Method for Structural Characterization of High Polymeric Networks by an Osmotic Pressure Technique

1968 ◽  
Vol 41 (2) ◽  
pp. 432-436
Author(s):  
R. D. Seeley ◽  
P. B. Rand
Keyword(s):  
Molecular Weight ◽  
Osmotic Pressure ◽  
Polymer Network ◽  
Polymeric Materials ◽  
Polymer Systems ◽  
Polymeric Networks ◽  
A Value ◽  
Solvent Systems ◽  
Solute Component

Abstract An apparatus was designed to measure the osmotic pressure of solvent-polymer systems. The method is unique in that semirigid polymers may be incorporated as the solute component without specimen fissures occurring from excessive solvent dilative action. The advantages of this technique are: high polymeric materials both elastomeric and plastic can be structurally characterized by the same technique; the calculated effective molecular weight of the polymer network will reflect a value consistent with the polymer's performance characteristics; and the method is only restricted to lyophilic polymer—solvent systems.

Characteristic Ratio and Plateau Modulus of 1,2-Polybutadiene. A Comparison with Other Rubbers

1990 ◽  
Vol 63 (5) ◽  
pp. 734-746 ◽  
Author(s):  
Jacques Roovers ◽  
Paul M. Toporowski
Keyword(s):  
Molecular Weight ◽  
Star Polymer ◽  
Dilute Solution ◽  
Plateau Modulus ◽  
Characteristic Ratio ◽  
Polymer Systems ◽  
Dilute Solution Properties ◽  
Linear Viscoelastic ◽  
Low Levels

Abstract In the course of work on linear and ring polybutadienes with 62% 1,2 units, a number of discrepancies were noted with data on polybutadienes of various microstructure available in the literature. For example, GNο=870 kPa for our 62% 1,2-polybutadiene. This is larger than GNο=730 kPa for a 56% 1,2-polybutadiene and GNο=550 kPa for a 78% 1,2-polybutadiene sample. The cis : trans ratio of our 62% 1,2-polybutadiene, prepared with potassium counterion, is 1 : 4, On the other hand, the cis : trans ratio of 62% 1,2-polybutadiene prepared with a modified Li catalyst is estimated to be 1 : 2. It is conceivable that the different cis : trans ratio leads to different properties at constant 1,2 content. Nevertheless, the low levels of both the cis and the trans units are not expected to cause more than minor differences in the properties of the polybutadienes. Correct values for GNο of model polymers are important for the study of the influence of the chemical structure on the melt characteristics of a polymer. For this reason, it was thought useful to reinvestigate 1,2-polybutadiene itself in some detail. The synthesis of narrow molecular-weight distribution 1,2-polybutadiene by anionic polymerization techniques has been described recently. The dilute-solution properties of 1,2-polybutadiene has been investigated. The melt rheology of two 1,2-polybutadiene samples have been studied, but no systematic study of the molecular-weight dependence of the melt properties was made. 1,2-Polybutadiene has been used as a component in block copolymers with 1,4-polybutadiene. These studies have permitted an investigation of the phase behavior of two rubbery blocks at room temperature. Poly(l,4-butadiene-graft-l,2-butadiene)s with well-defined composition and architecture have also been prepared. Hydrosilylated 1,2-polybutadiene has found use as the coupling agent for multiarm star polymer, and this method can easily be extended to the preparation of poly( l,2-butadiene-graft-l,4-butadiene). Hydrogenated 1,2-polybutadienes are prepared as model polymers for poly(l-butene). The synthesis and characterization of a series of 1,2-polybutadienes are described here. Special attention is given to low-molecular-weight polymers. The linear viscoelastic properties of the melts are also described. In the discussion, the relation between the characteristic ratio, C∞, and the plateau modulus, GNο, of a number of model polymer systems is explored.

Recent advances in “bioartificial polymeric materials” based nanovectors

2017 ◽  
Vol 2 (4) ◽  
Author(s):  
Raffaele Conte ◽  
Ilenia De Luca ◽  
Anna Valentino ◽  
Anna Di Salle ◽  
Anna Calarco ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Polymeric Material ◽  
Polymeric Materials ◽  
Polymer Chemistry ◽  
Loading Capacity ◽  
Polymer Therapeutics ◽  
Heterogeneous Architectures ◽  
Wide Range ◽  
Medical Interest

AbstractThis chapter analyzes the advantages of the use of bioartificial polymers as carriers and the main strategies used for their design. Despite the enormous progresses in this field, more studies are required for the fully evaluation of these nanovectors in complex organisms and for the characterization of the pharmacodynamic and pharmacokinetic of the loaded drugs. Moreover, progresses in polymer chemistry are introducing a wide range of functionalities in the bioartificial polymeric material (BPM) nanostructures leading to a second generation of bioartificial polymer therapeutics based on novel and heterogeneous architectures with higher molecular weight and predictable structures, in order to achieve greater multivalency and increased loading capacity. Therefore, research on bioartificial polymeric nanovectors is an “on-going” field capable of attracting medical interest.

Characterization of Polymers and Their Surfaces Using Ultra-Soft X-Ray Absorption Spectroscopy

1993 ◽  
Vol 304 ◽  
Author(s):  
Gary E. Mitchell ◽  
Benjamin M. Dekoven ◽  
David R. Speth ◽  
Mark E. Jones ◽  
James J. Curphy ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Film Thickness ◽  
Absorption Spectroscopy ◽  
Film Surface ◽  
Polymeric Materials ◽  
Fluorescence Yield ◽  
X Ray ◽  
Surface Sensitivity ◽  
X Ray Absorption

AbstractIn this paper we illustrate the use of Ultra Soft X-ray Absorption Spectroscopy (USXAS) for the characterization of polymeric materials by highlighting three novel applications of the technique. The surface sensitivity of electron yield (3 nm) and the bulk information available from fluorescence yield USXAS (200 nm) provide unique information on the chemistry of polymer surfaces and interfaces. USXAS is sensitive to both concentration and orientation of functional groups in polymers. The systems highlighted here include the characterization of flame treated model acrylic automotive coatings, ultra-low surface energy crosslinked fluorocarbon films, and spin cast polystyrene films. The chemical and surface sensitivity of the technique are emphasized by the ability of USXAS to detect an increase in the trigonally coordinated carbon at the surface after treatment with a reducing flame. The sensitivity to functional group orientation at the surface is demonstrated by the characterization of the crosslinked flurocarbon polymer films. The results show that the pendant fluoroalkyl moieties of these polymers are strongly oriented perpendicular to the film surface. Spin coated polystyrene films were characterized as a functionv of molecular weight, film thickness and casting solvent. The pendant phenyl groups were found to be preferentially oriented towards the normal to the surface plane, independent of casting solvent, molecular weight, and film thickness

Preparation and characterization of the double acetates of zinc, cadmium and mercury(II)

1976 ◽  
Vol 29 (3) ◽  
pp. 573 ◽  
Author(s):  
KC Malhotra ◽  
DS Katoch
Keyword(s):  
Molecular Weight ◽  
Acetic Anhydride ◽  
Alkali Metals ◽  
A Value ◽  
Zinc Cadmium

Double acetates of composition M2[M(OAC)4]3xAc2O, where x may have a value of four or six, have been isolated from acetic anhydride by mixing the anhydrous acetates of zinc, cadmium and mercury and the acetates of alkali metals, ammonium and thallium in acetic anhydride. From the conductance, molecular weight, 1.r. and t.g.a. studies, their structures have been elucidated.

The Application of Atomic Force Microscopy to the Characterization of Industrial Polymer Materials

MRS Bulletin ◽  
2004 ◽  
Vol 29 (7) ◽  
pp. 464-470 ◽  
Author(s):  
Georg K. Bar ◽  
Gregory F. Meyers
Keyword(s):  
Atomic Force Microscopy ◽  
Polymeric Materials ◽  
Porous Polymer ◽  
Polymer Materials ◽  
Phase Imaging ◽  
Structure Property ◽  
Polymer Systems ◽  
Force Microscopy ◽  
Atomic Force

AbstractAtomic force microscopy (AFM) is now well established among the tools of choice for the analysis and characterization of materials.Applications of AFM span many industries including chemicals, plastics, pharmaceuticals, and semiconductors.Advancements in AFM instrumentation over the last five years have expanded the range of application of this technology to investigate thermal and mechanical properties of complex materials at high spatial resolution as well as structural and morphological characterization of materials subjected to thermal and mechanical stresses.In particular, this has been an enabling technology for an improved understanding of structure–property relationships in polymeric materials including homopolymers, blends, impact-modified polymer systems, porous polymer systems, and semicrystalline polymers.Practical examples illustrate applications of contact, tapping-mode, phase-imaging, hot-stage, and scanning thermal methods for the characterization of modern industrial polymer materials.

scholarly journals Preparation and characterization of double macromolecular network (DMMN) hydrogels based on hyaluronan and high molecular weight poly(ethylene glycol)

2015 ◽  
Vol 3 (32) ◽  
pp. 6618-6625 ◽  
Author(s):  
Changjiang Fan ◽  
Chao Zhang ◽  
Liqiong Liao ◽  
Sheng Li ◽  
Weiping Gan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ethylene Glycol ◽  
Network Structure ◽  
Polymer Network ◽  
Poly Ethylene Glycol ◽  
Double Network ◽  
Macromolecular Network ◽  
Poly Ethylene ◽  
High Molecular Weight Poly

Ultra-strong and resilient double macromolecular network (DMMN) hydrogels with a more evenly distributed polymer network and a double-network structure have been developed.

Distinguishing relaxation dynamics in transiently crosslinked polymeric networks

2017 ◽  
Vol 8 (35) ◽  
pp. 5336-5343 ◽  
Author(s):  
Cindy Soo Yun Tan ◽  
Gillie Agmon ◽  
Ji Liu ◽  
Dominique Hoogland ◽  
Emma-Rose Janeček ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Mechanical Behaviour ◽  
Polymeric Materials ◽  
Relaxation Dynamics ◽  
Polymer Molecular Weight ◽  
Polymeric Networks ◽  
And Control

Polymeric materials based on reversible non-covalent associations possess diverse mechanical behaviour, which can be orthogonally accessed through polymer molecular weight and control over physical crosslinks.

scholarly journals Facile fabrication of polymer network using click chemistry and their computational study

2021 ◽  
Vol 8 (3) ◽  
pp. 202056
Author(s):  
Md. Kausar Ahmed ◽  
Ajoy Kumer ◽  
Abu Bin Imran
Keyword(s):  
Click Reaction ◽  
Computational Study ◽  
Polymer Network ◽  
Cycloaddition Reaction ◽  
Polymeric Materials ◽  
High Yield ◽  
H Nmr ◽  
Facile Fabrication ◽  
Derivatives Of

Click reaction is a very fast, high yield with no by-product, biocompatible, tolerant to surrounded medium, and very specific cycloaddition reaction between azides and alkynes to form triazole. They are widely being employed in the synthesis of various polymeric materials. Here, the design, fabrication and characterization of hydrogel prepared using click reaction have been reported. At first, telechelic acetylene precursor for click reaction is prepared from diisocyanatohexane and propargyl alcohol in the presence of triethylamine. The azide derivatives of poly(hydroxyethylmethacrylate), i.e. poly(HEMA), are successfully prepared following two different routes. In route 1, esterification of bromopropionic acid is performed with HEMA monomer using N,N′- dicyclohexylcarbodiimide/4-dimethylaminopyridine (DCC/DMAP) as a catalyst followed by replacing bromide by azide moiety. Free radical polymerization of the fabricated monomer is then performed under N 2 atmosphere using azobisisobutyronitrile (AIBN) as an initiator. In route 2, polymerization of HEMA has been carried out first, then modification of the polymer with azide group via successive steps to obtain azide derivative polymer for click reaction. The hydrogel is prepared by a very fast, highly specific, and simple click reaction between azide derivative polymer and telechelic acetylene precursor using copper as a catalyst. The structures of derivatives of azide-functionalized HEMA, acetylene precursors and hydrogels are confirmed by FTIR and 1 H-NMR spectroscopy. The optimized structure of each precursor is determined, and their chemical and thermodynamic parameters are computationally studied in detail.

The Influence of Relaxation Effects on the Physical Properties of Polymeric Materials

2018 ◽  
Vol 45 (5) ◽  
pp. 191-195
Author(s):  
V.M. Aristov ◽  
E.P. Aristova
Keyword(s):  
Molecular Weight ◽  
Physical Properties ◽  
High Molecular Weight ◽  
Polymeric Materials ◽  
Relaxation Processes ◽  
Polymer Systems ◽  
Relaxation Properties ◽  
Relaxation Effects

The nature of the physical properties of polymeric materials is considered. Data on relaxation processes in high-molecular-weight compounds are given. The dependence of mechanical losses on the structure of polymer systems is shown. The modification of polymers as manifested by a change in their relaxation properties is investigated.

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