Synthesis and characterization of a novel functional biodegradable material, poly(lactic acid-co-borneol)

Abstract

Directly starting from D,L-lactic acid (LA) and L-borneol, novel biodegradable material poly(lactic acid-co-borneol) (PLAB) was synthesized via melt polycondensation. When the molar feed ratio LA/borneol is 64/1, the influences of different conditions including catalyst kinds and its dosage, copolymerization time, and temperature on the synthesis of the polymer are discussed. When the SnO was used as catalyst and the dosage was 0.3 wt% of the prepolymer, the 5 h direct melt polycondensation at 170°C and absolute pressure of 70 Pa after prepolymerization gave the copolymer with the maximum intrinsic viscosity [η], 1.51 dL g À1 . The structure of copolymer was confirmed by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H-NMR). According to the appropriate synthetic conditions, the copolymers with different molar feed ratios were synthesized and systematically characterized by [η], gel permeation chromatography (GPC), differential scanning calorimetry, thermogravimetric, and X-ray diffraction (XRD). The GPC results show that the maximum weight average molecular weight (M w ) of PLAB is 11,900, when the molar feed ratio LA/borneol is 64/1. With the increase of the molar feed ratio of borneol, [η], M w and its polydispersity index (M w /M n ) increase gradually. Due to the introduction of borneol into the copolymer, the glass-transition temperature (T g ) decreases gradually with the increasing feed ratio of borneol. The direct melt copolycondensation is a cheap and practical method for the synthesis of borneol modified polylactic acid, a potential solid borneol flavor, polymeric drug, and functional drug carrier.

Synthesis and characterization of a novel drug-loaded polymer, poly(lactic acid-co-aminomethyl benzimidazole)

“…[29,30,[34][35][36]48] As reported in the literature, [49][50][51] the PLAs material with a molecular weight of 1800 Da can be applied in drug delivery, even PLA copolymers with a molecular weight of only 900 Da can be used as drug delivery device. In this study, the molecular weights of PLAAMBs are between 3100 and 9400 Da (Tables 1-5), each one of them is overwhelmingly higher than 900 Da.…”

“…[24][25][26][27] Therefore, the studies on the low-cost synthesis of PLA materials via direct melt polycondensation and their practical applications in the field of drug delivery have received great attention in recent years. [28][29][30][31][32][33][34][35][36][37] However, there is no report about the drug delivery of benzimidazole drugs loaded by PLA materials. Herein, on the basis of our previous studies on lactic acid (LA) direct melt polymerization [35,38,39] and benzimidazole compounds, [3][4][5][6] using AMB [10] as a model of benzimidazole-type drugs, poly(lactic acid-coaminomethyl benzimidazole) (PLAAMB) as a potential biodegradable drug-loaded polymer is designed, and synthesized (Scheme 1).…”

“…[28][29][30][31][32][33][34][35][36][37] However, there is no report about the drug delivery of benzimidazole drugs loaded by PLA materials. Herein, on the basis of our previous studies on lactic acid (LA) direct melt polymerization [35,38,39] and benzimidazole compounds, [3][4][5][6] using AMB [10] as a model of benzimidazole-type drugs, poly(lactic acid-coaminomethyl benzimidazole) (PLAAMB) as a potential biodegradable drug-loaded polymer is designed, and synthesized (Scheme 1). After the discussions on the optimal synthetic conditions, the structures and basic properties of PLAAMBs with different molar feed ratios are systematically investigated by Fourier transform infrared (FT-IR), 1 H NMR, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and X-ray diffraction (XRD).…”

Design, synthesis, and characterization of a potential flame retardant poly(lactic acid‐co‐pyrimidine‐2,4,5,6‐tetramine) via direct melt polycondensation

“…According to the previous work on melt copolymerization of LA, LA, and PTA should be prepolymerized before copolymerization. After LA and PTA were uniformly mixed as preplanned molar feed ratio, the obtained mixture was directly dehydrated for 8 h at 140°C under 4000 Pa in a flask equipped with mechanical stirring and thermometer.…”

Controlled release of borneol from nano-fibrous poly(L-lactic acid)/ cellulose acetate butyrate membrane

“…4 In contrast with physical methods, a chemical method via the esterification of borneol was also studied, with small organic molecules and with polymeric materials. 5 In recent years, electrospinning has been widely used to make ultrafine fibers with small diameters and large surface areas. Electrospun nano-fibrous nonwoven polymers with proteins or other growth factors have been used as a natural extracellular matrix for tissue engineering to promote cell adhesion, migration and proliferation.…”