The Effect of Molecular Structuring of an Incompatible Linear Polymer-Net Polymer System on Its Micro-Heterogeneity under the Effect of 3d-Metal Chelates

Abstract

The influence of the nature of the central ion [Cu(2+), Cr(3+), Fe(3+)] of the chelate compound on the possibility of interaction of the metal-containing modifier with one or both of the components of the incompatible PU/PMMA system was studied by the ESR method. It was shown by low-angle X-ray diffraction that the change in the degree of microheterogeneity of the semi-IPN correlated with the characteristics of complex forming metal and the polymer matrix.The possibility of the introduction of metal ions into the matrix (polymerization of metal-containing precursors, chemical bonding to the polymer chain, filling, etc.), the nature of the metal ion, its electronic configuration, and the structure of the organometallic modifier, in addition to the nature and conditions for the formation of the polymeric matrix, affect the properties of the metal-containing polymers formed in situ and the processes of their structure formation [1-6]. The interpenetrating and semi-interpenetrating polymer network (semi-IPN) based on the incompatible components is characterized by the microheterogeneity of the structure on the nanoscale caused by the incomplete process of microphase separation [1,4,6], which may result from the important affect of the presence of metal complexes in the reaction mixture.In the present work the structural formation in situ of semi-interpenetrating polymer networks based on incompatible pairs of polyurethane and linear polymethylmethacrylate networks in the presence of Cu(2+), Cr(3+), and Fe(3+) chelates was studied. EXPERIMENTALThe semi-IPN were obtained by simultaneous formation of a polyurethane network (PU) and polymethylmethacrylate (PMMA), carried out by various mechanisms (ionic and radical polycondensation respectively). The PU network was obtained by the interaction of trimethylolpropane with a macrodiisocyanate based oligo-oxypropylenglycol (OPG) M = 1000 and toluidene diisocyanate (a 65/35 mixture of 2,4-and 2,6-TDI ). Methyl methacrylate with 2,2¢-azobisisobutyronitrile (0.005 mol/L) was introduced into the reaction mixture. During the formation stage 1% by mass of iron acetylacetonate [Fe(acac) 3 ], chromium acetylacetonate [Cr(acac) 3 ], or copper ethyl acetoacetate [Cu(eacac) 2 ] was introduced. After consolidating the composition between parallel glass sheets, the protected sheets were cushioned with silicone, and the samples were heated at 333 K in vacuum to constant weight. 0040-5760/05/4104-0265

Kinetics of formation of a linear polymer-polymer network system in the presence of 3d metal chelates

“…This is consistent with preferential binding of Cr(acac) 3 to the polyether component of polyurethane [6], which should not be appreciably affected by an increase in the polyurethane fraction in the system.…”

“…Donor-acceptor bonding of polar groups from two incompatible components of the mixture promotes incompleteness of phase separation, like the kinetic conditions and diffusional constraints. Targeted slowing of phase separation in such systems can be done by introducing special additives (compatibilizers), forming chemical and/or donor-acceptor bonds with the components of the mixture [2][3][4][5][6].…”