Real-Time Infrared Determination of Photoinitiated Copolymerization Reactivity Ratios:  Application of the Hilbert Transform and Critical Evaluation of Data Analysis Techniques

Abstract

The reactivity ratios of various UV-copolymerizing systems were determined employing RT-FTIR spectroscopy, combined with advanced and alternative multivariate-statistical data analysis techniques. For complex mixtures peak identification as well as peak deconvolution has been increased significantly by employment of 2-dimensional correlation spectroscopy, based on the Hilbert transform. As an advantage, kinetic reaction profiles of homo-and copolymerization reactions have been extracted and have been separated without any additional measurement. The following reactivity ratios were obtained: fumarate/vinyl ether r 1 ) 0, r2 ) 0; maleate/vinyl ether r1 ) 0, r2 ) 0; fumarate/allyl ether r1 ) 0, r2 ) 0; maleate/allyl ether r1 ) 0, r2 ) 0; fumarate/methacrylate r1 ) 0, r2 ) 1.3; fumarate/acrylate r1 ) 0, r2 > 50; methacrylate/vinyl ether r1 ) 16, r2 ) 0; methacrylate/allyl ether r1 > 100, r2 ) 0; methacrylate/acrylate r1 ) 1.6, r2 ) 0.15; methacrylate/N-vinylcaprolactam r1 ) 7.3, r2 ) 0.01; and acrylate/ N-vinylcaprolactam r1 ) 1.3, r2 ) 0.01. Kinetically, the fumarate-vinyl ether copolymerization can be regarded as the homopolymerization of a CT complex while the fumarate allyl ether copolymerization should be regarded as a perfect alternating copolymerization. The HEA-NVC copolymerization has to be regarded as a terpolymerization between HEA, NVC, and the HEA-NVC charge-transfer complex.

Photocatalytic Properties of Tin Oxide and Antimony-Doped Tin Oxide Nanoparticles

“…These lower values were also reported earlier for similar formulations when radiation of 315 nm was used and can be explained by the large preference of a methacrylate radical end group to react with a methacrylate C=C double bond [12]. This phenomenon is well known for radical initiated polymerizations of mixtures of acrylate and methacrylate C=C bonds [12,14,29]. Hence, the C=C propagation step at the initial part of the polymerization reaction can be partly described as a reaction between a polymer fragment with a methacrylate radical end group and a methacrylate MPS C=C bond.…”

Novel concept of polymer electrolyte membranes for high-temperature fuel cells based on ETFE grafted with neutral acrylic monomers

“…2 gives the 95 % joint confidence interval of r HEMA and r HEA . Literature data of r HEMA = 1.60 and r HEA = 0.15 were derived from photo-initiated solution polymerizations [64]. The use of the membranes in fuel cell applications requires high proton conductivity, which may be reached via doping of the grafted membranes with phosphoric acid.…”

“…On the contrary, at low f HEMA the HEMA content in the copolymer calculated with literature r values is significantly higher than the data derived from graft polymerizations. These differences may partly be due to the fact that literature data were derived from experiments up to higher conversion and an associated drift in copolymer composition[64]. Additionally, it should be considered that two different polymerization types are compared: solution polymerization vs. grafting from a polymer film.…”

Syntheses of donor acceptor biobased photocurable water‐soluble resins based on poly‐l‐lysine

“…It must be pointed out that too high a grafting percentage (such as formulation 1) can result in too high a crosslinking density which implies lower mobility, and a lower degree of conversion. 39 As previously mentioned, this system is not very reactive and the maximal curing rate is low (close to 0.035 s 21 ). This is firstly due to the reactivity of the functional groups since ).…”