ABSTRACT
Abstract The purpose of this study is to evaluate the effects of r-PET(polyethylene terephalate) and PG(propylene glycol) on the mechanical properties of polymer concretes made from recycled PET-based unsaturated polyester resin(UP). The polymer concretes are prepared with various PET, PG and stylene monomer(SM) contents. It is found out that the degree of unsaturation of the resin was the most important property affecting the thermal and mechanical properties. The cured unsaturated polyester resin or polymer concretes made with resins of higher degree of unsaturation showed higher glass transition temperatures, and strengths, compared with those made with resins of lower degree of unsaturation. Except for some concretes, the effect of PET and PG contents on the compressive strength of polymer concretes is recognized, and the strengths of polymer concretes made from recycled PET-based are almost the same as those made from UP used commercially, keywords: Polymer concrete, binder, polyethylene terephalate, unsaturated polyester resin
1 Introduction
PET is useful polymer used for fiber, film, and plastic containers such as carbonated beverage bottles. Recently, the recycling of polymers such as PET after use is attracting the attention of many researchers who are aware of environmental problems and attempts to find the ways to save earth resources. Previous studies showed that UP can be economically prepared from recycled PET and the resins may be useful for resin concrete(l-
3). However, there is little information on the molecular features of the UP. Resins using recycled PET offer the possibility of a lower source cost of materials for making useful polymer concrete products. Also the recycling of PET in polymer concrete would help to solve some of the solid waste problems caused by plastics and to save energy. Excellent strengths were obtained with polymer concretes using resins based on recycled PET. Resins using a maximum amount of recycled PET are desirable because they do not adversely affect the materials while they help decrease the cost of polymer concrete products, thus making them more competitive. This experimental study attempts to synthesize various UP from PET. This experiment systematically varies PET and PG contents using for glycolyses of PET, chain flexibility and degree of unsaturation of the resins and finds out the effects of those variables on the mechanical properties of polymer concretes made from recycled PET.
