摘要:
A method is provided for selectively extracting the lower molecular weight fraction of a poly(arylene sulfide) polymer by contacting the polymer with a polar organic compound and a promoter compound to form a less dense polymer-lean liquid phase and a more dense polymer-rich liquid phase, separating the polymer-lean liquid phase from the polymer-rich liquid phase, and recovering the polymer from the polymer-rich phase. Alternatively, either of the phases can be isolated and polar organic compound and optionally promoter can be added to form two new phases, followed by isolation of the new polymer-rich phase. This process can be repeated as often as desired or practicable in order to recover polymer having a desired molecular weight and/or molecular weight distribution.
摘要:
Continuous, woven and non-woven glass fibers are impregnated with certain silanes before use of the fibers to make reinforced thermoplastic composites using pultrusion or compression molding. Continuous, woven and non-woven glass fiber reinforced composites are also made by concurrently combining the fibers with certain silanes and a thermoplastic matrix material using pultrusion or compression molding.
摘要:
A slurry polymerization process removes a portion of the fluid slurry without using a settling leg or a continuous take-off. The process uses a reactor take-off valve that is periodically fully closed and fully opened such that the withdrawn slurry is removed from the reactor in a discontinuous manner. The regular, periodic full closing and full opening of the take-off valve reduces instances of polymer plugging the take-off valve. In another aspect of the invention, a take-off valve is throttled in a repetitive pattern to reduce plugging of the take-off valve.