Preparation of polylactic acid

Polylactic acid and copolymers thereof can be used spinning solution spinning and melt spinning process, mainly by dry spinning - heat drawing process, and dry mechanical properties of spun fibers is superior to melt spun fibers. Studies have shown that the molecular weight of magnessium lactate and its distribution, composition and concentration of the spinning solution, the stretching temperature, crystallinity and a polylactic acid fiber diameter, all influence the final properties of the fibers are thermoplastic polymers of polylactic acid, and the obtained fiber properties reducing the melt spinning before the end of the polylactic acid-OH group is not used for acetylation of acetic anhydride and pyridine, was found to improve the thermal stability, the spinning temperature lower than 200 ℃, polylactic acid substantially no thermal degradation . Two-step, the melt extrusion step, the second step heat-stretching, breaking strength can be obtained is higher than 7.2 cN / dtex polylactic acid fibers.
Polylactic acid biodegradable polymer in all the highest melting point, crystallinity, Zinc lactate, processing temperature between 170 ~ 230 ℃, good solvent resistance, it can be used for processing a variety of ways, such as extrusion pressure, spinning, biaxial stretching, injection blow molding the polylactic acid and its copolymers can be a spinning solution spinning and melt spinning process, all influence the final properties of the fibers.