The project proposal refers to a sustainable process of obtaining rigid polyurethane
(PUR) and polyisocyanurate (PIR) foams, cellular materials with excellent thermal
insulating and fire resistance properties. The process consists in chemically recycling
poly(ethyleneterephthalate) (PET) wastes, using as depolymerization and/or modification
agents renewable materials, mainly carbohydrates and natural oils derivatives. Novel
modified organocatalytic systems, different from conventional metallic compounds, will
be developed and optimized in order to increase process performance, maximize energy
efficiency and eliminate the need for solvents. The scientific challenge of the project
consists in tailoring the novel catalytic systems, in order to drastically reduce energy
consumption associated to the depolymerization reactions of PET wastes (in particular
in the presence of some renewable materials), and enhance catalytic activity for these
specific reactants, by using theoretical modeling, as well as experimental studies. In
this respect, research will be conducted in two main directions: i) modifying existing
organocatalysts, in order to improve their performance or their stability; ii) proposing
new organocatalyst that have not been used yet in catalyzed PET solvolysis. A library
of new modified organocatalysts and/or combinations thereof, with synergistic effect,
suitable for selective solvolytic attack of PET by various cleavage agents, will be, finally,
provided. Optimal versions will be selected, in order to be used to further develop the
technology for rigid PUR/PIR foams preparation, from PET wastes and renewable
resources.
Lab-scale technologies for synthesis of selected catalysts will furnish information,
useful for modifying commercial organocatalysts into new structures, or use new
organocatalysts for PET chemical recycling, in order to apply such energy efficient
technologies, on industrial scale.
The main objective of the project consists in developing a series of oligoester-poliols
with tuned chemical structure (i.e. rigid and/or flexible moieties content) and properties
(adequate for specific applications), starting from PET wastes and renewable materials,
by using the correlations between reaction parameters (including organocatalysts), the
products’ chemical structure and target properties. Using these oligoesters and designing
the foams formulations, polyurethane and polyisocyanurate thermo-insulating rigid
foams with tailored chemical structure will be obtained, adapted for various applications
and showing (in some embodiments) improved physico-mechanical and fire resistance
properties The innovative and flexible pilot-scale technology for oligoester-polyols
synthesis, using organocatalysts, as well as PET wastes and renewable resources as raw
materials, would represent an exemplary case of meeting “green chemistry” standards by
drastically reducing experimental conditions, eradicating the need for organic solvents,
recycling a plastic waste which is accumulating in land fields and is not biodegradable,
and providing, instead, innovative eco-friendly products, for long term applications. A
innovative and flexible pilot-scale technology for PUR and PIR thermo-insulating rigid
foams preparation using the respective oligoester-polyols will be developed, as well.
As a total result, a sustainable technology, with low energy consumption, significantly
reducing the price of rigid polyurethane foams, would provide an exceptional solution
to replace materials commonly used for insulation in buildings with new materials
exhibiting outstanding properties.