Synthesis and Characterization of a Catenated Polystyrene−Poly(2-vinylpyridine) Block Copolymer

Gan, Yaodong; Dong, Dahai; Hogen‐Esch, Thieo E.

doi:10.1021/ma0112624

Cited by 33 publications

(25 citation statements)

References 31 publications

(75 reference statements)

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“…[77][78][79][80][81][82] The general synthetic strategy consisted of a sequential anionic polymerization of two monomers yielding bisanionic A-B-A triblock copolymers which were in situ cyclized with suitable coupling agent (refer Scheme 10). The formulas of three cyclic diblock copolymers prepared in this way are compiled in Scheme 17.…”

Section: -1351-70mentioning

confidence: 99%

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Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

397

442

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Syntheses of cyclic polymers including cyclic homopolymers, cyclic block copolymers, sun-shaped polymers, and tadpole polymers are discussed on the basis of a differentiation between synthetic methods and synthetic strategies (e.g., polycondensation, ring-ring equilibration, or ring-expansion polymerization). Furthermore, all synthetic methods are classified as kinetically or thermodynamically controlled reactions. Characteristic properties of cyclic polymers such as smaller hydrodynamic volume, lower melt viscosities, and higher thermostabilities are compared to the properties of their linear counterparts. Furthermore, the nanophase separation of cyclic diblock copolymers is discussed.

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Section: -1351-70mentioning

confidence: 99%

“…80 Moreover, the preparation of a catinated kind of block-copolymers is worth noting. 82 Bisanionic poly(2-vinyl pyridine) was cyclized in a THF solution containing preformed cyclic polystyrene. Both cyclic polymers had M n s around 5 kDa.…”

Section: -1351-70mentioning

confidence: 99%

Cyclic polymers: Synthetic strategies and physical properties

Kricheldorf

2009

J. Polym. Sci. A Polym. Chem.

397

442

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“…The “a 2 +b 2 ” (poly)condensation of bisanionic homopolymers at low iMC also proved useful for the preparation of cyclic diblockcopolymers 77–82. The general synthetic strategy consisted of a sequential anionic polymerization of two monomers yielding bisanionic A‐B‐A triblock copolymers which were in situ cyclized with suitable coupling agent (refer Scheme ).…”

Section: Kinetically‐controlled Polycondensationsmentioning

confidence: 99%

Distinct topography of erosion and new bone formation in achilles tendon enthesitis: Implications for understanding the link between inflammation and bone formation in spondylarthritis

McGonagle¹,

Wakefield²,

Tan³

et al. 2008

Arthritis & Rheumatism

112

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Objective. This study combined ultrasonography of the Achilles tendon enthesis at different stages of spondylarthritis (SpA) with microanatomic studies of normal cadaveric entheses, with the aim of exploring the relationship between bone erosion and new bone formation in enthesitis.Methods. Thirty-seven patients with SpA and Achilles tendon enthesitis (20 with early SpA and 17 with chronic SpA) and 10 normal control subjects underwent ultrasound scanning. The presence of bone erosion and spur formation was recorded at 3 sites: the proximal and distal halves of the enthesis and the adjacent calcaneal superior tuberosity. Parallel histologic analysis was performed on cadaveric Achilles tendon entheses to determine whether regional variations in bone density and trabecular architecture in relation to fibrocartilage distribution are related to disease patterns.Results. Bone erosion in patients with early SpA occurred at either the proximal insertion or the superior tuberosity (11 of 20 patients; P < 0.001 versus distal enthesis). Very small spurs, which were present almost exclusively at the distal enthesis, were evident in patients with early SpA and in normal control subjects. However, large spurs were evident distally only in patients with chronic SpA (9 of 17 patients, compared with none of 20 patients with early SpA; P < 0.0001). Histologic studies showed that aged normal individuals had small spurs at the corresponding location. The bone-to-marrow ratio was also significantly lower in the regions prone to erosions (P < 0.05).Conclusion. Bone erosion in association with Achilles tendon enthesitis in SpA is anatomically uncoupled from bone formation-the 2 processes are topographically and temporally distinct. We thus conclude that disease patterns in SpA are related to normal enthesis structure and biomechanics.

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“…Recently, the ring copolymers with a θ shape [6], 8 shape [7,8], and tadpole shape [9] have been synthesized by a combination of living polymerization and click chemistry. Two single-rings can be catenated together to form a double-ring topology, which has also been synthesized recently [10][11][12]. Rather than chemical bonds, the two rings of the double-ring polymers are locked by topological constraints.…”

Section: Introductionmentioning

confidence: 99%

Monte Carlo simulations on thermodynamic and conformational properties of catenated double-ring copolymers

Sun

Cho

2014

Phys. Rev. E

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The thermodynamic and conformational properties of catenated double-ring A-B copolymer melts are investigated through lattice Monte Carlo simulations. The topological constraint on the catenated copolymers is shown to suppress demixing of A and B monomers. This action results in their order-to-disorder transition (ODT) at an increased segregation level and the lamellae below ODT with reduced order, when compared to diblock copolymers of linear or single-ring topology. The A and B rings are pulled closer by catenation in the copolymer, which leads to its smaller gyration radius, lamellar domain spacing, and distance between mass centers of the two rings than for the diblock copolymers. With increasing segregation tendencies, the gyration radii of the A rings of the catenated copolymers stretch along the direction normal to lamellae, while the A-block conformations of the single-ring copolymers change their shapes from ellipsoid to sphere.

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Synthesis and Characterization of a Catenated Polystyrene−Poly(2-vinylpyridine) Block Copolymer

Cited by 33 publications

References 31 publications

Cyclic polymers: Synthetic strategies and physical properties

Cyclic polymers: Synthetic strategies and physical properties

Distinct topography of erosion and new bone formation in achilles tendon enthesitis: Implications for understanding the link between inflammation and bone formation in spondylarthritis

Monte Carlo simulations on thermodynamic and conformational properties of catenated double-ring copolymers

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