Synthesis of hydrosoluble polymers of oxazoline using Maghnite‐H as catalyst

Abstract

2,4,4-Triméthyl-2-oxazoline was polymerized, using an acid exchanged montmorillonite clay as catalyst, with the aim to study the influence of the methyl group size in the initiation and propagation processes. The effect of amount of catalyst temperature, time, and solvent on the polymerization yield and viscosity of the polymers were studied. The polymers obtained were characterized by spectrometric methods and their average molecular weights were determined by viscosimetrie and GPC data. The polymers presented similar spectrometric results and narrow molecular weight distributions. The kinetics indicated that the polymerization rate is first order with respect to monomer concentration. The polymerization results showed that the methyl groups present in the monomer affected the initiation process. Mechanism studies showed that polymerization of TMOX involves nucleophilic ring opening by attack of nitrogen to cleave the CH 2 À ÀO bond of the oxazoline ring.

Alternative to Poly(2-isopropyl-2-oxazoline) with a Reduced Ability to Crystallize and Physiological LCST

“…CROP of 2-oxazolines substituted with R 2 leads to a higher conversion of the monomer when compared to 2-oxazolines with R 3 . Usually, 2-oxazolines with R 2 substituted by methyl [ 29 , 30 , 31 ] or ethyl [ 17 , 32 , 33 , 34 , 35 ] groups are used, but the polymerization of 2-oxazolines with –C(O)OCH 3 or phenyl [ 35 ] R 2 substituents is also known. As, at the same time, we aimed to assure the LCST at a temperature close to the physiological value, the role of the R 1 substituent of the comonomer is also crucial.…”

Synthesis of copolymer from 1,3,5‐trioxane and 1,3‐dioxolane catalyzed by Maghnite‐H+

“…37 Recently, an Algerian proton exchanged Montmorillonite clay called Maghnite-H þ (Mag-H þ ), a new non toxic cationic initiator, was used as a catalyst for cationic polymerization of a number of vinylic and heterocyclic monomers. [39][40][41][42] In the present work, we present a new approach to synthesis a copolymer of TOX by the cationic copolymerization of TOX with DOX in solution catalyzed by Mag-H þ (Fig. 1).…”

Poly(cyclic imino ether)s Beyond 2‐Substituted‐2‐oxazolines

“…[56] Montmorillonites have both BrØnsted and Lewis acid sites and when they are exchanged with cations that have a high charge density like protons, highly active catalysts for acid catalyzed reactions are produced. Magnite- (Figure 4), in which there is a complete saturation of montmorillonite with protons without destruction of the catalyst structure, can be used for first order polymerizations.…”