Synthesis and Characterization of Poly(methyl methacrylate‐co‐hydroxyethyl methacrylate)‐b‐polyisobutylene‐b‐poly(methyl methacrylate‐co‐hydroxyethyl Methacrylate) Triblock Copolymers

Abstract

The synthesis of poly[(methyl methacrylate-co-hydroxyethyl methacrylate)-b-isobutylene-b-(methyl methacrylate-co-hydroxyethyl methacrylate)] P(MMA-co-HEMA)-b-PIB-b-P(MMA-co-HEMA) triblock copolymers with different HEMA/MMA ratios has been accomplished by the combination of living cationic and anionic polymerizations. P(MMA-co-HEMA)-b-PIB-b-P(MMA-co-HEMA) triblock copolymers with different compositions were prepared by a synthetic methodology involving the transformation from living cationic to anionic polymerization. First, 1,1-diphenylethylene end-functionalized PIB (DPE-PIB-DPE) was prepared by the reaction of living difunctional PIB and 1,4-bis(1-phenylethenyl)benzene (PDDPE), followed by the methylation of the resulting diphenyl carbenium ion with dimethylzinc (Zn(CH 3 ) 2 ). The DPE ends were quantitatively metalated with n-butyllithium in tetrahydrofuran, and the resulting macroanion initiated the polymerization of methacrylates yielding triblock copolymers with high blocking efficiency. Microphase separation of the thus prepared triblock copolymers was evidenced by the two glass transitions at 264 and þ1208C observed by differential scanning calorimetry. These new block copolymers exhibit typical stress-strain behavior of thermoplastic elastomers. Surface characterization of the samples was accomplished by angle-resolved X-ray photoelectron spectroscopy (XPS), which revealed that the surface is richer in PIB compared to the bulk. However, a substantial amount of P(MMA-co-HEMA) remains at the surface. The presence of hydroxyl functionality at the surface provides an opportunity for further modification.

Peptide Surface Modification of P(HEMA-co-MMA)-b-PIB-b-P(HEMA-co-MMA) Block Copolymers

“…The syntheses of block copolymers, P[HEMA(25)- co -MMA(75)]- b -PIB- b -P[MMA(75)- co -HEMA(25)] (P1), P[HEMA(50)- co -MMA(50)]- b -PIB- b -P[MMA(50)- co -HEMA(50)] (P2), P[HEMA(75)- co -MMA(25)]- b -PIB- b -P[MMA(25)- co -HEMA(75)] (P3), and PHEMA- b -PIB- b -PHEMA (P4) have been described elsewhere . The polymers exhibited the following characteristics: P1: M n = 110 800; PD = 1.21; PIB wt % = 55.5.…”

A Renaissance in Living Cationic Polymerization

“…DDPE end-functionalized PIB was also prepared from the reaction of living PIB and DDPE. , The PIB-DDPE was quantitatively metalated with BuLi in THF at room temperature, and the macroinitiators could initiate the various living anionic polymerizations of methacrylate monomers, yielding diblock copolymers with high block efficiency. Synthesis of triblock copolymer poly(MMA- co -HEMA)-PIB-poly(MMA- co -HEMA) can be investigated by use of metalated DDPE-PIB-DDPE ( 80 ) …”

Comprehensive Characterization of Grafted Expanded Poly(tetrafluoroethylene) for Medical Applications

“…It is therefore important to determine the depth of penetration of the copolymer into the pores and/or into the bulk of the substrate. Methods commonly employed to determine depth of penetration include scanning electron microscopy (SEM), pseudo confocal Fourier transform infrared spectroscopy (FTIR), , Raman spectroscopy, , dye assays, , angle-dependent X-ray photoelectron spectroscopy (XPS), − and confocal laser scanning microscopy . SEM, Raman, FTIR, and dye assays all require destructive sample preparation, such as resin embedding or cross-sectioning, which can cause the introduction of artifacts.…”