GP is a thermoplastic and viscoelastic material which is temperature sensitive. PHYSICAL AND THERMO-MECHANICAL PROPERTIES The beta form becomes amorphous when heated at 56☌, which is a considerable 9° less than the melting point of the alpha form and the factor determining the melting point of “alpha” and “beta” GP is the rate of cooling which, in turn, controls the extent and character of crystallinity in the material formed. If this amorphous material is cooled rapidly, β form recrystallizes whereas if it is cooled extremely slowly (0.5☌/h), α form recrystallizes. When the alpha form is heated >65☌, it becomes amorphous and melts. Most of the commercially available products are in the “beta” form. The “alpha” form occurs in the tree, which is the natural form. These forms were “trans” isomer, differing only in single bond configuration and molecular repeat distance, and hence could be converted into each other. It requires a special technology where all ingredients are blended and passed through the specification molds running under high vacuum suction or by injection molding and hand rolling.Ĭ.W Bunn in the year 1942, reported that the GP polymer could exist in two distinctly different crystalline forms, which he termed “alpha” and “beta” modifications. However, to make endodontic cones, the precision of standardization has to be maintained. It is relatively easy to make GP sticks as not much of precision is required. When it occurs in gutta in larger quantities it renders this material brittle. Fluavil is a lemon-yellow, amorphous body, having the composition (C 10H 16O). Alban does not seem to have any harmful effect on the technical properties of GP. The elasticity of GP and its plasticity at elevated temperature is determined by Gutta.
In crude form, its composition is made of Gutta (75%–82%), Alban (14%–16%), Fluavil (4%–6%), and also tannin, salts, and saccharine. It is finally combined with fillers, radiopaque material, and plasticizers to obtain GP cones for endodontic procedures with the composition of 20% GP, 56% zinc oxide filler, 11% radiopacifier (barium sulfate), and 3% plasticizers (waxes or resins). Its use multiplied rapidly for manufacture of corks, pipes cements, thread, surgical instruments, garments, musical instruments, suspenders, window shades, carpets, gloves, mattresses, pillows, tents, umbrellas, golf balls (gutties), sheathing for ships, and boats were made wholly of GP. People became infatuated with this new material and it became the first successful insulation for an underwater cable. In 1845, Hancock and Bewley formed the GP Company in United Kingdom. The first patent for GP was obtained in 1864 by Alexander, Cabriot, and Duclos, which opened a Broadway for its industrial use. His work was referred to the Medical Board of Calcutta and was awarded a gold medal by The Royal Society of Arts in London. William Montgomerie further introduced GP to the West.
Around 1656 an English natural historian John Tradescant introduced GP to Europe and called it “mazer wood.” In 1843, Dr. History shows that GP has been used for a variety of purposes since the 17 th century.
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