A new method to evaluate solvent stress cracking

Abstract

The effect of crystallinity on the crazing process in isotactic polypropylene (i‐PP) was investigated by using a new static crazing experiment. Strips of i‐PP films are stressed in glass cones, which are placed into a series of solvents. Characterization of the films was performed by hot‐stage optical microscopy, scanning electron microscopy, wide‐angle X‐ray scattering, differential scanning calorimetry, and contact angle goniometry. The affinities of the solvents for the polymer were investigated by dynamic solvent uptake measurements. Crazing experiments revealed that both the sample preparation and the solvent choice play an important role in the crazing process. A “good” solvent is shown to be a “bad” crazing agent, whereas an intermediate solvent behaves as a “good” crazing agent. Two opposite processes are shown to take place: appearance of void and solvent‐induced crystallization.

Atomic force microscopic study of the structure of high‐density polyethylene deformed in liquid medium by crazing mechanism

“…Since polymer breakage is preceded by nucleation of crazes and cracks, the service properties of polymers are estimated based on the monitoring of their appearance upon the complex action of an ambient liquid and stress. In the literature, this phenomenon is referred to as environmental stress cracking/crazing, and the studies in this field are focused on the suppression or deceleration of the development of crazes and cracks with the aim to enhance the resistance of polymers to environmental effects (Cornélis & Kander, ; Lagaron et al ., ; Plummer et al ., ; De Focatiis & Buckley, ).…”

Hybrid Microfluidic Sensors Fabricated by Screen Printing and Injection Molding for Electrochemical and Electrochemiluminescence Detection

“…Zeonor exhibits excellent chemical resistance whilst HIPS has a lower chemical resistance but is suitable for the proposed application. When HIPS and SAN were used as substrate for printing, some crazing on the wider tracks of the printed carbon ink was clearly visible through the entire width and thickness of the line which was thought to be due to solvent stress [30]. However, when Zeonor was used, because of its high solvent resistance properties, the printing was more successful and the tracks were smooth and well defined and there was no cracking or crazing even after the curing stage.…”

A new method to quantify crazing in various environments

“…Previously, a wide variety of techniques have been employed to study crazing behavior in polymers. The most basic detection method that has been used is visual observation (1,2). This approach yields a good qualitative approximation of craze initiation in cases of exposure to certain organic solvents that cause extreme amounts of crazing in a short period of time.…”