Thermal properties tests, plastics

Figure 5-6 and Tables 5-3 to 5-5 provide an introductory guide to the different thermal properties of plastics. Heat resistance properties of plastics retaining 50% of properties obtainable at room temperature with plastic exposure and testing at elevated temperatures are shown in Fig. 5-6 for the general family or group type. 

In order to select materials that will maintain acceptable mechanical characteristics and dimensional stability one must be aware of both the normal and extreme thermal operating environments to which a product will be subjected. TS plastics have specific thermal conditions when compared to TPs that have various factors to consider which influence the product s performance and processing capabilities. TPs properties and processes are influenced by their thermal characteristics such as melt temperature (Tm), glass-transition temperature (Tg), dimensional stability, thermal conductivity, specific heat, thermal diffusivity, heat capacity, coefficient of thermal expansion, and decomposition (Td) Table 1.2 also provides some of these data on different plastics. There is a maximum temperature or, to be more precise, a maximum time-to-temperature relationship for all materials preceding loss of performance or decomposition. Data presented for different plastics in Figure 1.5 show 50% retention of mechanical and physical properties obtainable at room temperature, with plastics exposure and testing at elevated temperatures. 

Gebauer et al. [38] suggest visbreaking of waste plastics with vacuum residue. This is a thermal process, applied in refineries in order to convert partially atmospheric vacuum residue and decrease viscosity and melting temperature. According to the authors, addition of 5% of waste plastics in laboratory tests does not influence noticeably the process parameters and final products properties. As in the case of LCO and VGO fractions the application of vacuum residue and mixture of waste plastics is applicable in refineries. 

In this chapter, we present results of the testing of a broad spectrum of polymers in carbon dioxide over a range of temperatures and pressures and evaluation of the effect of the high pressure carbon dioxide on the chemical/physical properties of materials tested. The testing was performed in a static manner with four controlled variables, namely temperature, pressure, treatment time and decompression time. The evaluation of the interaction of high pressure carbon dioxide with polymers included sorption and swelling behavior, solubility issue, plasticization and crystallization, and mechanical properties. The results of these evaluations are discussed in three sections Sorption, Swelling and Dissolution of Carbon Dioxide in Polymers at Elevated Pressure, Thermal Properties, and Mechanical Properties. ... 

ISO 10351 (1992). Method of testing plastics. Part I. Thermal properties, determination of the combustibility of specimens using a 125 mm flame source. 

Thermal properties n. All properties of materials involving heat or changes in temperature. In Section 08 of ASTM s Annual Book of Standards ( Plastics ), tests listed under Thermal Properties include many properties, from brittleness temperature, coefficient of expansion, deflection temperature, etc., to heat of fusion, glass-transition temperature, thermal conductivity, heat capacity, mold shrinkage, flammability, and many more. 

The objective of this research Is the examination of the effects of ion bombardment on the structure of thin ceramic films on ceramic substrates. The material combinations will Include oxide films that have (a) no solid solubility, (b) limited solid solubility, and (c) complete solid solubility with the substrate material (also an oxide). Techniques for determination of elastic and plastic properties of thin films or coatings on ceramic substrates and for the determination of the strength of the bond between the film and substrate, which are currently being developed, will be used to determine the hardness, elastic modulus, and adherence of each material combint tion. The main testing techniques will be the ultra-low load micro-indentation tester (Nanaindenter) and thermal cycling tests. 

Test Properties, Testing Frequency and Recommended Warrant for High Density Polyethylene (HDPE) Smooth and Textured Geomembranes Seam Strength and Related Properties of Thermally Bonded Polyolefin Geomembranes Certification Guidelines for Plastic Geomembranes Used to Line Landfills and Contaminated Sites... 

The primary consensus-based organizations in the United States developing and maintaining fire and flammability test standards are ASTM International (previously the American Society for Testing and Materials) and the National Fire Protection Association (NFPA). Committee EOS on Fire Tests is the primary committee in ASTM that develops fire and flammability test standards (25). Several material- or product-oriented Committees have subcommittees that develop fire and flammability test standards as well. For example. Committee D20 on Plastics has a subcommittee on thermal properties (D20.30) that develops and maintains some fire and flammability test standards for plastics. The Fire Test Committee is responsible for all fire and flammability test standards that are used by any of the fire safety codes and standards published by NFPA. A number of test laboratories in the United States, such as Underwriters Laboratories and FM Global, have established a consensus process that meets the requirements of the American National Standards Institute (ANSI) so that they now can publish American National Standards. 

Of the GRTP only ABS, polypropylene, poly-sulfone, and modified phenylene oxide are electroplated. Of these ABS represents about 85% of the market. Since the introduction of platable plastics, new formulations have been developed to give superior physical properties, platability, and appearance. For example, 25% glass-filled ABS has a shrinkage nearly equal to that of die-cast metals the increased stiffness reduces distortion during the plating operation and a reduction of 50% in the coefficient of linear thermal expansion permits it to pass the standard thermal cycling test of 82 to -40 C (190 to - 40 F) (Ref. 29). 

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