Tests for Physical Properties

Tensile strength refers to the maximum stress the film can sustain before it actually fractures quite literally, the amount of force necessary to pull a material apart. The SI unit of tensile strength is the pascal (English units are pounds per inch of original cross-sectional area). Elongation refers to the amount the material will stretch before breaking. 

The following material properties can be calculated from the tensile strength test (at yield and at break) tensile strength, tensile modulus, strain, elongation and percent elongation at yield, and elongation and percent elongation at break. (See Fig. 1.) 

For a specimen sample, ASTM D882 uses strips cut from thin sheet or film ASTM D638 requires a Type I standard dumbbell-shaped tensile bar. 

Impact Resistance of Plastic Film by the Free-Falling Dart Method. Primary Film Test Method ASTM D1709 Additional Test Method ISO 7765-1. A weighted dart is dropped from a standard height onto a taut sample. Depending upon the expected impact strength of the test sample, either method A or method B is chosen. The method defines the dart size and the drop height for the dart. Test method A specifies a dart with a 38 mm diameter dropped from 0.66 m. Test method B specifies a dart with a 51 mm diameter dropped from 1.5 m. 

The dart unit is the weight of dart in grams that breaks the sample fifty percent of the time, also called failure weight. These tests give an index of the material s dynamic strength and predict resistance of a material to breakage from dropping or other quick blows. 

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There are tests for physical properties such as deasity and hardness (qv) of plastics. Microscopy (qv) is important ia fracture analysis as well as ia analysis of the morphology of polymer systems for an understanding of polymer blend performance. 

BS 4965 for composite boards and panels includes very few tests for physical properties but specifies precisely the individual components for each type of composite construction, referring to the appropriate standards. 

BS 6463, Part 4 Methods of test for physical properties of hydrated lime and lime putty , 1987. 

More than 100 000 individual liquid crystals have been prepared until now [1.1-4]. About 2000 of them have been tested for physical properties and technical applications [1.5-14]. These materials can be classified... 

Elastomer samples are cast in molds, the size and shape of which depend on its purpose. Samples for physical properties can be produced using a custom-made book mold designed to create a thin sheet (0.1 in.) containing premolded test parts, such as those for die-C tear, flexural modulus, and so on. Alternatively, a flat plaque mold may be used to create a 6 x 6 x 0.1-in. sheet from which may be cut samples for testing. Thicker samples for hardness measurements may... 

The cured polymer samples used for physical property testing were prepared by photocuring 12 mil thick sheets of degassed and photosensitized monomer mixtures, using a mold composed of glass plates lined with polyester film and separated by a double thickness of vinyl electrical tape. A GE sunlamp was used for Illumination, and Darocure 1173 (E. Merck) was used as the photoinitiator. Hydrocarbon monomers were used as received from the manufacturers. All the vinyl group-containing compounds were stored at -5°C until use. 

Ormos, Z., Studies on granulation in fluidized bed, 1. Methods for testing the physical properties of granulates, Hungarian. Ind. Chem., 1 (1973) 207-228. Ormos, Z., Pataki, K. and Csukas, B., Studies on granulation in fluidized bed,... 

Distinction should be made at this time between diastereoisomers and enantiomers. The former are characterized by the presence of at least two closely associated asymmetric centers in the molecular structure, either of which can epimerize. Altogether then there are two pairs of enantiomers for a total of four stereochemically unique individuals. Diastereoisomers have different physical properties and as a result discriminations, and even separations, can be done relatively easily. Enantiomers on the other hand differ in only one physical property, i.e. the direction of rotation of polarized light. Reaction of an enantiomeric racemic mixture with a third chiral species will produce a mixture of diastereomers therefore facilitating their identification or their separation. Early examples of this were the separations done by fractional crystallization of salts produced by a derivatization reaction with, for example, the alkaloid (-)-brucine. Fractional crystallization would never seem to be an effective analytical method yet it was used with some success in a forensic sciences context to confirm the presence of (L)-cocaine by a carefully contrived microcrystalline test. The physical properties... 

C. Alginate "Snakes" This makes an excellent demonstration on an overhead projector. Fill a crystallizing dish or beaker to a depth of Vi to 3A inch with 2% Ca(N03)2 solution. Introduce a stream of 2% sodium alginate solution directly into the- Ca2+ solution using a pipet. You should be able to cause the formation of a long strand of gel (a snake ). For the most part, the properties of the strands should be the same as those of the beads that you explored above. To test the physical properties of your snakes, wash them in fresh water and let them dry. As they are drying, periodically test their strength and note their appearance. 

Mocks are nonexplosive simulants for high explosives. They duplicate the properties for test purposes without hazard. The required properties to copy need different mocks, e.g., for physical properties, for density, or for thermal behavior. 

Table 22.1. ASTM and ISO Designations for Physical Properties Tests...

The remote setting of the Earth s core tests our ability to assess its physical and chemical characteristics. Extending out to half an Earth radii, the metallic core constitutes a sixth of the planet s volume and a third of its mass (see Table 1 for physical properties of the Earth s core). The boundary between the sihcate mantle and the core (CMB) is remarkable in that it is a zone of greatest contrast in Earth properties. The density increase across this boundary represents a greater contrast than across the crust-ocean surface. The Earth s gravitational acceleration reaches a maximum (10.7 m s ) at the CMB and this boundary is also the site of the greatest temperature gradient in the Earth. (The temperature at the base of the mantle (—2,900 °C) is not well established, and that at... 

Off-line monitoring using traditional tests for physical and chemical properties as well as less or non-traditional testing such as NIR, To repeat an earlier comment. 

The OECD Guidelines for the Testing of Chemicals is a collection of standard methods used by professionals in governments, industry, academic institutions, and independent laboratories for safety testing of chemical substances. They cover tests for physical-chemical properties, effects on biotic systems (ecotoxicity), environmental fate (degradation/ accumulation), and health effects (toxicity) (see Table 1). The Test Guidelines are systematically updated to respond to scientific progress or to address new needs identified by member countries. They are published in two loose-leaf binders, and are also available in a CD-ROM version. 

Crutcher, D., Gervais, R. and Toms, L., Use of FT-IR Spectrometry as a Replacement for Physical Property Testing of Railway Lubricants , Proceedings of the Technology Showcase-Integrated Monitoring, Diagnostics and Failure Prevention Conference, Ed. G. Humphrey, Mobile, AL, pp. 207-216, 1996. 

Test for Plastic Properties of Coal by the Gieseler Plastometer Test for Expansion or Contraction of Coal by the Sole Heated Oven Test for Plastic Properties of Coal by the Constant Torque Gieseler Plastomer Definition of Terms Relating to Lithologic Classes and Physical Components of Coal Preparing Coal Samples for Microscopical Analysis by Reflected Light Microscopical Determination of the Reflectance of the Organic Components in a Polished Specimen of Coal... 

The authors would like to thank and acknowledge the efforts and support of the following people at Air Products and Chemicals, Inc. Mark A Eckert, Steven E Robbins for physical property testing of foams generated in this study, and Ilean S Ruhe for preparation and editing of this work. We would also like to thank Air Products and Chemicals, Inc., for support of this work and permission to publish it. 

Federal Test Method Standard No. 175B for physical properties Methods 4032.1,4041.1, and 4051.1. 

Mechanical Machining Methods. The inherent pliability and shear properties of plastics, particularly of thermoplastics, makes them highly amenable to shaping with traditional tools such as saws, drills, planes, shapers, lathes, sanders, and millers. The materials are easily cut by steel tools, which are harder than any plastic. For this reason, mock-up designs are often initially constructed as plastic models rather than as metal constructs, allowing design engineers to test various physical properties, such as aerodynamic stability and wind resistance, that are directly related only to the shape of the structure and not to the materials used. 

Chemical analysis of polymers typically deals with monomers or functional groups rather than constituent atoms. Thermal infrared and laser optical Raman spectrometry are the typical tools (36) (see Test Methods Vibrational Spectroscopy), but frequently, specific specimen size or form is required. For physical properties, mechanical and sonic/ultrasonic NDT methods are available (see above). Molecular mass distribution and related properties of polymers, or fiber or particle volume fraction and distribution for PMC, are usually determined destructively (see Test Methods). 

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