Plastics preparation

PUR are a broad class of highly cross-linked plastics prepared by multiple additions of poly-functional hydroxyl or amino compounds. Typical reactants are polyisocyanates [toluene diisocyanate (TDI)] and polyhydroxyl molecules such as polyols, glycols, polyesters, and polyethers. The cyanate group can also combine with water this reaction is the basis for hardening of the one-part foam formulations. 

ISO 4612 1999 Plastics - Preparation of PVC pastes for test purposes method... 

ISO 11468 1997 Plastics - Preparation of PVC pastes for test purposes - Dissolver method ISO 12092 2000 Fittings, valves and other piping system components made of unplasticized poly(vinyl chloride) (PVC-U), chlorinated poly(vinyl chloride) (PVC-C), acrylonitrile-butadiene-styrene (ABS) and acrylonitrile-styrene-acrylester (ASA) for pipes underpressure - Resistance to internal pressure - Test method... 

ISO 9353 1991 Glass-reinforced plastics - Preparation of plates with unidirectional reinforcements by bag moulding... 

Under the heading acrylic elastomer the plastic literature has included a broad spectrum of carboxy-modified rubbers that have as a minor portion of the comonomers acrylic acid and/or its derivatives. However, in more recent usage the term acrylic elastomer is used to designate these rubbery products that contain a predominant amount of an acrylic ester, such as ethyl acrylate or butyl acrylate in the polymer chain. Fluoroacrylate elastomers are based on plastics prepared from the acrylic acid ester-dihydroperfluoro alcohols. 

The DHI s may be solution cast with certain polymers. Examples of photochromic plastics prepared this way are poly (methyl methacrylate), poly (n-butyl methacrylate), copoly (vinylidene chloride-acrylonitrile) (e.g., SARAN F), polycarbonate, and polystyrene-butadiene (e.g., Panarez). 

Use Electron tubes resistor cores windows in klystron tubes transistor mountings high-temperature reactor systems additive to glass, ceramics, and plastics preparation of beryllium compounds catalyst for organic reactions. 

Though useful polymers can be made by these reactions, their low ceiling temperatures (see p. 599) and consequent tendency to undergo facile depolymerization by an unzipping mechanism pose serious limitations. To overcome this problem the technique of end-capping or end-blocking may be used. Thus poly-oxymethylene (polyacetal), an engineering plastic, prepared from the cyclic acetal... 

The quality of life currently enjoyed by a large proportion of the world s population is ever more dependent upon the multitude of various materials we are able to produce and use. Fabrics, plastics, prepared and preserved foodstuffs and pharmaceuticals exemplify broad categories of products that are used everyday by millions. All these commodities are the result of manufacturing and conversion processes that are controlled for quality, consistency and economic viability. 

ISO 3167, Plastics--Preparation and use of multipurpose test specimens. International Organization for Standardization, 1993. 

ISO 2818-1994, Plastics—Preparation of test specimens by machining. International Organization for Standardization, 1980. 

BS2782, Method 930A-1996, Methods for testing plastics Preparation of test specimens by machining. British Standards Institute Publication, 1983. 

ISO 1268. Composites and reinforced plastics—Preparation of test plates. 

Chapter 3 describes the various components of plastics and how they are transformed into three-dimensional functional solids. The chapter is not intended as a technical manual from which polymers can be synthesized and plastics prepared but as an overview of selected procedures and materials relevant to museum professionals concerned with plastics. Knowledge of plastics technology helps to date plastics objects, to interpret chemical analysis of plastics and to understand the causes of deterioration. Polymerization, additives and shaping processes contribute to the physical and chemical properties, useful lifetime and degradation pathways of plastics. The optical, chemical and physical properties of plastics are detailed in Chapter 4. 

Thermoplastics pipes, fittings and assemblies for the conveyance of fluids -Determination of the resistance to internal pressure Part 1 General method Plastics - Preparation of test specimens by machining (Technical corrigendum - TC 1 2007)... 

SFS-EN ISO 4612 Plastics. Preparation of PVC pastes fortes purposes. Planetary-mixer method (ISO 4612 1999)... 

Fig. 4.26 Structure and synthesis of bisphenol A (BRA) and the most significant plastics prepared from it. (Authors own work)...

ISO Plastics—Preparation of glass fibre reinforced, resin bonded, low-pressure laminated... 

The patented Hammer s Plastic Recycling process from Iowa is not sold, but rather operated as a joint venture. The process accepts post-consumer plastics and industrial/commercial scrap disemds. A typical blended mixture of plastic prepared for final processing is 6.5% LDPE, 20% HOPE, 5% PP, 5% PET and 5% miscellaneous. The extrusion machine consists of a fill sensing device, heated extmsion nozzle, screen apparatus and an automatic sprue cutting device [Hammer, 1989]. Closed molds are filled under pressure ranging from 100 psi to 600 psi. Machine throughput is 800 - I,OCX) pounds/hour. 

Recycled plastic (reclaimed plastic) n. A plastic prepared from discarded articles that have been cleaned and ground (ISO). This material may or may not be reformulated by the addition of stabilizers, plasticizers, fillers, pigment, etc. 

Titanium dioxide, rutile n. Ti02- Pigment white 6 (77891). A high-opacity, bright white pigment, non-chalking type, used as a prime pigment in paints, rubber, plastics. Prepared from the mineral, ihnenite, or rutile ore. Density, 3.9-4.2g/cm (33-35 lb/ gal) O.A., 16 8 particle size, 0.2-0.3 pm, refractive index, 2.76. Syn titania. 

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