Wortmann, Martin published the artcileEffect of Isocyanate Absorption on the Mechanical Properties of Silicone Elastomers in Polyurethane Vacuum Casting, Recommanded Product: 4,4-Diaminodicyclohexyl methane, the publication is ACS Omega (2021), 6(7), 4687-4695, database is CAplus and MEDLINE.
Polyurethane vacuum casting with silicone molds is a widely used industrial process for the production of prototypes and small batches. Since the silicone casting molds absorb the isocyanate component of the curing PUR casting resin at the cavity surface, the service life of the molds is typically restricted to very few casting cycles. The successive deterioration of the material properties results from the polymerization of the absorbed isocyanate with moisture to polyurea derivatives within the silicone matrix. In this study, we show for the first time the influence of isocyanate absorption on the mech. properties of silicone elastomers as well as quant. differences between com. materials. The changes in mech. properties were quantified in terms of Shore A hardness, Young’s modulus, tensile strength, elongation at break, and complex shear modulus. It was found that the influence of the isocyanate type on the relative property changes of the silicone was significantly greater than that of the silicone used. The results show that, regardless of its hardness, the silicone absorbs considerably less methylene di-Ph diisocyanate (MDI) than hydrogenated MDI, although the latter causes less deterioration of the mech. properties and achieves a longer mold service life.
ACS Omega published new progress about 1761-71-3. 1761-71-3 belongs to quinuclidine, auxiliary class Ploymers, name is 4,4-Diaminodicyclohexyl methane, and the molecular formula is C65H82N2O18S2, Recommanded Product: 4,4-Diaminodicyclohexyl methane.
Referemce:
https://en.wikipedia.org/wiki/Quinuclidine,
Quinuclidine | C7H13N | ChemSpider