scholarly journals Shear and Extensional Rheology of Linear and Branched Polybutylene Succinate Blends

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 652
Author(s):  
Violette Bourg ◽  
Rudy Valette ◽  
Nicolas Le Moigne ◽  
Patrick Ienny ◽  
Valérie Guillard ◽  
...  
Keyword(s):  
Extensional Flow ◽  
Size Exclusion ◽  
Molecular Architecture ◽  
Extensional Rheology ◽  
Small Amplitude Oscillatory Shear ◽  
Long Chain Branching ◽  
Uniaxial Elongation ◽  
Extensional Rheometry ◽  
Exclusion Chromatography ◽  
Polybutylene Succinate

The molecular architecture and rheological behavior of linear and branched polybutylene succinate blends have been investigated using size-exclusion chromatography, small-amplitude oscillatory shear and extensional rheometry, in view of their processing using cast and blown extrusion. Dynamic viscoelastic properties indicate that a higher branched polybutylene succinate amount in the blend increases the relaxation time due to an increased long-chain branching degree. Branched polybutylene succinate exhibits pronounced strain hardening under uniaxial elongation, which is known to improve processability. Under extensional flow, the 50/50 wt % blend exhibits the same behavior as linear polybutylene succinate.

Comments on the measurement of long chain branching by size exclusion chromatography

1985 ◽  
Vol 13 (1) ◽  
Author(s):  
V. Grinshpun ◽  
A. Rudin ◽  
D. Potter
Keyword(s):  
Size Exclusion Chromatography ◽  
Size Exclusion ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Exclusion Chromatography ◽  
Long Chain

Oligomeric assembly and interactions within the human RuvB-like RuvBL1 and RuvBL2 complexes

2010 ◽  
Vol 429 (1) ◽  
pp. 113-125 ◽  
Author(s):  
Andrew Niewiarowski ◽  
Alison S. Bradley ◽  
Jayesh Gor ◽  
Adam R. McKay ◽  
Stephen J. Perkins ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Structural Model ◽  
Analytical Ultracentrifugation ◽  
Protein Complexes ◽  
Adenine Nucleotides ◽  
Size Exclusion ◽  
Molecular Architecture ◽  
Essential Components ◽  
Exclusion Chromatography

The two closely related eukaryotic AAA+ proteins (ATPases associated with various cellular activities), RuvBL1 (RuvB-like 1) and RuvBL2, are essential components of large multi-protein complexes involved in diverse cellular processes. Although the molecular mechanisms of RuvBL1 and RuvBL2 function remain unknown, oligomerization is likely to be important for their function together or individually, and different oligomeric forms might underpin different functions. Several experimental approaches were used to investigate the molecular architecture of the RuvBL1–RuvBL2 complex and the role of the ATPase-insert domain (domain II) for its assembly and stability. Analytical ultracentrifugation showed that RuvBL1 and RuvBL2 were mainly monomeric and each monomer co-existed with small proportions of dimers, trimers and hexamers. Adenine nucleotides induced hexamerization of RuvBL2, but not RuvBL1. In contrast, the RuvBL1–RuvBL2 complexes contained single- and double-hexamers together with smaller forms. The role of domain II in complex assembly was examined by size-exclusion chromatography using deletion mutants of RuvBL1 and RuvBL2. Significantly, catalytically competent dodecameric RuvBL1–RuvBL2, complexes lacking domain II in one or both proteins could be assembled but the loss of domain II in RuvBL1 destabilized the dodecamer. The composition of the RuvBL1–RuvBL2 complex was analysed by MS. Several species of mixed RuvBL1/2 hexamers with different stoichiometries were seen in the spectra of the RuvBL1–RuvBL2 complex. A number of our results indicate that the architecture of the human RuvBL1–RuvBL2 complex does not fit the recent structural model of the yeast Rvb1–Rvb2 complex.

scholarly journals A Mechanically Weak Extracellular Membrane-Adjacent Domain Induces Dimerization of Protocadherin-15

2018 ◽  
Author(s):  
P. De-la-Torre ◽  
D. Choudhary ◽  
R. Araya-Secchi ◽  
Y. Narui ◽  
M. Sotomayor
Keyword(s):  
Protein Interactions ◽  
Analytical Ultracentrifugation ◽  
Size Exclusion ◽  
Molecular Architecture ◽  
Protein Protein Interactions ◽  
Tip Link ◽  
Exclusion Chromatography ◽  
Protocadherin 15 ◽  
Cadherin 23 ◽  
Dynamics Simulations

ABSTRACTThe cadherin superfamily of proteins is defined by the presence of extracellular cadherin (EC) repeats that engage in protein-protein interactions to mediate cell-cell adhesion, cell signaling, and mechanotransduction. The extracellular domains of non-classical cadherins often have a large number of EC repeats along with other subdomains of various folds. Protocadherin-15 (PCDH15), a protein component of the inner-ear tip link filament essential for mechanotransduction, has eleven EC repeats and a membrane adjacent domain (MAD12) of atypical fold. Here we report the crystal structure of a pig PCDH15 fragment including EC10, EC11, and MAD12 in a parallel dimeric arrangement. MAD12 has a unique molecular architecture and folds as a ferredoxin-like domain similar to that found in the nucleoporin protein Nup54. Analytical ultracentrifugation experiments along with size exclusion chromatography coupled to multi-angle laser light scattering and small-angle X-ray scattering corroborate the crystallographic dimer and show that MAD12 induces parallel dimerization of PCDH15 near its membrane insertion point. In addition, steered molecular dynamics simulations suggest that MAD12 is mechanically weak and may unfold before tip-link rupture. Sequence analyses and structural modeling predict the existence of similar domains in cadherin-23, protocadherin-24, and the “giant” FAT and CELSR cadherins, indicating that some of them may also exhibit MAD-induced parallel dimerization.

Long-chain branching indices from size-exclusion chromatography of polyethylenes

1986 ◽  
Vol 24 (5) ◽  
pp. 1171-1176 ◽  
Author(s):  
V. Grinshpun ◽  
A. Rudin ◽  
K. E. Russell ◽  
M. V. Scammell
Keyword(s):  
Size Exclusion Chromatography ◽  
Size Exclusion ◽  
Chain Branching ◽  
Long Chain Branching ◽  
Exclusion Chromatography ◽  
Long Chain

Influence of the Molar Mass Distribution on the Elongational Behaviour of Polymer Solutions in Capillary Breakup

2005 ◽  
Vol 15 (1) ◽  
pp. 28-37 ◽  
Author(s):  
J. P. Plog ◽  
W.-M. Kulicke ◽  
C. Clasen
Keyword(s):  
Mass Distribution ◽  
Molar Mass ◽  
Relaxation Times ◽  
Size Exclusion ◽  
Molar Mass Distribution ◽  
Mean Values ◽  
Capillary Breakup ◽  
Mass Distributions ◽  
Uniaxial Elongation ◽  
Exclusion Chromatography

AbstractCommercially available, blended methylhydroxyethyl celluloses with similar weight-average molar masses but varying molar mass distributions were characterized by different techniques like steady shear flow and uniaxial elongation in capillary breakup experiments. The determined relaxation times t were then correlated with the absolute molar mass distribution acquired via SEC/MALLS/DRI (combined methods of size-exclusion-chromatography, multi angle laser light scattering and differential refractometer). In order to describe the longest relaxation time of the polymers in uniaxial elongation via integral mean values of the molar mass distribution, defined blends of polystyrene standards with varying molar mass distributions were characterized. The obtained data was scaled via different moments of the molecular weight distribution and could be correlated with the results obtained for the methylhydroxyethyl celluloses.

scholarly journals Effects of particle stiffness on the extensional rheology of model rod-like nanoparticle suspensions

Soft Matter ◽  
2019 ◽  
Vol 15 (5) ◽  
pp. 833-841 ◽  
Author(s):  
Christian Lang ◽  
Jan Hendricks ◽  
Zhenkun Zhang ◽  
Naveen K. Reddy ◽  
Jonathan P. Rothstein ◽  
...  
Keyword(s):  
Rheological Behavior ◽  
Small Amplitude ◽  
Oscillatory Shear ◽  
Steady Shear ◽  
Extensional Rheology ◽  
Small Amplitude Oscillatory Shear ◽  
Capillary Breakup ◽  
Extensional Rheometry ◽  
Nanoparticle Suspensions ◽  
Linear And Nonlinear

The linear and nonlinear rheological behavior of two rod-like particle suspensions as a function of concentration is studied using small amplitude oscillatory shear, steady shear and capillary breakup extensional rheometry.

scholarly journals Molecular and Supramolecular Changes in Polybutylene Succinate (PBS) and Polybutylene Succinate Adipate (PBSA) Copolymer during Degradation in Various Environmental Conditions

2018 ◽  
Author(s):  
Michal Puchalski ◽  
Grzegorz Szparaga ◽  
Tadeusz Biela ◽  
Sławomir Sztajnowski ◽  
Agnieszka Gutowska ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Structural Changes ◽  
Physical And Mechanical Properties ◽  
Size Exclusion ◽  
X Ray Diffraction ◽  
Aliphatic Polyesters ◽  
Exclusion Chromatography ◽  
Polybutylene Succinate ◽  
Injection Molded ◽  
Multiangle Laser Light Scattering

In this paper, the influence of the various degradation conditions, on the molecular and supramolecular structure of polybutylene succinate (PBS) and polybutylene succinate adipate (PBSA) copolymer during degradation time is described. Experiment was carried out by the use injection molded samples and normalized conditions of biodegradation in soil, composting and artificial weathering. Materials were studied by using size-exclusion chromatography (SEC) coupled with multiangle laser light scattering (MALLS) detection and wide-angle X-ray diffraction (WAXD). Additionally, the physical and mechanical properties of the samples were determined. The performed experiments clearly show difference impact of selected degradation condition on the macroscopic, supramolecular and molecular parameters of studied aliphatic polyesters. The structural changes in PBS and PBSA explain the observed changes in the physical and mechanical properties of the obtained injection molded samples.

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