Influence of chemical stress on sulfur-polymer composite structure

Abstract

Sulfur- polymer composites are high performance thermoplastic materials made of mineral aggregate, filler, and modified sulfur binder, instead of cement and water as in ordinary Portland cement- based composites at temperatures above the hardening point of sulfur (120ºC). Using sulfur to obtain modified sulfur binder is based on its physicochemical characteristics. According to our terminology, modified sulfur binder considers a mixture of elemental sulfur and modified sulfur- sulfur polymer. Contemporary experience all over the world shows that composite materials with modified sulfur binder instead of cement and water have significant chemical and physico- mechanical advantages comparing with Portland cement- based composites. Modern trends of obtaining materials with desired properties are based on combining ingredients with different properties in different proportions, as well as on the application of various manufacturing procedures and additional material processing. Having in mind that while in service use, all materials are exposed to divers external influences that provoke some type of response, the idea of this research was to change the quality of sulfur- polymer composite by imposed chemical stress. Since sulfur- polymer composites are relatively new building materials that can potentially replace conventional material made with Portland cement as a binder in many branches of construction, it was found plausible to choose Portland cement- based composite as a referent material. In order to quantify the changes in the material structure as its response to the specific imposed stimulus, the scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) were applied. According to the applied analyses on micro level, it can be concluded that the initial structure of sulfur- polymer composite was rearranged. As a macro level result material with better resistance to chemically imposed stress compared with the referent material was obtained.