Vol.:(0123456789) 1 3 J IRAN CHEM SOC DOI 10.1007/s13738-017-1204-z ORIGINAL PAPER Solvent‑free synthesis of tris(4‑hydroxybutyl acrylate) phosphate in the presence of 1‑methylimidazole Gheorghe Ilia 1,2  · Lavinia Macarie 1  · Nicoleta Plesu 1  · Smaranda Iliescu 1  · Adriana Popa 1   Received: 22 April 2017 / Accepted: 19 September 2017 © Iranian Chemical Society 2017 used as dispersants, plasticizers, fame retardants, solvents, hydraulic, fuids extraction antifoam agents, agents, adhe- sives, antistatic agents, coatings for textile, wetting agents, emulsifers, corrosion inhibitors and antifriction additives [4–8]. Phosphate esters’ synthesis represents an important chemical reaction in organic synthesis. The use of POCl 3 as a phosphorylating agent was frst proposed in 1857. It is one of the most widely used phosphorylating agents for alcohols [9]. Reaction of a phosphorochloridate with an alcohol is carried out either: (a) through the formation of an alkoxide [10]; (b) by using proton scavengers such as pyridine [11] or triethylamine with or without a nucleophilic catalyst [12]; (c) by employing Lewis acid catalysts such as TiCl 4 [13]; (d) using nucleophilic catalyst 4-dimethylaminopyridine [14]. The reaction of phosphorus pentoxide and fuorinated alco- hols has been investigated in order to synthesize (per)fuoro- polyether phosphate esters. The reactivity strongly depends on the structure of the fuorinated alcohol and decreases with increasing acidity. Moreover, the addition of a controlled amount of water to fuorinated alcohol allows the control of the monoalkylester and dialkylester contents in the fnal products [15]. In this paper, we present the synthesis of new tris(4-hydroxybutyl acrylate) phosphate, using phosphorus oxychloride and 4-hydroxybutyl acrylate, in the presence of 1-methylimidazole, without using organic solvent. The synthesized phosphate ester was further used as monomer for obtaining crosslinked polymers or copolymers by UV curing, polymers having fame retardancy properties. The synthesis of that phosphate can be included in the green chemistry methods because no solvent was used in synthesis and the UV polymerization can be considered environmen- tal friendly because also no solvent is needed. One of the advantages of this phosphate ester consists in the obtaining of polymers having blocked the hydroxyl end chain groups which allow the expansion of their applications. Abstract In this paper, we present the synthesis of tris(4- hydroxybutyl acrylate) phosphate using 1-methylimidazole as acid scavenger for hydrochloric acid by-product, when an ionic liquid is formed. The synthesis was performed in the absence of any organic solvent. The yield is 83% for ester. The phosphate was characterized by 1 H– 31 P NMR and FTIR. The obtained phosphate is appropriate monomer for UV curing in the presence of photoinitiator. The obtained polymer was characterized by thermal analysis and LOI. The results showed good thermal stability and fame retardancy of UV-cured polymer. Keywords Tris(4-hydroxybutyl acrylate) phosphate · 1-Methylimidazole · Ionic liquid · UV curing Introduction Organophosphorus compounds have found a wide range of applications in the area of agricultural, medicinal and indus- trial chemistry, or as synthetic intermediates [1]. Phosphate esters, used in industrial products from the middle of twen- tieth century [2], are a class of anthropogenic organic com- pounds found in the environment as a result of the release from commercial and industrial products [3]. These com- pounds represent an important class of commercial additives * Gheorghe Ilia ilia@acad-icht.tm.edu.ro 1 Institute of Chemistry, Timisoara of Romanian Academy, 24 Mihai Viteazul Bvd, 300223 Timisoara, Romania 2 Faculty of Chemistry-Biology and Geography, West University Timisoara, 16 Pestalozzi Street, 300115 Timisoara, Romania