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Plastic is not sold as a pure unadulterated substance, but is instead mixed with various chemicals and other materials, which are collectively known as additives. These are added during the compounding stage and include substances such as stabilizers , plasticizers and dyes , which are intended to improve the lifespan, workability or appearance ...
When extruded into a filament, ABS plastic is a common material used in 3D printers, [26] as it is cheap, strong, has high stability and can be post-processed in various ways (sanding, painting, gluing, filling and chemical smoothing). When being used in a 3D printer, ABS is known to warp due to shrinkage that occurs while cooling during the ...
The presence of chloride groups gives the polymer very different properties from the structurally related material polyethylene. [17] At 1.4 g/cm 3, PVC's density is also higher than structurally related plastics such as polyethylene (0.88–0.96 g/cm 3) and polymethylmethacrylate (1.18 g/cm 3).
Each bead is made of thin-walled, air-filled bubbles of polystyrene. Expanded polystyrene (EPS) is a rigid and tough, closed-cell foam with a normal density range of 11 to 32 kg/m 3. [47] It is usually white and made of pre-expanded polystyrene beads. The manufacturing process for EPS conventionally begins with the creation of small polystyrene ...
When pure, the dielectric constant is in the range 2.2 to 2.4 depending on the density [21] and the loss tangent is very low, making it a good dielectric for building capacitors. For the same reason it is commonly used as the insulation material for high-frequency coaxial and twisted pair cables.
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]
Otto Bayer in 1952 demonstrating his creation. Otto Bayer and his coworkers at IG Farben in Leverkusen, Germany, first made polyurethanes in 1937. [5] [6] The new polymers had some advantages over existing plastics that were made by polymerizing olefins or by polycondensation, and were not covered by patents obtained by Wallace Carothers on polyesters. [7]
LDPE has SPI resin ID code 4 Schematic of LDPE branching structure. Low-density polyethylene (LDPE) is a thermoplastic made from the monomer ethylene.It was the first grade of polyethylene, produced in 1933 by John C. Swallow and M.W Perrin who were working for Imperial Chemical Industries (ICI) using a high pressure process via free radical polymerization. [1]