Nanoindentation of Amorphous and Nanostructured Polymers

2003 ◽  
Vol 778 ◽  
Author(s):  
Kyle C. Maner ◽  
Matthew R. Begley ◽  
Marcel Utz
Keyword(s):  
Block Copolymer ◽  
Size Dependence ◽  
Shear Zones ◽  
Amorphous Polymers ◽  
Scale Dependence ◽  
Plastic Shear ◽  
Nanostructured Polymers ◽  
Elementary Processes ◽  
Lamellar Morphology ◽  
Poly Ethylene

AbstractWe present a detailed nanoindentation study of micron-scale thin films of polystyrene (PS), poly(phenylene oxide) (PPO), poly(methyl methacrylate) (PMMA), a metal-centered PMMA-Ruthenium block copolymer, and a PS-poly(ethylene-propylene) (PS-PEP) block copolymer with lamellar morphology. The results show that size-dependence is most readily noticeable for the lamellar PS-PEP film, indicating that the nanoidentation approach has sufficient sensitivity to capture scale dependence on scales in the range of tens of nanometers. The less pronounced scale-dependence (or lack thereof) in the other films is discussed in the context of identifying the physical length-scale of elementary processes of plastic deformation. The results indicate that the upper limit on the size of plastic shear zones in amorphous polymers is approximately 1200-9600 nm3 (i.e. a sphere with a diameter in the range of 20-40 nm).

Nanostructured Polymers Obtained from Polyethylene-block-poly(ethylene oxide) Block Copolymer in Unsaturated Polyester

2007 ◽  
Vol 40 (7) ◽  
pp. 2532-2538 ◽  
Author(s):  
Christophe Sinturel ◽  
Marylène Vayer ◽  
René Erre ◽  
Heinz Amenitsch
Keyword(s):  
Block Copolymer ◽  
Ethylene Oxide ◽  
Unsaturated Polyester ◽  
Nanostructured Polymers ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

Plastic Deformation of Glassy Polymers: Correlation Between Shear Activation Volume and Entanglement Density

2002 ◽  
Vol 734 ◽  
Author(s):  
Janet Ho ◽  
Leon Govaert ◽  
Marcel Utz
Keyword(s):  
Plastic Deformation ◽  
Plane Strain ◽  
Activation Volume ◽  
Shear Zones ◽  
Glassy Polymers ◽  
Strain Rates ◽  
Plastic Shear ◽  
Elementary Processes ◽  
Entanglement Density ◽  
Phenylene Oxide

ABSTRACTThe shear activation volumes of miscible polystyrene-poly(2,6-dimethyl-1,4-phenylene oxide) (PS-PPO) blends at different PS-PPO ratios were determined experimentally by both plane strain and uniaxial compression at constant strain rates. We find that the same correlation between the shear activation volume and the entanglement density ρe holds for the blend as well as for various pure glassy polymers: . Since the shear activation volume is closely related to the size of the plastic shear zones, this correlation suggests that the cooperativity of the elementary processes of plastic deformation in glassy polymers scales with the entanglement density.

Glucose-Responsive Hybrid Nanoassemblies in Aqueous Solutions: Ordered Phenylboronic Acid within Intermixed Poly(4-hydroxystyrene)-block-poly(ethylene oxide) Block Copolymer

2015 ◽  
Vol 16 (12) ◽  
pp. 3731-3739 ◽  
Author(s):  
Alicja Matuszewska ◽  
Mariusz Uchman ◽  
Agnieszka Adamczyk-Woźniak ◽  
Andrzej Sporzyński ◽  
Stergios Pispas ◽  
...  
Keyword(s):  
Block Copolymer ◽  
Ethylene Oxide ◽  
Aqueous Solutions ◽  
Phenylboronic Acid ◽  
Poly Ethylene Oxide ◽  
Poly Ethylene

A study on emulsion stabilization induced with linear and cyclized polystyrene-poly(ethylene oxide) block copolymer surfactants

2015 ◽  
Vol 47 (5) ◽  
pp. 408-412 ◽  
Author(s):  
Eisuke Baba ◽  
Toshiaki Yatsunami ◽  
Takuya Yamamoto ◽  
Yasuyuki Tezuka
Keyword(s):  
Block Copolymer ◽  
Ethylene Oxide ◽  
Poly Ethylene Oxide ◽  
Emulsion Stabilization ◽  
Poly Ethylene

scholarly journals Local Toxicity of Topically Administrated Thermoresponsive Systems: In Vitro Studies with In Vivo Correlation

2018 ◽  
Vol 47 (3) ◽  
pp. 426-432 ◽  
Author(s):  
Sivan Yogev ◽  
Ayelet Shabtay-Orbach ◽  
Abraham Nyska ◽  
Boaz Mizrahi
Keyword(s):  
Block Copolymer ◽  
Ethylene Glycol ◽  
Medical Devices ◽  
Poly Lactic Acid ◽  
Poly Ethylene Glycol ◽  
Thermoresponsive Polymers ◽  
Wide Range ◽  
Poly Ethylene

Thermoresponsive materials have the ability to respond to a small change in temperature—a property that makes them useful in a wide range of applications and medical devices. Although very promising, there is only little conclusive data about the cytotoxicity and tissue toxicity of these materials. This work studied the biocompatibility of three Food and Drug Administration approved thermoresponsive polymers: poly( N-isopropyl acrylamide), poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) tri-block copolymer, and poly(lactic acid-co-glycolic acid) and poly(ethylene glycol) tri-block copolymer. Fibroblast NIH 3T3 and HaCaT keratinocyte cells were used for the cytotoxicity testing and a mouse model for the in vivo evaluation. In vivo results generally showed similar trends as the results seen in vitro, with all tested materials presenting a satisfactory biocompatibility in vivo. pNIPAM, however, showed the highest toxicity both in vitro and in vivo, which was explained by the release of harmful monomers and impurities. More data focusing on the biocompatibility of novel thermoresponsive biomaterials will facilitate the use of existing and future medical devices.

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