Nano-Mechanical Properties of Modified Poly(Methyl Methacrylate) Films Studied by Atomic Force Microscopy

Abstract

Atomic force microscopy (AFM) has been used to study the effect of various photoinitiators doped into poly(methyl methacrylate) (PMMA) on the mechanical properties of PMMA films at the nanometer scale. Pure and modified PMMA films (containing four different photoinitiators) were exposed to a mercury vapor lamp in air atmosphere. Force-distance curves for hardness, Young modulus, and adhesion forces were obtained using different AFM modes (tapping or contact-mode) and different tips (diamond or silicon nitride). The results revealed that the added photoinitiators slightly changed the nanomechanical properties of PMMA as a result of alterations in the photochemical reactions and physical processes occurring in the studied systems. tert-Butyl peroxybenzoate had the most efficient effect on the measured parameters in UV-irradiated PMMA, whereas benzoyl peroxide was less active. The mechanism of the observed processes is discussed.

Effect of stabilizer type on the physicochemical properties of poly(acrylic acid)/silver nanocomposites for biomedical applications

“…The three-sided pyramid diamond cantilever with 60°apex angle (with spring constant of 859 N/m) has been used for adhesion measurements. The details of such analysis using AFM were described earlier [20,21]. The presented results are the average of 10-40 measurements.…”

“…The adhesion force (F a ) of poly(acrylic acid) or PAA/AgNPs nanocomposite was determined using Eq. 1, where k is a spring constant of the cantilever, and D is the height of the peak on the force-distance curve during the unloading process [20,29].…”

Thermogravimetric analysis of thermal stability of poly(methyl methacrylate) films modified with photoinitiators

“…These activators induced PMMA photodegradability [12,13], but changed the nanomechanical and surface properties of such modified polymer insignificantly [14,15].…”

Crosslinked blends of poly(lactic acid) and polyacrylates: AFM, DSC and XRD studies

“…These properties determine the polymer behavior in the processes of adhesion, adsorption, permeation, catalysis, friction, wetting, printing etc. Among various experimental techniques allowing the characterization of the surface properties, the significance of AFM systematically increases [8][9][10]. Nowadays, AFM plays a key role in microelectronics, nano-and biotechnologies.…”