Synthesis and characterization of poly(ethylene glycol)/poly(l-lactic acid) alternating multiblock copolymers

Huh, Kang Moo; Bae, You Han

doi:10.1016/s0032-3861(98)00822-2

Cited by 123 publications

(78 citation statements)

References 24 publications

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“…The proton peaks of SA (δ = 2.7 ppm) were observed from the resultant polymer by 1 H-NMR. This result coincides with several earlier studies of PLA-PEG multiblock copolymers [17][18][19]. Scheme 1.…”

Section: Synthesis Of Multiblock Copolymerssupporting

confidence: 92%

Size-Controlled Nanomicelles of Poly(lactic acid)–Poly(ethylene glycol) Copolymers with a Multiblock Configuration

et al. 2015

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Abstract:The ability to control the micelle size of poly(lactic acid) and poly(ethylene glycol) (PLA-PEG) block copolymers is important for controlling their circulation in blood cell recognition, drug release and therapeutic effects. We successfully controlled the micelle size by changing the block number of copolymers (multiblock index). PLA-PEG multiblock copolymers with multiblock indexes ranging from 1.35 to 2.78 were synthesized by direct polycondensation with tin chloride/p-toluenesulfonic acid binary catalysts, using PEG with a molecular weight (Mw) of 3200 Da. The Mw of PLA-PEG copolymers increased with an increase in the multiblock index, while micelle size, measured by dynamic light scattering, decreased greatly from 349 to 28 nm. In addition, the X-ray diffraction peak of the PLA crystal disappeared when the multiblock index was increased. These results indicate that a multiblock structure is useful for controlling micelle size without changing the PLA/PEG composition or PEG molecular weight, which strongly influences other micelle features.

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Section: Synthesis Of Multiblock Copolymerssupporting

confidence: 92%

Size-Controlled Nanomicelles of Poly(lactic acid)–Poly(ethylene glycol) Copolymers with a Multiblock Configuration

et al. 2015

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“…Arguably the most noted property of multiblock copolymers is their ability to self-assemble into ordered microstructures when the segments are sufficiently long [1,2]. The microphase separation of multiblock copolymers with long alternating hard and soft segments gives rise to their unique material properties as thermoplastic elastomers [3,4]. Other industrial uses of the bulk polymers include the utilization as compatibilizers [5,6] for blends of otherwise immiscible homopolymers and as pressure-sensitive adhesives [7,8].…”

Section: Introductionmentioning

confidence: 99%

Multiblock Copolymers of Styrene and Butyl Acrylate via Polytrithiocarbonate-Mediated RAFT Polymerization

Ebeling

Vana

2011

Polymers

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Abstract:When linear polytrithiocarbonates as Reversible Addition-Fragmentation chain Transfer (RAFT) agents are employed in a radical polymerization, the resulting macromolecules consist of several homogeneous polymer blocks, interconnected by the functional groups of the respective RAFT agent. Via a second polymerization with another monomer, multiblock copolymers-polymers with alternating segments of both monomers-can be prepared. This strategy was examined mechanistically in detail based on subsequent RAFT polymerizations of styrene and butyl acrylate. Size-exclusion chromatography (SEC) of these polymers showed that the examined method yields low-disperse products. In some cases, resolved peaks for molecules with different numbers of blocks (polymer chains separated by the trithiocarbonate groups) could be observed. Cleavage of the polymers at the trithiocarbonate groups and SEC analysis of the products showed that the blocks in the middle of the polymers are longer than those at the ends and that the number of blocks corresponds to the number of functional groups in the initial RAFT agent. Furthermore, the produced multiblock copolymers were analyzed via differential scanning calorimetry (DSC). This work underlines that the examined methodology is very well suited for the synthesis of well-defined multiblock copolymers.

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“…The columns were TSK gel G4000HXL and a TSK gel G3000HXL with a limited exclusion molecular weight of 4x10 5 . The eluent was CHCl 3 and the flow rate was 0.6 ml/min (Huh, 1999;Hyon, 1997). …”

Section: Gel Permeation Chromatographymentioning

confidence: 99%

Synthesis and characterization of copoly(L-lactic acid-caprolactone) and its stereo-effect with poly D-lactic acid and biodegradability

Hoque

Nakayama

Nur

et al. 2012

Bangladesh J. Sci. Ind. Res.

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Random copolymerizations of L-Lactide with ε-Caprolactone by ring opening polymerization reactions were carried out. A number of copolymers were formed and observed that any composition of copolymer can be formed by changing the feed ratio of the respective monomers. The effect of temperature and time in copolymerization reaction were studied. For their characterization, NMR, IR, DSC and GPC were measured. The stereo-effect of the lactic acid based biodegradable polymers and copolymers for improve thermo-mechanical properties were studied. The obtained copolymers also show stereo-effect like homopolymer. The biodegradability of obtained polymers, copolymers and stereocomplex were studied in three different biodegradation methods; e.g., Enzymatic method, Composting method and Activated Sludge treatment method; and compared to each other.

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Synthesis and characterization of poly(ethylene glycol)/poly(l-lactic acid) alternating multiblock copolymers

Cited by 123 publications

References 24 publications

Size-Controlled Nanomicelles of Poly(lactic acid)–Poly(ethylene glycol) Copolymers with a Multiblock Configuration

Size-Controlled Nanomicelles of Poly(lactic acid)–Poly(ethylene glycol) Copolymers with a Multiblock Configuration

Multiblock Copolymers of Styrene and Butyl Acrylate via Polytrithiocarbonate-Mediated RAFT Polymerization

Synthesis and characterization of copoly(L-lactic acid-caprolactone) and its stereo-effect with poly D-lactic acid and biodegradability

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