Comparison of Poly(Ethylene Oxide) Melt Crystallization in Blend and Block Copolymer Systems with Poly (Methyl Methacrylate) and Poly (Tert-Butyl Methacrylate)

Unger, R.; Reuter, H.; Höring, S.; Donth, E.

doi:10.1080/03602559008049832

Cited by 9 publications

(9 citation statements)

References 16 publications

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“…This depression of crystallinity resulting from tethering both ends of the crystallizable chain to a hard wall is similar to that reported by Unger et al for the PEO-PtBMA system. 35 Most of the lower molecular weight VEV samples have similar degrees of crystallinity, in a range from 21 to 30%, with one exception. The crystallinity of the VEV-7 sample (w E ϭ 0.145; spheres) is somewhat lower, only 17%.…”

Section: Transmission Electron Microscopymentioning

confidence: 97%

“…The crystallinity of a PEO-PtBMA diblock with approximately 50 wt % PEO was greater than that of the analogous Pt-BMA-PEO-PtBMA triblock, and was much greater than that of a three-arm PtBMA-PEO starblock with PtBMA end blocks. For a series of PEO-PtBMA diblocks in which the PtBMA block length was kept constant while the PEO block length was varied, Unger et al 35 also reported that crystallinity increased with increasing PEO weight fraction. We note that in these reports 34,35 no studies of block copolymer mesophase structure were performed.…”

Section: Introductionmentioning

confidence: 96%

“…For a series of PEO-PtBMA diblocks in which the PtBMA block length was kept constant while the PEO block length was varied, Unger et al 35 also reported that crystallinity increased with increasing PEO weight fraction. We note that in these reports 34,35 no studies of block copolymer mesophase structure were performed.…”

Section: Introductionmentioning

confidence: 96%

“…For a series of PEO-PS- PEO triblocks with a constant molecular weight of 9000 g/mol, the crystallinity of the PEO block was found to decrease from 80% for a triblock with 20 wt % styrene to approximately 35% for a triblock with 80 wt % styrene. 34 Unger et al 35 studied a series of phase-separated poly(ethylene oxide)-poly(t-butyl methacrylate) (T g , PtBMA Ϸ 110°C) blends and block copolymers, concluding that the presence of free PEO chain ends enhances crystallinity. The crystallinity of a PEO-PtBMA diblock with approximately 50 wt % PEO was greater than that of the analogous Pt-BMA-PEO-PtBMA triblock, and was much greater than that of a three-arm PtBMA-PEO starblock with PtBMA end blocks.…”

Section: Introductionmentioning

confidence: 98%

See 3 more Smart Citations

Crystallization of tethered polyethylene in confined geometries

Weimann

Hajduk

Chu

et al. 1999

J. Polym. Sci. B Polym. Phys.

105

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Section: Transmission Electron Microscopymentioning

confidence: 97%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 98%

See 2 more Smart Citations

Crystallization of tethered polyethylene in confined geometries

Weimann

Hajduk

Chu

et al. 1999

J. Polym. Sci. B Polym. Phys.

105

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“…In this article, we report the crystallization behavior of methacrylic and acrylic graft copolymers having crystallizable PEG chains grafted on the amorphous main chain: PMMA‐ graft ‐PEG and PMAc‐ graft ‐PEG. It should be noted that PMMA/PEG and PMAc/PEG polymer blends are reported to be miscible above the T m for PEG,23–28 therefore, the main and side chains in these graft copolymers are expected to be molecularly homogeneous when PEG is melted. The effect of large differences in the T g of the main chain block on the crystallization behavior and packing manner of chains after the crystallization has been examined.…”

Section: Introductionmentioning

confidence: 99%

Side‐chain crystallization behavior of graft copolymers consisting of amorphous main chain and crystalline side chains: Poly(methyl methacrylate)‐graft‐poly(ethylene glycol) and poly(methyl acrylate)‐graft‐poly(ethylene glycol)

Inomata¹,

Nakanishi²,

Sakane³

et al. 2004

J Polym Sci B Polym Phys

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Graft copolymers consisting of amorphous main chain, poly(methyl methacrylate) (PMMA), or poly(methyl acrylate) (PMAc), and crystalline side chains, poly(ethylene glycol) (PEG), have been prepared by copolymerization of PEG macromonomers with methyl methacrylate or methyl acrylate (MMAx or MACx, respectively). Because of the compatibility of PMMA/PEG and PMAc/PEG, from small-angle X-ray scattering results, the main and side chains in graft copolymers were suggested to be homogeneous in the molten state. Differential scanning calorimetry (DSC) cooling scans revealed that PEG side chains for graft copolymers with large PEG fractions were crystallized when the sample was cooled, with a cooling rate of 10°C/min. The spherulite pattern observed by a polarized optical microscope suggested the growth of PEG crystalline lamellae. Crystallization of PEG in MMAx was more restrained than in MACx. From these results, we have concluded that the crystallization behavior of the grafted side chains is strongly influenced by the glass transition of a homogeneously molten sample as well as dilution of the crystallizable chains. Domain spacings for isothermally crystallized graft copolymers were described by interdigitating chain packing in crystalline-amorphous lamellar structure.

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Crystallization and melting behaviour in block copolymers of poly(ethylene oxide) with amorphous components. The influence of compatibility

Unger¹,

Donth

1991

Acta Polymerica

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By means of DSC, connections between melt crystallization (TJ and melting temperatures (T,) ofblock copolymers have been studied as depending on the compatibility of the block copolymer components. As examples for a compatible and an incompatible system, the systems poly(ethy1ene oxide) (PEO, crystalline)-poly(methy1 methacrylate) (PMMA, amorphous) and PEO/poly(tert.-butyl methacrylate) (PTBMA, amorphous), respectively, were used. The compatibility of both systems is described. In block copolymers of compatible components, T, depends on the composition, but it is less than in comparable blends. Provided a sufficient crystallization time is available, T, is, in effect, only dependent on the PEO molecular weight. In block copolymers of incompatible components both T, and T, were strongly determined by molecular weights ofall blocks of both components and, connected with that, by PEO domain sizes. T, vs. T,,, diagrams are presented and discussed. Kristallisationsund Schmelzverhalten in Blockcopolymeren des Poly(ethy1enoxid)s mit amorphen Komponenten. Der EinjluJ der Ver traglichkeit Mittels DSC-Untersuchungen wurden ZusammenhHnge zwischen Kristallisations-(TJ und Schmelztemperaturen (T,) inBlockcopolymeren in Abhlngigkeit von der Vertrlglichkeit der Copolymerkomponenten fur die Kristallisation aus der Schmelze untersucht. Als Beispiel fur ein vertrlgliches System wurde Poly(ethy1enoxid) (PEO, kristal1in)-Poly(methy1methacrylat) (PMMA, amorph) ausgewlhlt ; das unvertrlgliche System ist PEO-Poly(tert.-butylmethacrylat) (PTBMA, amorph). Das Vertrlglichkeitsverhalten beider Systeme wird beschrieben. In Blockcopolymeren aus vertrlglichen Komponenten hiingt T, von der Zusammensetzung ab, jedoch ist T, geringer als in vergleichbaren Blends. Ausreichende Kristallisationszeit vorausgesetzt, hlngt T , im wesentlichen nur von der PEO-Blockmolmasse ab. In Blockcopolymeren aus unvertriglichen Komponenten werden sowohl T, als auch T, stark von den Blockmolmassen der Einzelkomponenten und den damit verbundenen PEO-Domlnengrokn bestimmt. Es werden T,-T,-Diagramme vorgestellt und diskutiert.

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Comparison of Poly(Ethylene Oxide) Melt Crystallization in Blend and Block Copolymer Systems with Poly (Methyl Methacrylate) and Poly (Tert-Butyl Methacrylate)

Cited by 9 publications

References 16 publications

Crystallization of tethered polyethylene in confined geometries

Crystallization of tethered polyethylene in confined geometries

Side‐chain crystallization behavior of graft copolymers consisting of amorphous main chain and crystalline side chains: Poly(methyl methacrylate)‐graft‐poly(ethylene glycol) and poly(methyl acrylate)‐graft‐poly(ethylene glycol)

Crystallization and melting behaviour in block copolymers of poly(ethylene oxide) with amorphous components. The influence of compatibility

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