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Melting point: 260–270 °C; 500 ... Cellulose is used to make water-soluble ... but still compete with food crops for agricultural land and water resources. [72 ...
The following chart shows the solubility of various ionic compounds in water at 1 atm pressure and room temperature (approx. 25 °C, 298.15 K). "Soluble" means the ionic compound doesn't precipitate, while "slightly soluble" and "insoluble" mean that a solid will precipitate; "slightly soluble" compounds like calcium sulfate may require heat to precipitate.
A polymer (/ ˈ p ɒ l ɪ m ər / [4] [5]) is a substance or material that consists of very large molecules, or macromolecules, that are constituted by many repeating subunits derived from one or more species of monomers. [6]
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).
Polyglycolide has a glass transition temperature between 35 and 40 °C and its melting point is reported to be in the range of 225 to 230 °C. PGA also exhibits an elevated degree of crystallinity, around 45–55%, thus resulting in insolubility in water. [2]
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]
Although it is widely believed that this phase transition occurs at 32 °C (90 °F), [3] the actual temperatures may differ 5 to 10 °C (or even more) depending on the polymer concentration, [3] molar mass of polymer chains, polymer dispersity as well as terminal moieties.
PHAs are soluble in halogenated solvents such chloroform, dichloromethane or dichloroethane. [16] PHB is similar in its material properties to polypropylene (PP), has a good resistance to moisture and aroma barrier properties. Polyhydroxybutyric acid synthesized from pure PHB is relatively brittle and stiff.