NMR study of the microstructures and water-polymer interactions in cross-linked polyurethane coatings

TY - JOUR

T1 - NMR study of the microstructures and water-polymer interactions in cross-linked polyurethane coatings

AU - Zhu, Haijin

AU - Huinink, Hendrik P.

AU - Adan, Olaf C.G.

AU - Kopinga, Klaas

PY - 2013/8/13

Y1 - 2013/8/13

N2 - The microstructure of a polymer coating plays an important role in the water uptake behavior. This paper aims to correlate the molecular mobility and the water-polymer interactions with the microstructures of a highly cross-linked PU system. GARfield NMR imaging was used to monitor in situ the water uptake of the PU coating at different temperatures. The results of continuum T 2 fitting show that at temperatures below the enthalpy relaxation temperature (65 C) the PU coating uptakes water, whereas the polymer matrix is not plasticized by the presence of water. At higher temperatures, however, the polymer matrix is significantly mobilized by the presence of water molecules as indicated by the appearance of the longer T2 component. The water content in the PU coating is monitored by GARfield NMR at different temperatures. The results show that the water content decreases in two steps as the temperature decreases from 85 C to the room temperature. This result is explained in combination with the molecular relaxation phenomenon probed by the DSC. A microstructure model was formulated based on the experimental results.

AB - The microstructure of a polymer coating plays an important role in the water uptake behavior. This paper aims to correlate the molecular mobility and the water-polymer interactions with the microstructures of a highly cross-linked PU system. GARfield NMR imaging was used to monitor in situ the water uptake of the PU coating at different temperatures. The results of continuum T 2 fitting show that at temperatures below the enthalpy relaxation temperature (65 C) the PU coating uptakes water, whereas the polymer matrix is not plasticized by the presence of water. At higher temperatures, however, the polymer matrix is significantly mobilized by the presence of water molecules as indicated by the appearance of the longer T2 component. The water content in the PU coating is monitored by GARfield NMR at different temperatures. The results show that the water content decreases in two steps as the temperature decreases from 85 C to the room temperature. This result is explained in combination with the molecular relaxation phenomenon probed by the DSC. A microstructure model was formulated based on the experimental results.

UR - http://www.scopus.com/inward/record.url?scp=84881562272&partnerID=8YFLogxK

U2 - 10.1021/ma401256n

DO - 10.1021/ma401256n

M3 - 文章

AN - SCOPUS:84881562272

SN - 0024-9297

VL - 46

SP - 6124

EP - 6131

JO - Macromolecules

JF - Macromolecules

IS - 15

ER -