Optimizing the bulk copolymerization of D,L-lactide and glycolide by response surface methodology

Abstract

Poly(D,L-lactide-co-glycolide), PLGA, is a biodegradable polyester with high interest in medical industry, especially when zinc (II) 2-ethylhexanoate (ZnOct2) is used as catalyst substitute in polymerization processes as a substitute of the toxic tin (II) 2-ethylhexanoate (SnOct2) together an initiator such as methanol to improve the reaction rate. This article shows the optimization of the bulk copolymerization method by using a factorial design approach on three experimental parameters: temperature (T), molar ratio monomers/catalyst (MC ratio) and molar ratio initiator/catalyst (IC ratio). Their influence on mass conversion (X) and number-average molecular weight (Mn) was also discussed. Also it provides a useful tool to select in a fast way the proper experimental conditions for the obtaining of this polymer as a previous stage in the synthesis and impregnation of biodegradable scaffolds. This analysis revealed that the most relevant variable in the process is the temperature, being desirable to use the high value (160ºC) in order to obtain high values of conversion and molecular weight

Synthesis and Operating Optimization of the PEG Conjugate via CuAAC in scCO2

“…A statistical experimental design based on central composite design (CCD) was used. The effects of the operating variables in the cycloaddition reaction in scCO 2 (pressure, temperature, and catalyst to alkyne group molar ratio) and their possible interactions on the yield as a response variable were studied using a 2 3 full factorial design with two central points. , The levels of each factor are indicated in Table and were selected on the basis of preliminary studies of click chemistry in scCO 2. …”

Polyester-Based (Bio)degradable Polymers as Environmentally Friendly Materials for Sustainable Development

“…PLA copolymers with PCL and/or polyglycolide (PGA) were synthesised by ring-opening polymerisation of corresponding cyclic lactones, i.e. , lactide, ε-caprolactone, or glycolide via anionic, cationic, coordination-insertion or enzymatic mechanism [ 6 , 110 , 111 ]. The synthesis of PGA/PCL copolymers were conducted using different conditions which lead to various chain microstructures and resulted in different degradation rate.…”

Improvement of PLGA loading and release of curcumin by supercritical technology

“…Operational conditions for polymerization of viable polymers in agreement with previous studies [14] were: atmospheric pressure (1 atm), temperature 130 ºC, agitation of 100 rpm and a total mass of 100 g of monomers in the reactor. The relations monomercatalyst (Stannous octoate) and catalyst-initiator are the same for both polymerizations, 90:1 and 1:2, respectively.…”

“…In order to determine the best PLGA composition for drug impregnation, in this study three different (D-L-lactide:Glycolide) molar ratios were synthetized according to a procedure previously described in bibliography by this research group [12,14]. This process involved placing monomers in a bulk reactor with catalyst and initiator at high temperature to form a viscous growing prepolymer, which after a 4 hours reaction led to a solid polymer finished when cooled to room temperature.…”