the cost range. 

Characterization. In many cases, ftir is a timely and cost-effective method to identify and quantify certain functionaHties in a resin molecule. Based on developed correlations, ftir is routinely used as an efficient method for the analysis of resin aromaticity, olefinic content, and other key functional properties. Near infrared spectroscopy is also quickly becoming a useful tool for on-line process and property control. 

G-5 Aliphatic Petroleum Resins. Carbocationic polymerization of C-5 feedstreams has been accomptished with various Friedel-Crafts catalyst systems. Table 3 compares the efficiencies of selected Lewis acids ia the polymerization of a typical C-5 stream containing 43 wt % C-5—C-6 diolefias and 47 wt % C-5—C-6 olefins (20). Based on weight percent yield of resia at equimolar coaceatratioas of catalyst (5.62 mmol/100 g), efficieacy follows AICI3 AlBr3 > BF3etherate-H20 > TiCfy > SnCl. The most commonly used catalyst in petroleum resin synthesis is AlCl. ... 

AlCl efficiency (based on g resin/g catalyst) can be markedly improved by polymerizing dry feeds (<10 ppm H2O) with an AlCl /anhydrous HCl system. Proceeding from 250 ppm H2O down to 10 ppm H2O, catalyst efficiency improves from 30.6 to 83.0 (26). Low levels of tertiary hydrocarbyl chlorides have been shown to gready enhance the activity of AlCl, while yielding resins with narrow molecular weight distributions relative to systems employing water or HCl (27). 

Aromatic diacyl peroxides such as dibenzoyl peroxide (BPO) [94-36-0] may be used with promoters to lower the usehil decomposition temperatures of the peroxides, although usually with some sacrifice to radical generation efficiency. The most widely used promoter is dimethylaniline (DMA). The BPO—DMA combination is used for hardening (curing) of unsaturated polyester resin compositions, eg, body putty in auto repair kits. Here, the aromatic amine promoter attacks the BPO to initially form W-benzoyloxydimethylanilinium benzoate (ion pair) which subsequentiy decomposes at room temperature to form a benzoate ion, a dimethylaniline radical cation, and a benzoyloxy radical that, in turn, initiates the curing reaction (33) ... 

Peioxydicaibonates are efficient polymerization initiators for most vinyl monomer polymerizations, especially for monomers such as acrylates, ethylene, and vinyl chloride. They are particularly good initiators for less reactive monomers such as those containing aHyl groups. They are also effective for curing of unsaturated polyester mol ding resins. 

Other hydrometaHurgical uses for resin have been smaH in comparison. Replacement of carbon as an adsorbent for gold [7440-57-5] from a cyanide [57-12-5] leached ore has been studied for many years, but remains in limited commercial use. A deterrent has been the failure to develop an efficient and... 

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