Rheological Features of a Novel Poly(spiro phosphazene)

Carriedo, Gabino A.; Gómez‐Elipe, Paloma; Alonso, Francisco; Lizaso, Eli; Muñoz, Manuel López; Santamaría, Antonia

doi:10.1002/1521-3935(20011101)202:17<3437::aid-macp3437>3.0.co;2-h

Cited by 8 publications

(8 citation statements)

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“…On the contrary, for higher rubber contents (20, 30, and 40%) the curves obtained at each temperature are clearly dispersed, do not overlap onto a master one, and consequently, they cannot be empirically superposed. This case is indicative of relaxation times (or moduli) having nonuniform temperature dependence, which is characteristic of certain multiphase systems. , It is well-known that anisotropic or biphasic materials do not hold the time temperature superposition principle . In this sense, it is clear that the nonhomogeneity of a modified bitumen becomes more pronounced as rubber concentration increases, resulting in increasing deviations of the thermorheological simplicity.…”

Section: Resultsmentioning

confidence: 99%

Influence of Crumb Rubber Concentration on the Rheological Behavior of a Crumb Rubber Modified Bitumen

et al. 2005

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Bitumen is widely used in construction. Its applications go from binder for road asphalts to built-up roofing membranes and other waterproofing uses. The use of crumb tire rubber as a binder modifier may contribute to solving a waste disposal problem and to improving the quality of road pavements. This paper deals with the effect that rubber concentration exerts on the thermorheological properties of rubber-modified bitumens. The results obtained confirm that the rheology and storage stability of these modified binders are largely dependent on rubber concentration. The linear viscoelastic measurements carried out revealed an improvement of both low and high in-service properties of the binder. The viscous flow measurements showed an important increase in viscosity and a noticeable reduction in temperature susceptibility. A swelling process of the crumb rubber by light components of the maltenic fraction was confirmed by modulated differential scanning calorimetry (MDSC). The stability tests, performed on samples stored at 180°C, demonstrated that the storage stability of rubber-modified bitumen was improved as rubber concentration increased.

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Section: Resultsmentioning

confidence: 99%

Influence of Crumb Rubber Concentration on the Rheological Behavior of a Crumb Rubber Modified Bitumen

et al. 2005

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“…non‐spherical aggregates) . Our group investigated the self‐assembly of the rod‐ b ‐coil BCPs [N=P(O 2 C 12 H 8 )] n ‐ b ‐[N=PMePh] m { n = 50, m = 35 ( P Rig 1 ); n = 245, m = 60 ( P Rig 2 ); n = 20, m = 70 ( P Rig 3 ), see Scheme }, combining amorphous and flexible [N=PMePh] m segments with [N=P(O 2 C 12 H 8 )] n blocks which, having an activation energy at the glass transition ( T g ≈ 130 °C) of Δ H T g = 500 kJ mol –1 , are very rigid . From THF those polymers spontaneously originated well‐defined nano‐porous films by a vesicle‐to‐pore morphological evolution during the solvent evaporation (see Figure ) .…”

Section: Self‐assembly Of Linear Polyphosphazene Diblock Copolymersmentioning

confidence: 99%

Polyphosphazenes – Synthetically Versatile Block Copolymers (“Multi‐Tool”) for Self‐Assembly

2018

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This microreview outlines recent advances on the synthesis and self-assembly of polyphosphazene diblock copolymers, a class of versatile polymers (Multi-Tool) able to generate a great variety of different well-defined nanomorphologies. Particular focus is placed on the synthesis of linear block copolymers composed of two polyphosphazene chains (PP-b-PP′), or hybrid polymers combining one PP chain with a non- [a] 2484 Gabino A. Carriedo (Ph D in 1981) is Full-time Professor of Inorganic Chemistry in the University of Oviedo since 1989. His research interest in synthetic chemistry has included coordination and organometallic chemistry, electrochemistry and polymer chemistry. Since 1995 he has focused in designed syntheses of phosphazene polymers and their chemical derivatization. (2012) developing new synthetic methodologies in organic chemistry by means of organometallic carbene reagents under the supervision of Prof. J. Barluenga and Prof. J. Flórez. After, she moved to the group of D. Dixon (Oxford) to explore new catalytic asymmetric methodologies. She returned to the University of Oviedo in 2015 as Post-doctoral research assistant. Nowadays, her research is focused on the synthesis and self-assembly of new material based on polyphosphazene polymers. 2488 Scheme 4. Synthesis of linear polyphosphazene diblock copolymers 28-35 by sequential living cationic polymerization of phosphoranimines of type (X)(R 1 )(R 2 )P=N-SiMe 3 over living chains of 1[PCl 6 ]. Scheme 5. Sequential living polymerization of phosphoranimine 36 by using active end-groups of polyphosphazene 17 as initiators. The synthesis of BCP 37 is suggested in ref. 47. methodologies afforded the PP-b-PS copolymers with moderately good yields (< 60 %) and polydispersities (< 1.3). Scheme 10. Synthetic routes to polyphosphazene-b-polystyrene, PP-b-PS, via macromolecular coupling of telechelic (PS) n -P(R) 2 = N-SiMe 3 , 53 and 54, with an end-capped poly(dichlorophosphazene) 55 (Ec. c). Raquel de la Campa was born in Cangas del Narcea (Asturias, Spain) in 1981. He obtained his PhD at the University of OviedoRecently, our group developed a very convenient synthesis for linear hybrid PP-b-PS block copolymers (Scheme 11). [63] Using the lithiated-phosphine 56 as initiator, the anionic polymerization of styrene gave the telechelic polystyrene 57 (PS m -PPh 2 ) after quenching the reaction with Cl-SiMe 3 . The chlorination of Scheme 11. Synthetic routes to polyphosphazene-b-polystyrene, PP-b-PS (60), via lithiated-phosphine initiator 56, and macromolecular initiator 58.2492 57 led to PS m -PPh 2 Cl 2 (58) having -PPh 2 Cl 2 end-groups that initiate the polymerization of Cl 3 P=N-SiMe 3 (6) producing the block copolymer [N=PCl 2 ] n -PS m (59). The macromolecular substitution of the chlorine atoms by -OCH 2 CF 3 groups yielded the block copolymer [N=P(OCH 2 CF 3 ) 2 ] n -PS m (60) having crystalline PP blocks. This synthetic methodology afforded the hybrid PP-b-PS block copolymer in 70 % yield and with narrower polydispersities (PDI = 1.2) than those of the...

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“…52 Detailed rheological studies have been carried out on the interesting polymer poly(2,2Јdioxybiphenylphosphazene). 53 A size exclusion chromatography multi-angle laser light scattering study of poly(bis(piperidino)phosphazene) revealed that anomalous solution behaviour can be attributed to the coexistence of molecularly dispersed polymers and aggregates. 54 Short poly(phenylene vinylene) chains were grafted onto poly(bis(4-methylphenoxy)phosphazene) and the copolymer was found to exhibit blue photoluminescence.…”

Section: Group 15 Element-containing Polymers: Polyphosphazenes and O...mentioning

confidence: 99%

24 Inorganic and organometallic polymers

Gates

2002

Annu. Rep. Prog. Chem., Sect. A: Inorg. Chem.

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Rheological Features of a Novel Poly(spiro phosphazene)

Cited by 8 publications

References 25 publications

Influence of Crumb Rubber Concentration on the Rheological Behavior of a Crumb Rubber Modified Bitumen

Influence of Crumb Rubber Concentration on the Rheological Behavior of a Crumb Rubber Modified Bitumen

Polyphosphazenes – Synthetically Versatile Block Copolymers (“Multi‐Tool”) for Self‐Assembly

24 Inorganic and organometallic polymers

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