Mechanical Properties of Thin Glassy Polymer Films Filled with Spherical Polymer-Grafted Nanoparticles

Nano Letters ◽  
2012 ◽  
Vol 12 (8) ◽  
pp. 3909-3914 ◽  
Author(s):  
Damien Maillard ◽  
Sanat K. Kumar ◽  
Benjamin Fragneaud ◽  
Jeffrey W. Kysar ◽  
Atri Rungta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Glassy Polymer ◽  
Grafted Nanoparticles

scholarly journals Dewetting of Glassy Polymer Films

2002 ◽  
Vol 88 (23) ◽  
Author(s):  
Vijay Shenoy ◽  
Ashutosh Sharma
Keyword(s):  
Polymer Films ◽  
Glassy Polymer

Polylactide-based stent coatings: biodegradable polymeric coatings capable of maintaining sustained release of the thrombolytic enzyme streptokinase

2020 ◽  
Vol 92 (8) ◽  
pp. 1329-1340
Author(s):  
A. G. Kolmakov ◽  
A. S. Baikin ◽  
S. V. Gudkov ◽  
K. N. Belosludtsev ◽  
E. O. Nasakina ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
De Novo ◽  
Membrane Surface ◽  
Aqueous Media ◽  
Polymeric Coatings ◽  
Short Term ◽  
Thrombolytic Activity ◽  
Viable Cells ◽  
Nitinol Stents

AbstractThe paper describes synthesis and testing of novel biodegradable polylactide-based polymer membranes with desired mechanical properties, which are capable of sustained and directed release of biomacromolecules with high molecular weight (in particular, streptokinase; m.w. 47 kDa). Streptokinase is a pharmaceutical agent, possessing a pronounced thrombolytic activity. The membranes synthesized had a percentage elongation of 2–11% and tensile strength of 25–85 MPa. They were biodegradable – yet being stored in aqueous media in the absence of biological objects, would be dissolved by no more than 10% in 6 months. The synthesized membranes were capable of controlled release of streptokinase into the intercellular space, with the enzyme retaining more than 90% of its initial activity. The rate of streptokinase release from the membranes varied from 0.01 to 0.04 mg/day per cm2 of membrane surface. The membrane samples tested in the work did not have any short-term toxic effects on the cells growing de novo on the membrane surface. The mitotic index of those cells was approximately 1.5%, and the number of non-viable cells on the surface of the polymer films did not exceed 3–4% of their total amount. The implantation of the synthesized polymers – as both individual films and coatings of nitinol stents – was not accompanied by any postoperative complications. The subsequent histological examination revealed no abnormalities. Two months after the implantation of polymer films, only traces of polylactide were found in the implant-surrounding tissues. The implantation of stents coated with streptokinase-containing polymers resulted in the formation of a mature and thick connective-tissue capsules. Thus, the polylactide membranes synthesized and tested in this work are biodegradable, possess the necessary mechanical properties and are capable of sustained and directed release of streptokinase macromolecules.

Advantages of bulge testing and rupture mechanism of glassy polymer films

Polymer ◽  
2019 ◽  
Vol 179 ◽  
pp. 121632 ◽  
Author(s):  
Ken Kojio ◽  
Aya Fujimoto ◽  
Tomoko Kajiwara ◽  
Chigusa Nagano ◽  
Shiori Masuda ◽  
...  
Keyword(s):  
Polymer Films ◽  
Glassy Polymer ◽  
Bulge Testing ◽  
Rupture Mechanism

scholarly journals Tuning the Relaxation of Nanopatterned Polymer Films with Polymer-Grafted Nanoparticles: Observation of Entropy–Enthalpy Compensation

Nano Letters ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 7441-7447 ◽  
Author(s):  
Sonal Bhadauriya ◽  
Xiaoteng Wang ◽  
Praveen Pitliya ◽  
Jianan Zhang ◽  
Dharmaraj Raghavan ◽  
...  
Keyword(s):  
Polymer Films ◽  
Grafted Nanoparticles

scholarly journals Friction and Mechanical Properties of AFM-Scan-Induced Ripples in Polymer Films

2021 ◽  
Vol 7 ◽  
Author(s):  
Sebastian Friedrich ◽  
Brunero Cappella
Keyword(s):  
Mechanical Properties ◽  
Polymer Films ◽  
Mechanical Response ◽  
Butyl Methacrylate ◽  
Clear Correlation ◽  
Contact Mode ◽  
Cantilever Deflection ◽  
Atomic Force ◽  
Volume Measurements ◽  
Force Volume

When compliant samples such as polymer films are scanned with an atomic force microscope (AFM) in contact mode, a periodic ripple pattern can be induced on the sample. In the present paper, friction and mechanical properties of such ripple structures on films of polystyrene (PS) and poly-n-(butyl methacrylate) (PnBMA) are investigated. Force volume measurements allow a quantitative analysis of the elastic moduli with nanometer resolution, showing a contrast in mechanical response between bundles and troughs. Additionally, analysis of the lateral cantilever deflection when scanning on pre-machined ripples shows a clear correlation between friction and the sample topography. Those results support the theory of crack propagation and the formation of voids as a mechanism responsible for the formation of ripples. This paper also shows the limits of the presented measuring methods for soft, compliant, and small structures. Special care must be taken to ensure that the analysis is not affected by artefacts.

Effect of tensile deformations on gas transport in glassy polymer films

Polymer ◽  
1981 ◽  
Vol 22 (3) ◽  
pp. 299-304 ◽  
Author(s):  
Thor L. Smith ◽  
Randall E. Adam
Keyword(s):  
Polymer Films ◽  
Gas Transport ◽  
Glassy Polymer

Polyurea With Hybrid Polymer Grafted Nanoparticles: A Parametric Study

2012 ◽  
Author(s):  
Kristin Holzworth ◽  
Gregory Williams ◽  
Bedri Arman ◽  
Zhibin Guan ◽  
Gaurav Arya ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Computational Modeling ◽  
Chain Length ◽  
Polymer Chain ◽  
Parametric Study ◽  
Nano Particles ◽  
Core Material ◽  
Experimental Characterization ◽  
Hybrid Polymer ◽  
Grafted Nanoparticles

The basis of this research is to mitigate shock through material design. In this work, we seek to develop an understanding of parametric variations in polyurea-based nano-composite materials through experimental characterization and computational modeling. Blast-mitigating applications often utilize polyurea due to its excellent thermo-mechanical properties. Polyurea is a microphase-separated segmented block copolymer formed by the rapid reaction of an isocyanate component and an amine component. Block copolymers exhibit unique properties as a result of their phase-separated morphology, which restricts dissimilar block components to microscopic length scales. The soft segments form a continuous matrix reinforced by the hard segments that are randomly dispersed as microdomains. The physical properties of the separate phases influence the overall properties of the polyurea. While polyurea offers a useful starting point, control over crystallite size and morphology is limited. For compositing, the blending approach allows superb control of particle size, shape, and density; however, the hard/soft interface is typically weak for simple blends. Here, we overcome this issue by developing hybrid polymer grafted nanoparticles, which have adjustable exposed functionality to control both their spatial distribution and interface. These nano-particles have tethered polymer chains that can interact with their surrounding environment and provide a method to control well defined and enhanced nano-composites. This approach allows us to adjust a number of variables related to the hybrid polymer grafted nanoparticles including: core size and shape, core material, polymer chain length, polymer chain density, and monomer type. In this work, we embark on a parametric study focusing on the effect of silica nanoparticle size, polymer chain length, and polymer chain density. Preliminary results from experimental characterization and computational modeling indicate that the dynamic mechanical properties of the material can be significantly altered through such parametric modifications. These efforts are part of an ongoing initiative to develop elastomeric composites with optimally designed compositions and characteristics to manage blast-induced stress-wave energy.

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