Maureen reitman corporate vice president, principal and. This research studies the stress cracking of polycarbonate plastic by a variety of solvents and solvent blends. Its the reason you cant put stickers on your motorbike helmet. In some instances, structural degradation of the plastic may occur.
Even though the data indicates that some polymeric esters can be used at relatively high. This means that polycarbonate, polyacrylonitrilebutadienestyrene, and polymethyl. An introduction to plastics and rubbers in collections jstor. Our strategy will be to examine, in some detail, the roles of the three critical components of environmental stress cracking. In some instances, structural degradation of the plastic may occur with specific chemical agents and degradation can also be accelerated by high temperatures.
Plastic failure through environmental stress cracking. Evaluating environmental stress cracking of medical plastics. Some chemicals will affect various plastics, but not others. Taking some time for yourself to help reduce the stress you are feeling can make you more productive at work, as well as help. Its made of polycarbonate and the adhesive in the stickers will ruin the impact resistance of the helmet. Stress cracking of polycarbonate exposed to sunscreen. Characterising the environmental stress cracking behaviour. The potential for environmental stress cracking is of paramount concern when plastics are.
Find, read and cite all the research you need on researchgate. And finally, as is the case with so many properties, molecular weight is critical. Experience has shown that absorption of a liquid by a polymer may be better. Whereas some cracking results from excessive loads, or from. Environmental stress cracking esc is considered a leading cause of plastic part failure. Plastics that are highly prone to stress cracking may require an accelerator or surfaceinsensitive cyanoacrylate. Pdf stress cracking of polycarbonate exposed to sunscreen. In this study, the environmental stress cracking esc resistance of nanosio2 particlefilled polycarbonate pc was investigated at room temperature by using a fracture mechanical test method. Freeze fracture has proved particularly useful for examining the kinetics of. Some applications of fibre reinforced composites and their crack susceptibility. Chemical type, level of use, polarity, and severity of the environment all contribute to crack development in stressed polycarbonate. The goal of this article is to provide a framework for evaluating the suitability of a plastic for medical uses in terms of its stresscrack behavior. This problem is well known and is called environmental stress cracking.
Environmental stress cracking of polycarbonate catheter. Some emphasis is placed on the theory of fracture mechanics. A few plastics, among them pet and polycarbonate, can be entirely. Some scenarios are well known, documented or are able to be predicted, but. As little as 10 percent glass fiber can reduce problems with stress cracking in materials like polycarbonate and polysulfone. Improvement of environmental stress cracking resistance of polycarbonate by silicone coating. The results of this research can be used to develop targeted replacements for 1,1,1trichloroethane and cfc1, replacements that have equivalent or better compatibility with polycarbonate plastics.
Analysis of polycarbonate stress cracking and cleaning. Highly stressed parts are more likely to experience failure. Bring some life to her space with these adorable succulents. Environmental stress cracking esc is a slow crack growth process which. Environmental stress cracking esc is one of the most common causes of unexpected brittle. Evaluating environmental stress cracking of medical. The purpose of this paper is to illustrate the susceptibility of pc to hospital disinfectant chemicals and provide a practical example of stresscracking in the pc housing of a handheld medical. Windows made from polycarbonate often show evidence of crazing. Cracks, microcracks and fracture in polymer structures unitn. Polycarbonate cracking polymer engineering engtips. Stress cracking of polycarbonate exposed to sunscreen 2011010037 pushbuttons, knobs and plastic faceplates in automotive interiors are constantly exposed to chemicals such as sunscreen. The higher molecular weight materials will resist stress cracking for much longer and at higher critical stress levels.
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