Block and Graft Copolymers of Pivalolactone. 4. Triblock and Block-Graft Copolymers from Pivalolactone and Isoprene

Foss, R. P.; Jacobson, H. W.; Cripps, H. N.; Sharkey, W. H.

doi:10.1021/ma60072a039

Cited by 18 publications

(10 citation statements)

References 2 publications

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“…Inspection of the DSC curve of the PEO-4K sample complexed with NaSCN shows the presence of a second but smaller endotherm at 331 K. The latter appears at a temperature that is only 2 K lower than the melting endotherm observed for the uncomplexed PEO-4K sample. This indicates that the molar ratio of the PEO monomer units to NaSCN of 4 chosen for the present study does not correspond to the exact stoichiometry of the PEO-NaSCN complex. This was confirmed by wide-angle X-ray diffraction measurements, which showed the PEO reflexions in addition to those of the complexed new crystalline entity.…”

Section: Resultsmentioning

confidence: 92%

Thermal and mechanical properties of a poly(ethylene oxide-b-isoprene-b-ethylene oxide) block polymer complexed with sodium thiocyanate

Robitaille¹,

Prud’homme²

1983

Macromolecules

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The changes in thermal and mechanical properties produced by complexation with NaSCN of a polyethylene oxide-b-isoprene-b-ethylene oxide) (PEO-PI-PEO) block polymer are described. The number-average molecular weight of the PEO-PI-PEO polymer was 1.67 X 105, and its PEO weight fraction was 0.14. It is shown that complexation, which occurs selectively with the PEO end blocks, can yield a semicrystalline thermoplastic elastomer that melts at about 450 K. The main characteristics of the complexed block polymer are a crystallization temperature, which occurs 90 K lower than that of complexed homo-PEO, and good dimensional stability at high temperature. However, the tensile strength of the complexed material appears to be considerably reduced with increasing temperature. A pronounced supercooling was also observed for the uncomplexed PEO-PI-PEO block polymer. This phenomenon seems to be a general feature of two-phase block polymers in which the crystallizable component is finely dispersed into isolated microdomains.

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Section: Resultsmentioning

confidence: 92%

Thermal and mechanical properties of a poly(ethylene oxide-b-isoprene-b-ethylene oxide) block polymer complexed with sodium thiocyanate

Robitaille¹,

Prud’homme²

1983

Macromolecules

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“…Assuming a planar zigzag structure, a chain packing of the poly(ether ester)s may be presented as shown in Figure 3a. The melting behavior of the poly(ether ester)s might therefore be described using the following equation, 28 VTm -1/Tm°= ~(R/AHU) In p (2) in which Tm is the melting temperature of the copolymer, Tm°i s the melting temperature of the crystallizable homopolymer, R is the gas constant and AHn is the enthalpy of fusion per repeating unit; p is defined as the sequence propagation probability. For a random copolymer p equals the mole fraction of crystalline units Xa,28 thus converting eq 2 into 1/Tm -1/Tm°= -(R/ AHU) In Xa (3) As was shown in our previous paper,13 the amount of 3GT units could be determined directly from the 1H NMR spectra of the poly (ether ester)s. Plotting 1/Tm versus -In Xa yielded a linear relation for the copolymers (Figure 5).…”

Section: Resultsmentioning

confidence: 99%

Poly(ether esters) from pivalolactone, alkanediols, and dimethyl terephthalate. 2. Synthesis and characterization

Tijsma¹,

Does²,

Bantjes³

et al. 1994

Macromolecules

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Thermal properties of poly(ether ester)s prepared from pivalolactone (PVL), a homologous series of alkanediols (nG), and dimethyl terephthalate via a two-stage melt process were studied. Both the melting and crystallization temperatures of the poly(ether ester)s decreased with increasing length of the alkanediol used. An odd/even effect was observed, which was explained by assuming a planar zigzag structure. Furthermore, it was shown that the structure of the poly(ether ester)s could be described as consisting of crystalline alkylene terephthalate sequences, responsible for the melting behavior, and amorphous nG-PVL units. A Mark-Houwink equation was determined from viscometric data and from the molecular weights of the poly(ether ester)s. It was found that copolymers with molecular weights M" > 10 000 can be prepared by performing the polycondensation step at 275°C for 2.5 h or by applying a postcondensation. Furthermore, upscaling of the process could be carried out from 25 to 1000 g. The poly(ether ester)s were thermally stable up to 280°C and showed a melting behavior dependent upon the alkylene terephthalate block length.

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“…Usually, TPEEs contain two segments. One is the semi-crystalline polyester hard segment with a high melting temperature and excellent crystallization ability, and the other one is the amorphous polyether soft segment with a low glass transition temperature. − The crystallization of semi-crystalline polyester induces a microphase separation of the hard segment with the soft one. The microphase separation results in the rigid hard segment serving as a physical cross-link, and the flexible soft part acts as a reversible network.…”

Section: Introductionmentioning

confidence: 99%

Poly(neopentyl glycol 2,5-furandicarboxylate): A Promising Hard Segment for the Development of Bio-based Thermoplastic Poly(ether-ester) Elastomer with High Performance

Chi

Liu

et al. 2018

ACS Sustainable Chem. Eng.

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With a high melting temperature and good crystallization ability, poly(neopentyl glycol 2,5-furandicarboxylate) (PNF), a polyester derived from bio-based 2,5-furandicarboxylic acid and neopentyl glycol, has been proposed and proved to be a promising hard segment for the development of novel bio-based thermoplastic poly(ether-ester) elastomer (TPEE). The resulting TPEE, namely PNF–PTMG, has high performance comparable to the petroleum-based counterpart PBT–PTMG (i.e., Hytrel, Dupont). Among all of the existing polyesters derived from bio-based 2,5-furandicarboxylic acid (FDCA), PNF has perfectly balanced properties, namely, a high melting temperature of 200 °C and a good crystallization ability to easily grow medium to large-size crystalline spherulites. Characterizations based on dynamic mechanical analysis and small-angle X-ray scattering suggest that there are two domains in PNF–PTMG, the crystalline PNF and a mixture of amorphous PNF and PTMG. These two domains form microphase separation induced mainly by the crystallization of PNF. By adjusting the PTMG soft segment from 30 to 60 wt%, PNF–PTMG shows a melting temperature, tensile modulus (E), and elongation at the break (εb) ranging from 180 to 134 °C, 738 to 56 MPa, and 38 to 1089%, respectively. More importantly, the shape recovery ratios increase from 57 to 90% at 200% strain when the amount of PTMG increases from 50 to 70 wt%, indicating excellent elastic property. These results indicate that PNF is an excellent hard segment to serve as a strong physical cross-link so that PNF–PTMG is able to display high performance comparable to extensively commercialized PBT–PTMG.

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Block and Graft Copolymers of Pivalolactone. 4. Triblock and Block-Graft Copolymers from Pivalolactone and Isoprene

Cited by 18 publications

References 2 publications

Thermal and mechanical properties of a poly(ethylene oxide-b-isoprene-b-ethylene oxide) block polymer complexed with sodium thiocyanate

Thermal and mechanical properties of a poly(ethylene oxide-b-isoprene-b-ethylene oxide) block polymer complexed with sodium thiocyanate

Poly(ether esters) from pivalolactone, alkanediols, and dimethyl terephthalate. 2. Synthesis and characterization

Poly(neopentyl glycol 2,5-furandicarboxylate): A Promising Hard Segment for the Development of Bio-based Thermoplastic Poly(ether-ester) Elastomer with High Performance

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