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Polyurethane synthesis, wherein the urethane groups −NH−(C=O)−O− link the molecular units A kitchen sponge made of polyurethane foam . Polyurethane (/ ˌ p ɒ l i ˈ jʊər ə ˌ θ eɪ n,-j ʊəˈr ɛ θ eɪ n /; [1] often abbreviated PUR and PU) refers to a class of polymers composed of organic units joined by carbamate (urethane) links.
Thermoplastic polyurethane (TPU) is any of a class of polyurethane plastics with many properties, including elasticity, transparency, and resistance to oil, grease, and abrasion. Technically, they are thermoplastic elastomers consisting of linear segmented block copolymers composed of hard and soft segments.
Industrial Insulation. Rigid polyurethane foam is used in various industries to provide thermal insulation to installations and pipes. In particular, the piping for district heating systems in Europe is primarily insulated using a pre-insulated pipes sandwich assembly composed of a steel heat service pipe, an insulating layer (polyurethane foam) and a polyethylene (PE) casing, which are bonded ...
PU laminate cloth is waterproof, breathes and stretches somewhat, and is soft and flexible. It can usually be machine-washed and dried, [1] and cleaned with dilute bleach or alcohol. [2] PU fabric is useful as a wind and/or water barrier in the construction of fluid-splash protecting garments, shower curtains, and outerwear clothing.
The thermal conductivity of a material is a measure of its ability to conduct heat.It is commonly denoted by , , or and is measured in W·m −1 ·K −1.. Heat transfer occurs at a lower rate in materials of low thermal conductivity than in materials of high thermal conductivity.
Crystal structure of β-glucosidase from Thermotoga neapolitana (PDB: 5IDI).Thermostable protein, active at 80°C and with unfolding temperature of 101°C. [1]In materials science and molecular biology, thermostability is the ability of a substance to resist irreversible change in its chemical or physical structure, often by resisting decomposition or polymerization, at a high relative ...
When you breathe, air flows smoothly in and out of your nose, Ramakrishnan says. But when you sneeze, you expel air and change up that flow, forcing odorous particles in your nose or throat upward ...
The bubble/foam-making process is irreversible and endothermic, i.e. it needs heat (e.g. from a melt process or the chemical exotherm due to cross-linking), to volatilize a liquid blowing agent. However, on cooling process, the blowing agent will condense, which is a reversible process. [2] [3]