Abstract:

Almost everything used in human life is made up of chemical products. Up to date, chemical industries play and active role on the development of the economy and the enhancement of the welfare state. Notwithstanding, environmental concerns such as climate change, air pollution of environmental impact regarding chemical use are on the rise. Achieving sustainable development is one of the main challenges for chemical companies at present. In this context, green chemistry is an emerging philosophy of science that bears in mind the responsibility, ethics and the sustainable procedures.

During the last twenty years, Chemical Engineering Degree of the University of Girona (Spain) has been boosted new teaching techniques to enhance the students learning. In this sense, a novel procedure focused on the students self-learning and practical cases are conducted in Ecological Chemistry subject. The main themes of the course are based on the study of real problematics in the chemical companies and the suggestion of environmentally friendly alternatives. Moreover, the course is realized in English language in order to accomplish more competences of Bologna Declaration.

The studied case are related to the plastic industry. Polymers usually are characterized by a low stiffness. This is one of the main reasons for its reinforcement with fibrous materials for structural or semi structural applications. One of the most common reinforcement, nowadays, is glass fiber. Anyway, this inorganic reinforcement presents some drawbacks as its abrasiveness, high environmental impact and unhealthiness. In this sense, lignocellulosic fibers have postulated as a substitutes. Nonetheless, in some applications the substitution of mineral reinforcement by biodegradable fibers is not enough. Thus, the hybridization of reinforcement gives the opportunity to improve the properties of natural composites, minimize the harmful effects of glass fibers and replace one type of reinforcement with another one, less expensive and more sustainable.

Even so, natural fibers continue reinforcing oil-based polymers. Actually, the efforts are also concentrated on the substitution of oil-based polymers by biodegradable ones. The most promising biomaterial is polylactic acid. Its mechanical properties are remarkable, being higher than commodity plastics such as polypropylene. However, the feasibility of cost-effectively manufacturing the polylactic acid is complex. Due to low cost and availability, blending PLA with starch can be a good solution to reduce the manufacturing costs. Nonetheless, the poor processability and the mechanical properties are the limiting factors for starch.

In this study, students test the mechanical performance and study the processability of different typologies of hybrid and non-hybrid composites. Then, they prepare a report, where they discuss the pros and the cons of different kinds of reinforcement and polymers. The report needs to be argued in terms of manufacturing processes, economical costs and environmental dilemmas. It is required a report supported by consistent literature. The recollected results of 2016-2017 course were satisfactory. Nonetheless, some improvements were proposed to increase the quality of the study case.

Keywords:

Transversal competences, English language, green chemistry, chemical engineering, sustainable economy, renewable alternatives, hybrid composites, biodegradable polymers, natural fibers.