METHOD AND ROTOR APPARATUS FOR PRODUCING LOW-MOLECULAR POLYISOBUTYLENE Russian patent published in 1998 - IPC

FIELD: polymer production, chemical engineering. SUBSTANCE: invention relates to methods and equipment for mixing and dispersing homogeneous media and aims at developing efficient low- molecular polyisobutylene production method at the expense of reducing multiplicity of treatment. A four-zone polyisobutylene treatment is proposed: 1st zone high-molecular polyisobutylene is heated to 100-250 C using dissipation of mechanical energy on rotation of device with speed 200-2000 rpm; 2nd zone pressure 10-80 kPa is created and temperature raised to 160-300 C resulting in initial phase of plasticized polymer destruction; 3rd zone polymer is destroyed at 250-350 C and pressure 10-90 kPa; 4th zone polymer is additionally destroyed and homogenized at 240-300 C and pressure 40-80 kPa. Narrow chain-length distribution (M_n/M_w< 3.5) of low- molecular polyisobutylene and insignificant content of volatile components are ensured by chosen design of apparatus and by short duration of thermal action upon polymer. Rotor apparatus has cylindrical casing with cooling jackets, charge and discharge pipes, executive device in the form of rotor with rolling bearing. Apparatus is also provided with closing device in the form of mushroom with its cap directed inside the apparatus to form a gap between the cap and the outlet end of worm equal to 0.2-0.5 pitch of worm. Productivity of apparatus up to 300 kg/h. EFFECT: enhanced process efficiency. 3 cl, 2 dwg, 1 tbl