Desenvolvimento de blocos pré-moldados à base de polipropileno reciclado produzido a partir de mistura à quente

Abstract

In order to guarantee environmentally sustainable composites, the present study aims to develop a new material consisting of stone dust and gravel in brick format, bound together by recycled polypropylene through heat treatment aiming for application in masonry in civil construction. A systematic review was carried out to incorporate into the study a broad view of the data available in the literature regarding the manufacture and characterization of polymer composites. With the main focus of promoting studies on the composite using the polymer in different proportions - 15%, 25% and 35% by weight - as an optimizing form for future applications in favor of high resistance and low permeability, the blocks were molded and pressed in an own machinery developed for this purpose and the research was based on an adapted methodology involving tests of simple compressive strength, flexural tensile strength, water absorption by immersion, optical microscopy, among other tests to characterize the materials involved, such as the creep of polypropylene and thermal analyzes of thermogravimetry and its derivative (TGA AND DTG) and differential thermal analysis (DTA). Different aggregate contents – 28%, 37.5% and 57% – were used to prepare the composite. The results showed that the mechanical strength of the brick became increasingly dependent on the polypropylene content, reaching around 18 MPa for compressive strength and 4 MPa for flexural tensile strength, as the voids were filled with polymer, reaching a maximum absorption of around 5% and a maximum degree of saturation of 28%. On the other hand, the gradation of the aggregates was found to play a significant role in the strength of the bricks. Thus, it is noteworthy that the composites, mainly of the 35% recycled polypropylene type with fine grain size, showed satisfactory behavior in terms of resistance parameters, as well as in terms of compactness and water absorption standards, which justify their use in structures and construction elements.