Determination of Thermomechanical Properties of a Model Polymer Blend

Cappella, Brunero; Kaliappan, Senthil Kumar

doi:10.1021/ma061896g

Cited by 23 publications

(19 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The elastic moduli of PnBMA and PS measured in this experiment are larger than 1 GPa and 3 GPa, i.e., the values previously found by Cappella et al for bulk polymers [17,18,20], but are in agreement with the measured values of thin films of PnBMA [19,37,38]. Such larger Young's moduli are comprehensible, when the sample preparation and the constraints of the polymers are accounted for.…”

Section: Resultssupporting

confidence: 91%

See 1 more Smart Citation

Mechanical Properties and Adhesion of a Micro Structured Polymer Blend

Cappella

2011

Polymers

Self Cite

View full text Add to dashboard Cite

Abstract:A 50:50 blend of polystyrene (PS) and poly(n-butyl methacrylate) (PnBMA) has been characterized with an Atomic Force Microscope (AFM) in Tapping Mode and with force-distance curves. The polymer solution has been spin-coated on a glass slide. PnBMA builds a uniform film on the glass substrate with a thickness of ≅200 nm. On top of it, the PS builds an approximately 100 nm thick film. The PS-film undergoes dewetting, leading to the formation of holes surrounded by about 2 µm large rims. In those regions of the sample, where the distance between the holes is larger than about 4 µm, light depressions in the PS film can be observed. Topography, dissipated energy, adhesion, stiffness and elastic modulus have been measured on these three regions (PnBMA, PS in the rims and PS in the depressions). The two polymers can be distinguished in all images, since PnBMA has a higher adhesion and a smaller stiffness than PS, and hence a higher dissipated energy. Moreover, the polystyrene in the depressions shows a very high adhesion (approximately as high as PnBMA) and its stiffness is intermediate between that of PnBMA and that of PS in the rims. This is attributed to higher mobility of the PS chains in the depressions, which are precursors of new holes.

show abstract

Section: Resultssupporting

confidence: 91%

“…The mechanical behavior of PnBMA, both in bulk [17,18] and as thin or ultrathin films [19], and of PS [18,20] is well known and was examined in detail by means of force-displacement curves in our previous experiments.…”

Section: Methodsmentioning

confidence: 99%

Mechanical Properties and Adhesion of a Micro Structured Polymer Blend

Cappella

2011

Polymers

Self Cite

View full text Add to dashboard Cite

show abstract

“…Nanopillars present low elastic value and it can be explained in terms of thermosensitive behavior of the polymer. According to the literature, this polymer is especially sensitive to temperature, being room temperature a key point at which the elastic-plastic properties of the polymer change abruptly [ 42 , 55 , 56 , 57 , 58 ]. In fact, as previously observed by us and reported in literature, the Tg lies within the range of 20–30 °C, so that at room temperature, the polymer is just in the transition interval to a soft material.…”

Section: Resultsmentioning

confidence: 99%

In Situ Synthesis of Poly(butyl methacrylate) in Anodic Aluminum Oxide Nanoreactors by Radical Polymerization: A Comparative Kinetics Analysis by Differential Scanning Calorimetry and 1H-NMR

2021

View full text Add to dashboard Cite

In this work, we explore the ability to generate well-defined poly(butyl methacrylate) (PBMA) nanostructures by “in situ” polymerization of butyl methacrylate monomer (BMA). PBMA nanostructures of high and low aspect ratios have been successfully obtained through the free radical polymerization (FRP) of a BMA monomer in anodic aluminum oxide (AAO) nanoreactors of suitable size. A polymerization kinetics process has been followed by differential scanning calorimetry (DSC) and proton Nuclear Magnetic Resonance spectroscopy (1H-NMR).The determination of the kinetics of polymerization through DSC is based on a quick and direct analysis of the exothermic polymerization process, whereas the analysis through 1H-NMR also allows the unambiguous chemical analysis of the resulting polymer. When compared to bulk polymerization, both techniques demonstrate confinement effects. Moreover, DSC and 1H-NMR analysis give the same kinetics results and show a gel-effect in all the cases. The number average molecular weight (Mn) of the PBMA obtained in AAO of 60–300 nm are between 30·103–175·103 g/mol. Even if the Mn value is lower with respect to that obtained in bulk polymerization, it is high enough to maintain the polymer properties. As determined by SEM morphological characterization, once extracted from the AAO nanoreactor, the polymer nanostructures show controlled homogeneous aspect/size all throughout the length of nanopillar over a surface area of few cm2. The Young’s modulus of low aspect ratio PBMA nanopillars determined by AFM gives a value of 3.1 ± 1.1 MPa. In this work, a 100% of PBMA polymer nanostructures are obtained from a BMA monomer in AAO templates through a quick double process: 30 min of monomer immersion at room temperature and 90 min of polymerization reaction at 60 °C. While the same nanostructures are obtained by polymer infiltration of PBMA at 200 °C in about 6 h, polymerization conditions are much softer than those corresponding to the polymer infiltration process. Furthermore, the 1H-NMR technique has been consolidated as a tool for studying the kinetics of the copolymerization reactions in confinement and the determination of monomer reactivity ratios.

show abstract

“…Third, the elastic modulus E s , calculated from the linear fit of the sample deformation D 3/2 as a function of the cantilever deflection δ c . It is assumed that sample and tip are respectively a plane and a hemisphere or a paraboloid and that sample deformation is described by Hertz theory (Bonaccurso et al, 2006;Cappella and Kaliappan, 2006;Silbernagl and Cappella, 2010;Cappella, 2011;Cappella, 2016):…”

Section: Methodsmentioning

confidence: 99%

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

Friedrich

Cappella

2021

Front. Mech. Eng.

Self Cite

View full text Add to dashboard Cite

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.

show abstract

Determination of Thermomechanical Properties of a Model Polymer Blend

Cited by 23 publications

References 37 publications

Mechanical Properties and Adhesion of a Micro Structured Polymer Blend

Mechanical Properties and Adhesion of a Micro Structured Polymer Blend

In Situ Synthesis of Poly(butyl methacrylate) in Anodic Aluminum Oxide Nanoreactors by Radical Polymerization: A Comparative Kinetics Analysis by Differential Scanning Calorimetry and 1H-NMR

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

Contact Info

Product

Resources

About