Resins 276 INDEX

Surface Coating Resin Index, The British Plastics Federation, England. 

E. Karsten, O. Liickert Lackrokstoff-Tabellen. Curt R. Vincentz Verlag, Hannover 1987. Resin Index, British Resin Manufacturer s Association, Redhill, Surrey 1986. 

E. Rarsten, O. Luckert Lackrohstoff-Tabellen, 9th edition, C. R. Vincentz Verlag, Hannover (1992), pp. 522-549 Resin Index of the British Resin Manufacturers Association Raw Materials Index - Resins , National Paint and Coatings Association, USA. 

Selar Packaging, DuPont.com. (http // WWW. dupont. com/packaging/products/resins/ index. htmlHselar)... 

Canada Balsam Resin, index of refraction n = 1.537, and Lakeside 70 (a synthetic resin, n = 1.54) available from most chemical and petrographic supply houses. 

Testing. Melt index or melt flow rate at 190°C, according to ASTM D1238, is the test most frequently appHed to the characterization of commercial acetal resins. The materials are typically grouped or differentiated according to their melt flow rate. Several other ASTM tests are commonly used for the characterization and specification of acetal resins. 

Many grades of acetal resins are Hsted in Underwriters Eaboratories (UL) Kecogni d Component Directory. UL assigns temperature index ratings indicating expected continuous-use retention of mechanical and electrical properties. UL also classifies materials on the basis of flammability characteristics homopolymer and copolymer are both classified 94HB. 

Ionomer resins are produced in multiple grades to meet market needs, and prospective customers are provided with information on key processing parameters such as melt-flow index. Nominal values for many other properties are Hsted in product brochures. The ASTM test methods developed for general-purpose thermoplastic resins are appHcable to ionomers. No special methods have been introduced specifically for the ionomers. 

A wide variety of chromium oxide and Ziegler catalysts was developed for this process (61,62). Chromium-based catalysts produce HDPE with a relatively broad MWD other catalysts provide HDPE resins with low molecular weights (high melt indexes) and resins with a narrower MWD (63,64). 

Molecular Weight. The range of molecular weights of commercial LLDPE resias is relatively narrow, usually from 50,000 to 200,000. One accepted parameter that relates to the resin molecular weight is the melt index, a rheological parameter which, broadly defined, is inversely proportional to molecular weight. A typical melt index range for LLDPE resias is from 0.1 to 5.0, but can reach over 30 for some appHcations. 

The molecular weight distribution of LLDPE resins is usually characterized in industry by the ratios of melt indexes measured in the same apparatus using different loads (2.16, 10.16, and 21.6 kg). The commonly used ratios are melt flow ratio, MFR) and I q/I2. Both of these ratios... 

Fig. 9. Melt flow index as a function of temperature for varying molecular weights of poly(ethylene oxide). WSR = Polyox water-soluble resins.

The first appearance of the term "alkyd resin" in the subject index of Chemicaly bstracts 2iS. in 1929, under Resins. It was not until 1936 that Alkyd Resins was Hsted in its alphabetical place, but stiU appeared as "See Resinous Products." The proliferation of Hterature on alkyd resins peaked from the 1940s through the 1960s. Research activities on alkyds in the United States, as indicated by the number of pubHcations, has apparentiy tapered off since the 1970s. Readers interested in alkyd history can find more detailed historical reviews elsewhere (1 4). 

The natural resins described here are those that have been mentioned in technical Hterature they can be identified by CAS Registry Numbers and Merck Index numbers (1). 

Various polymers, such as polythiourethanes, polythioethers, and polythioacrylates, are used to produce resins which are transparent, colorless and have a high refractive index and good mechanical properties, useful for the production of optical lenses. Higher refractive indices are promoted by sulfur compounds and especially by esters of mercaptocarboxyhc acids and polyols such as pentaerythritol (41) (see Polymers containing sulfur). 

Many attempts have been made to characterize the stabiUty of the colloidal state of asphalt at ordinary temperature on the basis of chemical analysis in generic groups. For example, a colloidal instabiUty index has been defined as the ratio of the sum of the amounts in asphaltenes and flocculants (saturated oils) to the sum of the amounts in peptizers (resins) and solvents (aromatic oils) (66) ... 

Color/Transparency. Almost all amorphous engineering thermoplastics, except PC and some polyester carbonates, are inherently colored. Even polycarbonates have yellowness indexes (YI) (36) of 0.1 to 5.0. Colorless material is produced from these resins by compounding with complementary blue dyes which reduce transmission. Ha2e in amorphous resins is an indication of particulates. Ha2e reduces optical clarity and transmission. 

Most PET botties are produced by injection blow mol ding (71) the resin over a steel-core rod. The neck of the bottie is formed with the proper shape to receive closures and resin is provided around the temperature-conditioned rod for the blowing step. The rod with the resin is indexed to the mold, and the resin is blown away from the rod against the mold walls, where it cools to form the transparent bottie. The finished bottie is ejected and the rod is moved again to the injection-molding station. This process is favored for single cylindrical botties, but cannot be used for more complex shapes such as botties with handles. 

Ethyl Vinyl Ether. The addition of ethanol to acetylene gives ethyl vinyl ether [104-92-2] (351—355). The vapor-phase reaction is generally mn at 1.38—2.07 MPa (13.6—20.4 atm) and temperatures of 160—180°C with alkaline catalysts such as potassium hydroxide and potassium ethoxide. High molecular weight polymers of ethyl vinyl ether are used for pressure-sensitive adhesives, viscosity-index improvers, coatings and films lower molecular weight polymers are plasticizers and resin modifiers. 

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