Synthesis and Characterization of Polybutadiene and Poly(ethylene−1-butene) Combs

Fernyhough, Christine M.; Young, R. N.; Poché, Drew S.; deGroot, A. Willem; Bosscher, F.

doi:10.1021/ma010713h

Cited by 43 publications

(45 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…†, that seem to be identi®ed with the relaxation of arms (fast) and crossbar (slow) [50] (and see ®gure 36). Similar features have arisen in polybutadiene`pom-pom' architecture polymer melts (in which more than two arms are attached at each extremity of the molecular crossbar; see ®gure 47 and section 5.2.2 below) [87] and entangled combs [86,123,124].…”

Section: H-polymers and Combsmentioning

confidence: 55%

“…As an illustration of what may be achieved, we give in ®gure 8 a reaction scheme for the synthesis of comb topologies from PB [86]. More complex architectures have been proposed and investigated, including`pom-poms' [87] and arborescent polymers [88].…”

Section: Chemical Synthesis Of Controlled Topologiesmentioning

confidence: 99%

“…More complex monodisperse branched polymers such as H-shaped melts [50,122],`pom-poms' [87] and combs [86,123,124] have been manufactured anionically and measured by linear rheology. In these cases clusters of relaxation process appear, in some cases as if the melts were composed of bimodal blends of linear chains.…”

Section: T C B Mcleish 1404mentioning

confidence: 99%

See 2 more Smart Citations

Tube theory of entangled polymer dynamics

McLeish

2002

Advances in Physics

833

1,122

View full text Add to dashboard Cite

The dynamics of entangled¯exible polymers is dominated by physics general to many chemical systems. It is an appealing interdisciplinary ®eld where experimental and theoretical physics can work closely with chemistry and chemical engineering. The role of topological interactions is particularly important, and has given rise to a successful theoretical framework: the`tube model'. Progress over the last 30 years is reviewed in the light of specially-synthesized model materials, an increasing palette of experimental techniques, simulation and both linear and nonlinear rheological response. Our current understanding of a series of processes in entangled dynamics:`reptation',`contour length¯uctuation' and`constraintrelease' are set in the context of remaining serious challenges. Especial attention is paid to the phenomena associated with polymers of complex topology or`long chain branching'.

show abstract

Section: H-polymers and Combsmentioning

confidence: 55%

Section: Chemical Synthesis Of Controlled Topologiesmentioning

confidence: 99%

See 1 more Smart Citation

Tube theory of entangled polymer dynamics

McLeish

2002

Advances in Physics

833

1,122

View full text Add to dashboard Cite

show abstract

“…Star polymers with varying numbers of arms have been widely produced and studied [1][2][3][4][5][6][7][8] and branched polymers of increasing complexity and diverse structures have evolved. These include H-shaped polymers [9][10][11][12][13][14][15], comb-shaped polymers [16][17][18][19][20][21][22][23][24][25][26][27][28] and more recently dendritically branched polymers [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48]. Fundamental to all these studies is the ability of the synthetic polymer chemist to control structural homogeneity and produce branched ...…”

Section: Introductionmentioning

confidence: 99%

Synthesis and temperature gradient interaction chromatography of model asymmetric star polymers by the “macromonomer” approach

Agostini¹

2013

European Polymer Journal

View full text Add to dashboard Cite

. (2013) 'Synthesis and temperature gradient interaction chromatography of model asymmetric star polymers by the "macromonomer"approach.', European polymer journal., 49 (9). pp. 2769-2784. Further information on publisher's website:http://dx.doi.org/10.1016/j.eurpolymj.2013.06.021Publisher's copyright statement: NOTICE: this is the author's version of a work that was accepted for publication in European Polymer Journal. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be re ected in this document. Changes may have been made to this work since it was submitted for publication. A de nitive version was subsequently published in European Polymer Journal, 49, 9, 2013Journal, 49, 9, , 10.1016Journal, 49, 9, /j.eurpolymj.2013.021. Additional information:Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Abstract. We describe herein the synthesis and characterisation of a series of asymmetric three arm polystyrene stars via the "macromonomer" approach. The stars have been designed as model polymers to probe branched polymer dynamics and in particular to establish the chain-length of side-arm which precipitates a change in the rheological properties of the resulting polymers from "linear-like" to "star-like". Thus, a homologous series of three arm stars have been prepared in which the molar mass of two (long) arms are fixed at 90 000 gmol -1 and the molar mass of the remaining (short) arm is varied from below the entanglement molecular weight (M e ) to above M e . The arms were prepared by living anionic polymerisation, resulting in well-defined chain lengths with narrow molecular weight distribution. In contrast to the usual chlorosilane coupling approach, the macromonomer approach involves the introduction of reactive chain-end functionalities on each of the arms, either through the use of a functionalised (protected) initiator or a functional end-capping agent, which allows the stars to be constructed by a simple condensation coupling reaction. In this study we will compare the relative efficiency of a Williamson and 'click' coupling reaction in producing the stars. Most significantly, although this approach maybe a little more time-consuming than the more common silane coupling reaction, in the present study the "long" arm may be produced in sufficient quantity such that all of the asymmetric stars are produced with long arms of identical molecular weight -the only remaining variable being the molecular weight of th...

show abstract

“…A linear hydrogenated polybutadiene trimodal blend was prepared from low-polydisperse polymers 24 whose molecular weights are 1770, 1080, and 18 kDa (the latter is used as a matrix). The blend contains 2 wt % of 1770 kDa chains and 2 wt % of 1080 kDa chains in the matrix.…”

Section: Methodsmentioning

confidence: 99%

Using multimodal blends to elucidate the mechanism of flow‐induced crystallization in polymers

Okura

Chambon

Mykhaylyk

et al. 2011

J Polym Sci B Polym Phys

View full text Add to dashboard Cite

The effect of polydispersity on the formation of flow-induced, oriented morphology in polyolefins is investigated by polarized light imaging and small angle X-ray scattering. A torsional shear flow was applied at different temperatures to model polyethylene blends (bimodal and trimodal hydrogenated polybutadienes) comprising of two kinds of long chains with different molecular weight (1080 and 1770 kDa) in a matrix of short chains (18 KDa), and the results were compared to those of polydisperse materials. While a single boundary associated with the threshold flow conditions for the onset of oriented morphology is observed in the bimodal blends, two boundaries corresponding to the orientation of the longest chains (1770 kDa) and next longest chains (1080 kDa) are detected in the trimodal blends. The results obtained, herein, are extended by inference to polydisperse polymers. It is demonstrated that the shear rate dependence of the critical specific work parameter for the onset of oriented morphology in polydisperse polymers is dictated by the molecular weight distribution and that the longest chains mainly control the process with some contribution from shorter chains involved in the formation of flow-induced precursors at higher flow rates. KEYWORDS: crystallization; orientation; SAXS; viscoelastic properties INTRODUCTION Polyolefins are the most widely used polymer nowadays due to their excellent cost-benefit performance. The typical processing methods for semicrystalline polyolefins take a melt and shape it by means of either an extrusion or molding technique and the shape stabilization process is crystallization by cooling.1 The flow conditions in the extruder, and die or mold system have a profound effect on the morphology of the crystalline material and introduce different forms of crystals from isotropic spherulites to highly oriented ''shish-kebab structure'' in the polyolefin with the significant effect on materials through their mechanical, thermal, and optical properties.2 As processing conditions (temperature, pressure, flow rate, and duration of flow) can be adjusted and are relatively easy to control, the relationship between this group of parameters and characteristics of the polymer (chemical composition and molecular weight distribution) could significantly improve the control of structural morphologies and widen an understanding of flowinduced phenomena in polymeric materials.

show abstract

Synthesis and Characterization of Polybutadiene and Poly(ethylene−1-butene) Combs

Cited by 43 publications

References 49 publications

Tube theory of entangled polymer dynamics

Tube theory of entangled polymer dynamics

Synthesis and temperature gradient interaction chromatography of model asymmetric star polymers by the “macromonomer” approach

Using multimodal blends to elucidate the mechanism of flow‐induced crystallization in polymers

Contact Info

Product

Resources

About