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The Gmelin rare earths handbook lists 1522 °C and 1550 °C as two melting points given in the literature, the most recent reference [Handbook on the chemistry and physics of rare earths, vol.12 (1989)] is given with 1529 °C.
The melting point for average commercial low-density polyethylene is typically 105 to 115 °C (221 to 239 °F). These temperatures vary strongly with the type of polyethylene, but the theoretical upper limit of melting of polyethylene is reported to be 144 to 146 °C (291 to 295 °F). Combustion typically occurs above 349 °C (660 °F).
The melting point of polypropylene occurs in a range, so the melting point is determined by finding the highest temperature of a differential scanning calorimetry chart. Perfectly isotactic PP has a melting point of 171 °C (340 °F). Commercial isotactic PP has a melting point that ranges from 160 to 166 °C (320 to 331 °F), depending on ...
HDPE is known for its high strength-to-density ratio. [4] The density of HDPE ranges from 930 to 970 kg/m 3. [5] Although the density of HDPE is only marginally higher than that of low-density polyethylene, HDPE has little branching, giving it stronger intermolecular forces and tensile strength (38 MPa versus 21 MPa) than LDPE. [6]
General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is a poor barrier to air and water vapor and has a relatively low melting point. [6] Polystyrene is one of the most widely used plastics, with the scale of its production being several million tonnes per year. [7]
The plastic is useful as a sample holder material in microscopy applications as its refractive index is close to that of water at visible wavelengths, [9] [10] (FEP: 1.344, water: 1.335). This minimizes the blur due to optical aberrations when the light traverses the sample container.
However, some plastics are partially amorphous and partially crystalline in molecular structure, giving them both a melting point and one or more glass transitions (the temperature above which the extent of localized molecular flexibility is substantially increased).
ASA is compatible with some other plastics, namely polyvinyl chloride and polycarbonate. ASA-PVC compounds are in use. [4] ASA can be processed by extrusion and coextrusion, thermoforming, injection molding, extrusion blow molding, and structural foam molding. [4] ASA is mildly hygroscopic; drying may be necessary before processing. [4]