Synthesis and Characterization of Branched Polymers from Lipase-Catalyzed Trimethylolpropane Copolymerizations

Abstract

Lipase-catalyzed terpolymerizations were performed with the monomers trimethylolpropane (B3), 1,8-octanediol (B2), and adipic acid (A2). Polymerizations were performed in bulk, at 70 degrees C, for 42 h, using immobilized lipase B from Candida antartica (Novozyme-435) as a catalyst. To determine the substitution pattern of trimethylolpropane (TMP) in copolymers, model compounds with variable degrees of acetylation were synthesized. Inverse-gated 13C NMR spectra were recorded to first determine the chemical shift positions for mono-, di-, and trisubstituted TMP units and, subsequently, to determine substitution of TMP units along chains. Variation of TMP in the monomer feed gave copolymers with degrees of branching (DB) from 20% to 67%. In one example, a hyperbranched copolyester with 53 mol % TMP adipate units was formed in 80% yield, with Mw 14 100 (relative to polystyrene standards), Mw/Mn 5.3, and DB 36%. Thermal and crystalline properties of the copolyesters were studied by thermogravimetric analysis and differential scanning calorimetry.

Fabrication of dendritic 0 G PAMAM-based novel polyurea microcapsules for encapsulation of herbicide and release rate from polymer shell in different environment

“…With unique chemical and physical properties, dendrimer and hyper-branched polymers possessing reactive functional groups, three-dimensional architecture found potential stimulated applications in the various sectors of nanotechnology, supramolecular chemistry, material science, additives, automobile parts, drug delivery, surface coatings, and many more. [1][2][3][4][5][6] In recent years, field of microencapsulation has engrossed many researchers and industrialists as it causes to protect the core material from surrounding environment. Microencapsulation finds potential extensive applications in the agricultural, industrial, engineering, and medical fields such as carbonless copying paper, flame retardants, pharmaceutical applications, foods, catalysis, self-healing materials, phase change materials, and pesticides.…”

Lactone monomers obtained by enzyme catalysis and their use in reversible thermoresponsive networks

“…Star‐like polymers are of interest due to their outstanding rheological and mechanical features, which are not observed in classical linear polymers . The synthesis of four‐arm star‐like PCL was investigated by ROP of ε‐CL using di‐trimethylolpropane (Di‐TMP) multifunctional alcohol as an initiator . The polymerization was performed at 70 °C in bulk with 1,5,7‐triazabicyclo[4.4.0]dec‐5‐ene (TBD) as an organic catalyst.…”

Phosphorus-containing polymers from THPS. II: synthesis and property of phosphorus-containing hyperbranched aromatic-aliphatic polyamides

“…1 H, 13 C, and 31 P NMR spectra of the monomers and polymers were recorded using 400 MHz Bruker NMR spectrometer in DMSO-d 6 , D 2 O, and CDCl 3 containing small amount of TMS as internal standard.…”

“…Hyperbranched polymers usually have good solubility and low viscosity compared to the linear analoges. [1][2][3][4][5][6][7][8][9][10][11][12] Combining of chemically stable amide bonds with hyperbranched structures not only retained excellent thermal and flame-resistant properties of aromatic polyamides, but also decreased melt viscosity and excellent solubility which improved the processability. [13][14][15][16][17][18][19][20] Moreover, introduction of flexible aliphatic units into the main chain is another method to improve the processability of aromatic polyamides.…”