Highly random copolymers of c-caprolactone (CL) and D,L-lactide (LA) were synthesized by a new catalyst system, rare earth chloride-propylene oxide (PO) system. In the presence of propylene oxide, all rare earth chlorides tested are highly effective for the copolymerization. The influences of reacti
Synthesis and characterization of random hydrophilic/hydrophobic copolymers of styrene and D-lactose-O-vinylbenzylhydroxime
β Scribed by Wen-Jing Zhou; Sarita S. Naik; Mark J. Kurth; You-Lo Hsieh; John M. Krochta
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 157 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0887-624X
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β¦ Synopsis
D-Lactose-O-(vinylbenzyl)oxime (LVO), prepared from β£-D-lactose and [O-(vinylbenzyl)oxy]amine (1) was copolymerized with styrene (ST) in dimethylsulfoxide (DMSO)-toluene (1 : 1, v/v) at 65Β°C using 2,2Π-azobisisobutyronitrile (AIBN) as a free radical initiator. The polymerization was rapid when using AIBN as the initiator. The resultant copolymers were characterized by elemental analyses, infrared, viscometry, TGA, DSC, and 1 H-NMR spectroscopy. The poly(ST-co-LVO) had an intrinsic viscosity in the range of 0.11-0.51 dL/g in DMSO at 30Β°C. The molecular weight was determined by gel permeation chromatography (GPC), and the molecular weight of the resulting polymers ranged from 2.11 Ο« 10 4 to 6.53 Ο« 10 7 with low polydispersities. The solubility of the copolymers with different monomer compositions in solvents of varied polarities was also studied. Incorporation of up to 65% (mol %) of lactose-based monomer onto polystyrene backbone led to a water-soluble polymer. Thermal behavior of the synthesized copolymers was evaluated by thermogravimetric analysis (TGA) and correlated very well with the polymer composition. Introduction of a pendant disaccharide compromised the thermal stability of the copolymer. The synthetic approach described in this report provides a route to prepare a novel disaccharide surfactant polymer with well-defined structures and hydrophilic/hydrophobic balances, by adjusting feed ratio of the lactose-based monomer (1) to styrene.
π SIMILAR VOLUMES
The radical homopolymerization of styrene or copolymerization of styrene (S) with N-butyl maleimide (I) initiated by tetraethylthiuram disulfide was used to prepare macroinitiators having thiyl end groups. The S-I copolymers from the feeds containing 30-70 mol % I showed approximately alternating co
Random copolymers of poly(ethylene terephthalate) (PET) and poly(ethylene 2,6-naphthalate) (PEN) were synthesized by melt condensation. In a series of thin, solvent cast films of varying PEN content, acetone diffusivity and solubility were determined at 35Β°C and an acetone pressure of 5.4 cm Hg. The