Polyoxazoline containing copolymers useful as emulsifiers for polymer blends

Abstract

The preparation of new block and graft copolymers containing poly (2‐alkyloxazoline)s using macroinitiator methods have been investigated. Hydroxy terminated poly(2‐alkyloxazoline) oligomers can be synthesized using alkyl iodide initiators and potassium hydroxide as the terminating reagent. Polymerizations of ϵ‐caprolactone using monofunctional poly(2‐alkyloxazoline)s as macroinitiators and Sn(oct)2 as the catalyst yield diblock copolymers of poly(2‐alkyloxazoline‐b‐ϵ‐caprolactone) with controlled molecular weights. Graft copolymers have also been prepared by first generating a poly(alkyl vinyl ether) backbone. Copolymerization of a low molar percentage of 2‐chloroethyl vinyl ether with alkyl vinyl ethers was performed using a heterogeneous cationic catalyst to yield high molecular weight random copolymers with pendent ethyl chloride groups interspersed along the chain. This pendent chlorine group, together with NaI, was used as the initiation system for 2‐alkyloxazoline grafts. Characterization of the resultant copolymers by gel permeation chromatography, intrinsic viscosity, DSC, solution and solid state 1H and 13C NMR is discussed. These materials are being evaluated as emulsifiers for polymer blends containing aliphatic polyamides as one component.

Evaluation of Blood Clearance Rates and Biodistribution of Poly(2-oxazoline)-Grafted Liposomes§

“…The first method adapted from Kobayashi et al 18 involved addition of solid sodium carbonate and water and heating the reaction mixture at 80°C for 6 h. Alternatively, a methanolic solution of KOH (0.5 M) was added to the polymerization mixture followed by stirring at 25°C for 2 h according to the procedure of Riffle and co-workers. 19 When ethyl 3-bromopropionate was used as initiator, addition of 2.5 equiv of KOH caused both termination and formation of a carboxyl group by hydrolysis of the ethyl ester at the initiation end of the polymer. Purification of the polymers was accomplished by water dilution of the terminated mixtures to 50 mL and dialysis against 50 mM NaCl, 2% acetic acid, and water (3 × 3 L each) using 3500 molecular weight cutoff Specrta/Por dialysis membrane (Spectrum, Los Angeles, CA).…”

“…The polymers were further characterized according to the well-established protocols. [18][19][20] Preparation of POZ-DSPE ConjugatessCarboxylated POZ (0.3 mmol of either glutarate or propionate end groups) was dissolved in chloroform (10 mL) and treated with N-hydroxysuccinimide (0.4 mmol) and dicyclohexylcarbodiimide (0.4 mmol). The solution was stirred overnight at 25°C and then filtered from precipitated dicyclohexylurea.…”

Polymer Blends

“…Copolymers of styrene with a functional oxazoline monomer can react with carboxyl-, amino-, or anhydride-functional polymers to produce graft copolymers [128]. This reactive PS has been used to compatibilize the combination of PPE and an ethylene -acrylic acid copolymer, producing a high-impact engineering blend with excellent strength and processing properties.…”

Functionalized Thermo‐Responsive Poly(vinyl ether) by Living Cationic Random Copolymerization of Methyl Vinyl Ether and 2‐Chloroethyl Vinyl Ether

“…[5] The behaviour of vinyl ether-based copolymers in water can be modified in different ways. [3,6,7] Recently, Aoshima et al have discovered sharp thermo-responsive behaviour of poly(vinyl ethers) with pendant oxyethylene units, poly(2-ethoxyl ethyl vinyl ether), [8] and v-alkyl groups, poly(4-hydroxybutyl vinyl ether), [9] prepared by living cationic polymerization.…”

“…For example, nucleophilic substitution reactions of its pendant chlorine groups yield a variety of functionalized polymers. [7,22,23] First, the copolymerization conditions such as the reaction temperature and the concentration of the activator had to be optimized because the homopolymerizations proceed at different temperatures (0 8C for MVE [24] and À40 8C for CEVE [25,26] ). Then, it was investigated whether the random copolymerization showed the same characteristics as the living homopolymerizations.…”