Polymer spot test

Spot tests, 245 Spray elastomers, 204 Star-branched polymers, 187 Star copolymers, 7... 

A chromotrophic acid spot test for formaldehyde (23) was also negative for the polymer ozonolysis solution, while it was positive for a control solution containing formaldehyde equivalent to that expected in the experimental solution if one per cent of the double bonds were vinyl, i.e., polymerization via the internal double bond. 

For identification of ceiiuiose acetates or propionates, one can use the reaction with ianthanum nitrate. In this test, one adds one or two drops of a 50% aqueous ianthanum nitrate solution and one drop of a 0.1 N iodine solution to a small amount of the polymer sample on a spot test plate. Then a drop of concentrated ammonia is added. If cellulose acetates are present, one quickly observes a blue coloration with cellulose propionate the coloration is brown. 

Chapter 5 discusses the reasons and techniques for identifying plastics in collections. In addition to establishing the age and technological history of a plastic, identification indicates the factors and pathways by which degradation is likely to occur and thus helps the conservator to develop a treatment strategy. Simple tests enable identification of the polymer type while instrumental techniques are necessary if the various components are to be characterized. This chapter describes simple and non-destructive tests, simple and destructive tests, chemical spot tests and instrumental analytical techniques which are applied to plastics in collections today. 

Spot tests for identifying polymers or their components... 

Spot test of the cleanliness of sensitive surfaces such as glass or silicon wafers for microelectronics fabrications. Both surfaces are high energy (see text below) and are completely wetted by pure water. If the surface is contaminated by something such as an oil that interferes with the processing of the material (e.g., the coating of a photoresist polymer), a drop of water will have a nonzero contact angle, and the contamination will be immediately apparent. 

Like phenol resins, epoxy resins can be identified rapidly with the help of a number of relatively simple, yet reliable chemical spot tests, but they serve mostiy only for establishing the class of polymer. More subtle analytical techniques are required to characteri.se technical epoxy resin formulation, especially in the presence of additives, fillers or perhaps even of spurious materials. The decisive breakthrough in the systematic characterisation of epoxy resins came with the introduction of thermal degradation procedures into polymer analysis. The polymer composition can be established beyond doubt from the separated and identified products of thermal degradation. The problems of separation and detection of these products have been solved to practice by GLC - and... 

The first pilot test in Daqing was started on August 30, 1972, and ended on September 24 in the same year, a total of 26 days. This test was conducted in the Sall7+8 layer. One inverted four-spot pattern was used with the injector, Well 501, in the center. Thus, it was called the Well 501 pattern. The distance between the injector and a producer was 75 m. The formation thickness was 5.2 m, and the permeability was 631 md. The reservoir temperature was 45°C. A 0.163 PV of polymer solution was injected having a concentration from 1000 to 1800 mg/L. The three producers started to respond after 12 days of polymer injection. The water cut at one producer (Well 503) was reduced from 99 to 60.4%, and the well pattern incremental oil recovery was about 5%. The well injection pressure increased, and the liquid production rate was reduced significantly. In this first pilot test, low molecular weight polymer (3 to 5 million Daltons) was used (Liu, 1995 Yang et al., 1996). 

Bei-l-Qu-Duan-Xi was the first large-scale polymer flooding field application in the northern Saertu field, Daqing. There were 25 injectors and 37 producers in the test area in five-spot patterns. The target layers were PI1.4. The well spacing from injector to producer was 250 to 300 m. Some of the reservoir and flnid data are shown in Table 5.22 (Chang et al., 2006 Yan et al., 2006). 

Most of polymer floods in Daqing were conducted in oil zones. There are a significant amount of reserves in transition zones. In 1995, the Sabei transition zone was selected for a polymer flooding pilot test. The target formation was PI1.4. The basic reservoir, fluid, and well data are shown in Table 5.24 (Niu et al., 2006). The well pattern was irregular four-spot. 

Spot/, G.. Recent Developments in Meat Aging Tests and Equipment. Polymer Testing. /.5.. 481 (1996),... 

To be of any praetieal use, an object made from a polymeric material must be able to retain its shape when subjected to even small tensions or compressions over long pmods of time. This dimensional stabiUty is an important consideration in choosing a polymer for use in the manufacture of an item. No one wants a plastic telephone reedver that sags after sitting in its cradle for several weeks, or a car tire that develops a flat spot if parked in one position for too long, or clothes made from synthetic fibers that become baggy and deformed after short periods of wear. Creep tests provide a measure of this tendency to deform and are relatively easy to carry out. 

Knall et al. have tested a series of europium complexes with antenna chromo-phores in different polymer matrices in terms of sensitivity, response time, and dynamic range for the sensing of water vapor. A copolymer containing a Eu " chelate that can be spin-cast as thin film on glass slides was developed [110]. Scheme 6 shows the chemical structure of the polymerizable precursor 29. This complex can be copolymerized with norbomene-2,3-dicarboxylic acid dimethyl ester by means of ring opening metathesis polymerization. The sensor spots respond to water vapor by reversible luminescence quenching, which can be analyzed by means of phase sensitive measurements of luminescence lifetime [110]. 

Phosphoric acid has traditionally been used as a conditioner of enamel and dentin for adhesive restorative treatments, as desalbed in section Polymers in Dental Adhesion . 37 % phosphoric acid has been shown to decalcify enamel and dentin in a desirable pattern, thus facilitating impregnation of adhesive monomers required for placement of composite resin restorations in the tissue matrix. Despite the known efficiency of 37 % phosphoric add gels in acid-etching enamel and dentin, it has been shown that its effects in increasing the surface porosity of the pseudo-intact surface layer of enamel lesions was not sufficient [117]. To overcome this limitation, 15 % hydrochloric acid (generally for 2 min) has been tested and shown to remove about 30 pm of surface enamel, thus allowing for much improved penetration of viscous resins in white spot lesions [116]. 

A xanthan biopolymer (C= 1,500 ppm) is to be used for mobility control in a waterflood in a sandstone reservoir. Flow characteristics of the biopolymer are given by the correlations developed by Willhite and Uhl in Eqs. 5.23e through 5.23g Table 5.66 gives properties of the reservoir. An injectivity test is planned in a watered-out five-spot pattern with a pattern area of 5 acres. Predict the pressure drop between the injection well and the effective radius of the pattern as a function of volume of polymer injected when 5,000 bbl of polymer is injected at a constant rate of 10 B/D-ft. Plot pressure drop as a function of volume of polymer injected (barrels). Assume that the region around the wellbore is at ROS and the permeability to water at ROS is 50 md. The polymer is shear thinning until the Darcy velocity is less than 0.1 ft/D. Polymer retention is 40 Ibm/ acre-ft. The density of the water is 62.4 Ibm/ft at reservoir temperature. Find the fraction of polymer retained. Determine the time required for the injectivity test. 

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