Isophorone diisocyanate

The reagents for the synthesis of poly(urethane-acrylate) (PUA), namely polyethylene glycol (PEG 400), isophorone diisocyanate (IPDI), the catalyst dibutylbis(lauroyloxy)tin and the end-capping agent 2-hydroxyethyl methacrylate (HEMA), were purchased from Merck Life Science (Milan, Italy) and used without further purification.
Two types of waste were introduced, licorice root waste following the extraction of licorice juice by ethanol, which was supplied by Amarelli-Fallani, Rossano Calabro, Italy, and palm tree waste, which was supplied by Ecoflora 2, Ardea, Italy, a firm that is in charge of collecting and exploiting pruning waste in the Rome area.

Epoxidized palm olein (EPO) (OOC = 3.5%, acid value = 0.77 mg KOH/g sample) was procured from Advanced Oleochemical Technology Division of Malaysian Palm Oil Board (MPOB)(Bandar Baru Bangi, Malaysia). Glutaric acid, glycerol 99%, dibutyltin dilaurate (DBTL) and isophorone diisocyanate (IPDI) were purchased from Merck. Niax A33, triethylene diamine and Niax L580 silicone surfactant were purchased from SamChem Holding Sdn. Bhd. Polyethylene glycol (PEG, number average molar mass, Mn = 6000 g/mol) and polycaprolactone diol (PCL diol, Mn = 2000 g/mol) were purchased from Fischer Scientific (MA, USA). Porcine pancreas type II lipase (100–400 U/mg protein) and thiozolyl blue tetrazolium bromide (MTT) were purchased from Sigma-Aldrich (MO, USA). Dulbecco’s modified eagle medium (DMEM), fetal bovine serum (FBS) and penicillin-streptomycin (Brand: Gibco) were purchased from Bio-diagnostics (Giza, Egypt). Latex urinary (Idealcare^®, Kedah, Malaysia) and feeding (Ryle’s tube) catheters were purchased from a local pharmacy outlet. Human osteosarcoma MG63 cells were obtained from the cell bank of International Medical University (IMU, Kuala Lumpur, Malaysia). All chemicals and reagents used in the analyses were of analytical grade.

Priplast 1838 (dimer linoleic acid based polyester diol) was kindly provided by Cargill Bioindustrial (The Netherlands). Isophorone diisocyanate (98%, mixture of isomers) (IPDI) and 2-hydroxyethylmethacrylate (97%) (HEMA) were purchased from Merck KGaA (Germany). Phenothiazine (PTZ) was purchased from Sigma Aldrich (Poland). Photoinitiator Omnirad 819 was purchased from IGM resins (The Netherlands). Ethyl acetate (EtOAc) and methanol were purchased from Chempur (Poland). HEMA was used after distillation under reduced pressure; all other reagents were used as received. Magnesium chips and titanium(iv) butoxide were purchased from Sigma Aldrich (Poland), and n-butanol was purchased from Eurochem BGD (Poland). Murine fibroblast cell line, L929, as well as all cell culture reagents were purchased from Sigma Aldrich (Poland). All disposable cell culture plasticware was purchased from VWR (Poland).

1,4-butanediol (BD) was obtained from Carl Roth GmbH (Karlsruhe, Germany), while 1,6-hexamethylene-diisocyanate and isophorone-diisocyanate (HMDI and IPDI), polyethylene glycol, M≈200 (PEG), and Tween® 20 from Merck (Darmstadt, Germany). Mono-ethylene glycol (MEG) was purchased from Lach-Ner s.r.o. (Neratovice, Czech Republic). The substances that were necessary to obtain media with different pH values (phosphates, Glycine, HCl and NaOH, analytical grade purity) were obtained from SC Chimopar Trading SRL (Bucharest, Romania). All reagents were used without any previous purification.

All reagents such as butyraldehyde, dodecanal, octanal, hydro cinnamaldehyde, benzaldehyde, furfural, nitromethane, 1,1,3,3-tetramethylguanidine, nichel chloride hexahydrate (NiCl₂^.6H₂O), sodium borohydride (NaBH₄), ethanolamine, sodium acetate (NaOAc), cerium trichloride heptahydrate (CeCl₃^.7H₂O), sodium iodide (NaI), isophorone diisocyanate (IPDI), PEG 400, 2-hydroxyethyl methacrylate (HEMA), benzophenone and N-methyl diethanolamine were all purchased from Merck. Polyethylene terephthalate (PET) are 2–5 mm particle size pellets obtained by crushing PET bottle scraps. As the first treatment, diols and diisocyanate were dried at 50°C under vacuum conditions for 24 h to remove residual water, and all the aldehydes were previously distilled. In the case of air and moisture-sensitive reactions, the glassware was oven dried at 100°C for more than 2 hours before use, when the reactions were performed under an inert atmosphere (nitrogen gas). For thin-layer chromatography (TLC) analysis, Merck pre-coated TLC plates (silica gel 60 GF254 0.25 mm) were used. Products were observed under UV light or stained in 2,4-dinitrophenyl hydrazine or potassium permanganate solutions.