Ads
related to: unsaturated polyester resin ppt
Search results
Results From The WOW.Com Content Network
Polyester resins are synthetic resins formed by the reaction of dibasic organic acids and polyhydric alcohols. Maleic anhydride is a commonly used raw material with diacid functionality in unsaturated polyester resins. [1] Unsaturated polyester resins are used in sheet moulding compound, bulk moulding compound and the toner of laser printers.
Unsaturated polyester resins are an extremely versatile, [12] [13] and fairly inexpensive class of thermosetting polymer formed by the polycondensation of glycol mixtures often containing propylene glycol, with a dibasic acid and anhydrides usually maleic anhydride to provide backbone unsaturation needed for crosslinking, and phthalic anhydride ...
BMC is manufactured by mixing strands (Greater than 1/8” and less than 2" [2] [3]) of chopped glass fibers, styrene, an initiator, and filler in a mixer with an unsaturated thermoset resin (commonly polyester resin, vinyl ester resin or epoxy resin). The mixing is done at room temperature and stored at low temperatures to slow down curing ...
Crosslinking generally involves covalent bonds that join two polymer chains. The term curing refers to the crosslinking of thermosetting resins, such as unsaturated polyester and epoxy resin, and the term vulcanization is characteristically used for rubbers. [1] When polymer chains are crosslinked, the material becomes more rigid.
Left: individual linear polymer chains Right: Polymer chains which have been cross linked to give a rigid 3D thermoset polymer. In materials science, a thermosetting polymer, often called a thermoset, is a polymer that is obtained by irreversibly hardening ("curing") a soft solid or viscous liquid prepolymer (). [1]
Sheet moulding compound (SMC) or sheet moulding composite is a ready to mould glass-fibre reinforced polyester material primarily used in compression moulding. [1] The sheet is provided in rolls weighing up to 1000 kg. Alternatively the resin and related materials may be mixed on site when a producer wants greater control over the chemistry and ...
Solvent impregnated resins (SIRs) are porous resin particles which contain an additional liquid extractant inside the porous matrix. The contained extractant is supposed to enhance the capacity of the resin particles. A large category of resins, which constitutes 75% of resins used, [citation needed] is that of the unsaturated polyester resins.
Radical disproportionation: a hydrogen atom from one chain end is abstracted to another, producing a polymer with a terminal unsaturated group and a polymer with a terminal saturated group (Figure 15). [4]