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Study on the Catalytic Behaviors of β-diketone Ti、Zr in Ring-Opening Polymerization of Lactide

Author: ChengJin
Tutor: SunJunQuan
School: Zhejiang University
Course: Chemical Engineering
Keywords: Lactide Polylactic acid β-diketones , titanium, zirconium complexes Ring-opening polymerization Bulk polymerization Solution polymerization
CLC: TQ316.341
Type: Master's thesis
Year: 2006
Downloads: 118
Quote: 0
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Abstract


Polylactic acid is a biodegradable environmentally friendly polymer materials are widely used in the field of pharmaceutical packaging , and thus the catalytic synthesis of poly ( lactic acid ) has been the hot spot of concern , and thus the catalytic lactide ring-opening polymerization catalyst is always a good topic to have important academic value and application background . The paper on the basis of the existing literature , the improved synthetic four catalysts: titanium acetylacetonate (Cat1 ) , of benzoylacetone titanium ( Cat2 ) dibenzoylmethane , titanium (Cat3) acetylacetonate zirconium ( CAT4 ) , and the introduction of a new Schiff bases catalyst (Cat5), and determined by elemental analysis and NMR analysis . Then as a catalyst were ring-opening polymerization of lactide bulk ring-opening polymerization and solution , and focus on the Cat1 ~ 5 catalytic lactide body of ring-opening polymerization Cat4 catalytic lactide solution ring-opening polymerization made ??the following research : ① the influence of different catalysts on the polymerization performance ; ② the amount of catalyst (i.e. the monomer ratio of [La] / [ CAT] ) , the polymerization time and the polymerization temperature on the polymerization performance . ③ solution polymerization , the monomer concentration and solvent of the polymerization . The study shows that : ① zirconium-based activity of the catalyst is stronger than the titanium-based catalyst ; ② metal center steric hindrance of the ligand group that would increase the polymerization conversion decreases , resulting polylactic acid decrease in molecular weight , molecular weight distribution is narrowed ; ③ In the bulk polymerization conditions , the polymerization conversion rate at 95% or more , the resultant viscosity-average molecular weight of up to 6.792 x 10 ~~ 4 , the the ④ solution polymerization , the polymerization conversion rate and the resulting polylactic acid molecular weight are not such as bulk polymerization .

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CLC: > Industrial Technology > Chemical Industry > Molecular compound Industries ( polymer industry ) > Production process > Polymerization process. > Ring-opening polymerization
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