Novel dielectrics from IPNs derived from castor oil based polyurethanes

Abstract

SYNOPSISThree series of interpenetrating polymer networks ( IPNs.) based on a polyurethane (castor oil + toluene diisocyanate ) with polystyrene, poly (methyl methacrylate), and poly ( nbutyl methacrylate) were synthesized and characterized. Dielectric relaxation studies of these IPNs were carried out from -150 to 100°C in the 100 Hz to 100 kHz range. The effects of structural variables such as composition, type of vinyl monomer, as well as the effect of interaction of the phases on the dielectric properties were studied. A certain degree of phase mixing was observed to exist in all series as detected by the variation of the glasstransition temperatures of the IPNs. Maxwell-Wagner-Sillars polarization at the interface of the two phases was observed.

Structure–property relationship of polyethylene glycol‐based PU/PAN semi‐interpenetrating polymer networks

“…Interpenetrating polymerization is a mode of blending two polymers to produce a mixture in which phase separation is not as extensive as it would be otherwise 7. IPNs synthesized so far exhibit various degrees of phase separation depending mainly on the miscibility of polymers 8–16. Hourston and coworkers8–10 carried out a detailed investigation of the synthesis and properties of various polyurethane/polyacrylate IPNs.…”

Effect of castor oil/polycaprolactone hybrid polyols on the properties of biopolyurethane

“…3,4 The physical properties of polyurethanes are significantly dependent on the composition ratio of soft to hard segments. [5][6][7] Also polyurethane is already well known to have excellent shape memory properties which are the ability to return from a deformed state to their original shape. [8][9][10] Biobased polyurethanes (BPUs) have attracted a great deal of scientific interest as ecofriendly materials for reduction of environmental pollution such as depletion of fossil oils, emission of carbon dioxide contributing to global warming, and nonbiodegradability after use of petroleum based polyurethane.…”

Simultaneous interpenetrating polymer networks based on epoxy-acrylate combinations

“…This amongst the IPN research groups. The kinetics of formation of IPN networks have been reviewed by epoxy-phthalic anhydride mixture will be designated by ''EP'' in the following, whereas the correSuthar et al 6 for various systems. Recent works 7,8 have shown that the greatest sponding cured portion will be named PEP.…”