Filled interpenetrating networks: their formation and viscoelastic properties

Abstract

The kinetics of curing, the microphase separation process (MPS) and the viscoelastic properties of interpenetrating polymer networks (IPNs) based on crosslinked polyurethane and linear poly(butyl methacrylate) were studied in the presence of two fillers—talc and polymeric fine‐disperse triethylene glycol dimethacrylate. It was found that introducing filler into the reaction mixture changes the reaction kinetics and degree of microphase separation, which in turn affects the viscoelastic properties of the IPNs. The data obtained by dynamic mechanical spectroscopy and differential scanning calorimetry for filled semi‐IPNs and calculations of the degree of segregation of the components show that filler introduction results in MPS inhibition on account of a local increase in viscosity near the solid interface, i.e. compatibility is increased.

Interpenetrating Polymer Networks Based on Polyurethane and Poly(butyl methacrylate): Interrelation Between Reaction Kinetics and Microphase Structure

“…The ratio of PU/PBMA was 3 : 1. The methods are described in [40]. As fillers we have used: talc (3 MgO.…”

Phase-Separated Interpenetrating Polymer Networks

“…The value of t mps in the system drops sharply only with a component ratio of 65 : 35 and at higher initiator concentration. When the component ratio is changed at constant initiator and cross-linking agent concentrations, t mps increases to 70 min, the PU conversion declines from 0.5 to 0.3, and the BMA conversion varies within 0.03-0.20 [292].…”

“…However, using this equation for estimating the entanglement contributions meets with some difficulties, because the chemical cross-linking in IPNs does not coincide with that calculated from stoichiometry. For semi-IPNs based on cross-linked PU and linear PBMA, it was supposed [174] that E c = E ∞ (PU) because at all PBMA concentrations in semi-IPNs the glass transition of PU does not change. It was found that under such an assumption, the increasing PBMA content in the IPN increases the contribution of topological entanglements to the elasticity modulus.…”

“…The first attempt to describe theoretically the processes of phase separation during the reaction of formation of semi-IPNs has been done in the works [296,297]. Semi-IPNs based on PS and a reactive epoxy monomer based on DGEBA with a stoichiometric amount of 4,4 -methylenebis(2,6-diethylaniline) were studied experimentally.…”

“…From this point of view it is of interest to study the kinetics of IPN formation by introducing fillers. Such investigations were done for simultaneous semi-IPNs made from PU and PBMA in the presence of various amounts of mineral filler (talc, 3MgO·4SiO 2 ·H 2 O) and polymeric filler (cured polyester acrylate) [327,328].…”