Phenyl Isocyanate Method for Determination of Hydroxyl Equivalent Weights of Polyoxyalkylene Compounds.

Migration of photoinitiators and their photoproducts are a major problem when it comes to food packaging or applications in the medical sector. Frequent coincidence with leachables and humans can be problematic, especially over time. Therefore, a new class of biocompatible photoinitiators, the aliphatic α‐ketoesters, were selected to be immobilized. Biocompatibility and low leaching were achieved using the metabolite α‐ketoglutaric acid. Immobilization of the photoinitiator is obtained via a macromolecular or copolymerizable approach.

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“…Three blanks were treated equally. As soon as the conversion reached >99% (1), the synthesis was finished and the IPDI‐HEMA could be characterized.

italicNCO ([] %) = \frac{((), V_{acid} - V_{blank}) * c_{titer} * M_{NCO}}{m_{sample} * 0.01}

V acid = hydrochloric acid solution for the sample [L]. V blank = hydrochloric acid solution for the blank value [L].…”

Section: Methodsmentioning

confidence: 99%

Biocompatible photoinitiators based on poly‐α‐ketoesters

Taschner

Gauss

Knaack

et al. 2020

Journal of Polymer Science

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“…Polyesters (13), polyamides (13), and polyurethanes (16) have been subjected to this analysis. Polyethers have been analyzed by hydroxyl-group titrations similar to those used for polyesters or by reaction with excess phenyl isocyanate followed by reaction with excess di-n-butylamine; the latter was backtitrated with perchloric acid (17). Nonaqueous titrations (18) have been used to characterize polysulfones with Mn values of up to 25,000.…”

Section: Number-average Molecular Weightmentioning

confidence: 99%

Molecular Weight Determination

Cooper

2004

Encyclopedia of Polymer Science and Technology

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Methods to determine molecular weight averages and distributions of polymeric and oligomeric materials have been devised and developed over many decades. Most of the early classical techniques were primary methods which usually yield only a single molecular weight average, based on theory and measurable constants. Of the classical methods only ultracentrifugation can determine a molecular weight distribution. Secondary methods, which depend on the availability of calibration materials, have largely supplanted the older classical techniques. Methods based on fractionation, with molecular weight characterization of the fractions, or chromatography, with continuous determination of molecular weight, are currently used to generate molecular weight distributions. Newer methods based on dynamic light scattering and viscoelastic measurements are available to determine the molecular weight distribution of difficulty soluble materials. Development of methods to describe the molecular weight and compositional distribution of multimer polymers continues to be a vibrant research area.

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“…The phenyl isocyanate method for hydroxyl group determination (114) has been modified by the use of toluene diisocyanate as the reagent (108).…”

Section: Acidmentioning

confidence: 99%