## 1 Introduction  
With the significant growth rate of the population in the last decades, the consequent increase of pollution and waste production are issues of great relevance. The evolution and diversification of the production processes caused a continuous change in the quantities and compositions of urban solid waste, thus generating several problems related to transport, storage, and disposal. The possibility to re-use the waste in a sustainable way therefore assumes a primary importance, in order to improve the efficiency of waste management and to reduce its negative effects on the environment and the population [1; 2; 3]. The necessity to convert a waste in a raw material leads to the replacement of traditional disposal methods with recycling, thus allowing the separation based on the kind of waste and the redirection to the most suitable disposal and recovery treatment [4]. The most troubled waste class to be treated is surely the organic fraction of the municipal solid waste (OFMSW), due to its high-water content, that causes a rapid degradation and bacterial proliferation during its storage [5; 6]. OFMSW represents more than 40% by the weight of the municipal waste [7]. Furthermore, the high quantity of water contained in OFMSW determines a rapid decomposition that produces a high quantity of bacteria, which can turn into pathogens for humans and animals. However, incineration does not represent the best solution for OFMSW; it is, in fact, an expensive disposal method that causes air pollution. At the same time, this process does not stop the microorganisms from breaking down the OFMSW, therefore the groundwater gets contaminated by the leachate [8]. In addition, the degradation of the OFMSW in these conditions produces methane, which causes a greenhouse effect that is 25\(\times\) more powerful that the one generated from carbon dioxide [9]. Incorrect waste management practices can result in public health and environmental problems, such as odours and diseases [10]. These features make OFMSW quite complex to be managed. However, organic wastes are comprised of materials rich in sugars, minerals, and proteins that could be used in other processes as substrates or raw materials. Since the cultivation of microorganism requires carbon, nutrients, and moisture, organic waste could be, for example, a good candidate to provide the appropriate conditions for the development of microorganisms [2]. It is therefore essential to design a process, which allows a decrease in the bacteriological content and a longer storage of the waste. The production of a green composite based on OFMSW requires its incorporation into a matrix, which acts as a binder, thus reducing the danger of the waste. Nowadays, the most widespread application involves the use of inorganic matrices such as cement, clay, and lime [11; 12]. However, inorganic matrices have a series of disadvantages if used with organic waste. Firstly, they can be attacked by acids, causing the release of toxic material. In addition, cements and additives highly increase the weight of the waste. Furthermore, the main limitation is that the process is suitable only for the treatment of ashes that derive from the OFMSW combustion process, and it cannot be extended to materials rich of salts or organic components, since they can interfere with the setting and hardening processes, thus leading to the production of a very porous structure [13; 14]. An alternative to inorganic matrices consists of the use of organic reagents, such as thermoplastic [15; 16; 17; 18; 19; 20] or thermosetting polymers [1; 21]. Unlike the inorganic matrices, polymers do not chemically react with the waste, but carry out a process, which allows encapsulation of the OFMSW in the matrix. To the best of our knowledge, this represents an important and advantageous novel idea to process OFMSW.