Thermomechanical and fractographic behavior of poly (HDDA‐co‐MMA): a study for its application in microcantilever sensors

Abstract

Polymer-based materials have drawn significant attention lately for their application in design and fabrication of thermomechanically stable highly sensitive three-dimensional (3D) micromechanical sensor structures. Among these materials, 1,6 Hexane diol diacrylate (HDDA) has been extensively explored in laser-based 3D microfabrication by microstereolithography. The thermomechanical properties of poly HDDA are important for their end use application in microcantilever-based sensors. The present work explores the optimization of these properties by copolymerization of HDDA and methyl methacrylate (MMA) for these specific applications. The dynamic mechanical analysis, thermal expansion and mechanical studies were carried out for different compositions of poly (HDDA-co-MMA). An increase in MMA content in the copolymer matrix resulted in the enhancement of the thermomechanical stability. The variations of thermal expansion coefficient (CTE) for different compositions were also studied. Microhardness, uniaxial tensile, and flexural tests along with Poisson's ratio were determined to understand the mechanical properties of these compositions. The scanning electron micrographs of fractured surfaces of all the compositions were analyzed to understand the fracture mechanism of various compositions of this copolymer. Figure 6. Scanning electron micrograph image of the surface fractured by tensile load for (a) PHDDA, (b) PMMA, (c) Phpm7525, (d) Phpm5050 at 800Â magnification, and (e) Phpm2575 at 400Â magnification.A. GOSWAMI ET AL.wileyonlinelibrary.com/journal/pat

Microfluidic valves made from polymerized polyethylene glycol diacrylate

“…The Young’s modulus for poly-PEGDA was determined from the pressure needed to deflect ~190 μm thick circular membranes with a 870 μm radius a distance of 20 μm (for linear deflection up to one half of the membrane thickness) using equation (1) [35], where P is the applied pressure in Pa, E is the elastic modulus in Pa, r is the membrane radius in m, h is the membrane thickness in m, ν is the Poisson’s ratio (estimated to be 0.35 from data reported for poly(methyl methacrylate) or PMMA [36]), and y is the deflection (in m) at the membrane center.…”

Modeling the free-radical polymerization of hexanediol diacrylate (HDDA): a molecular dynamics and graph theory approach

“…For a conversion of around 0.8, we found a glass transition temperature close to 400 K. Goswami et. al 58 determined the glass transition of pHDDA to be 359 K by using Dynamical Mechanical Analysis (DMA) and to be 328 K by using Thermo-Mechanical Analysis (TMA). It is well known that the glass transition temperature expected from molecular simulations can be higher than the experimentally observed one because the glass transition is a kinetic phenomenon and therefore depends on the cooling/heating rate.…”

Study of Thermal Relaxation of Poly (HDDA-co-MMA) by Temperature Modulated DSC and Dielectric Spectroscopy

“…The lower activation energy indicates higher free volume in terms of coefficient of thermal expansion [54] . PMMA shows higher free volume in terms of thermal expansion coefficient than other copolymers discussed in this study [55] . In addition, the dipole component of PMMA is on the flexible side chain and hence has a higher rotational and translational motion [9] .…”