The Use of Ft-Ir and Dynamic Saxs To Provide an Improved Understanding of the Matrix Formation and Viscosity Build of Flexible Polyurethane Foams

Abstract

AbstractsFrom a technical viewpoint there are two choices. Firstly, a drop-in replacement for CFC-11, requiring no fundamental changes in terms of polyurethane foam processing; HCFC-141b, in this case, is a potential intermediate blowing agent. The second choice is to use blowing agents with boiling points below room temperature, referred to in this paper as Low Boiling Blowing Agents, or LBBAs. This option introduces some processing complications, but potential transitional materials such as HCFC-22 and HCFC-142b are readily available. This paper reports on ICI Polyurethanes' Research and Technology developments with a novel technology based on these HCFCs. The technology results in foams with reduced thermal conductivities compared to foams blown with reduced CFC-11 systems. Different aspects of the technology, including thermal conductivity performance, energy consumption data and relevant physical properties are discussed.Measurements of apparent thermal conductivity for specimens of rigid polyisocyanurate (PIR) foam cut from a commercial insulation product and aged in air at 60 ° C and different humidities are presented. Eight specimens, nominally 600 by 600 mm, were prepared from two boards (1.2 by 2.4 by 0.05 m) of rigid PIR foam blown with trichlorofluoromethane (CC13F) and having permeable organic-inorganic facers. Facers and excess foam were removed by sanding the specimens to a thickness of 27.9 f 0.1 mm. Four specimens were placed in ambient conditions of 22 ° C and 40% relative humidity (RH). The remaining four specimens were each placed in one of the following environments: (1) 60°C and < 10% RH; (2) 60 ° C and 40% RH; (3) 60 ° C and 60% RH; and, (4) 60 ° C and 75% RH. Measurements of apparent thermal conductivity were conducted at 24 ° C and a temperature difference of 22 ° C using a heat-flow-meter apparatus conforming to ASTM Test Method C 518. Measurements were conducted for a period of 357 days at approximately 50-day intervals. Aging curves of specimen mass, volume, density, and thermal conductivity for rigid PIR foam are presented, and implications of changes in these properties are discussed in the paper. Supplemental measurements using Fourier transform infrared spectroscopy and scanning electron microscopy are also described in the paper.

A Study of the Reaction Kinetics of Polyisocyanurate Foam Formulations using Real-time FTIR

“…The components of the pre-blend and catalyst levels are listed in Table 3. of urethane-urea matrices observed by IR has been well documented in recent years [12][13][14][15][16][17][18][19][20][21][22][23]. The generation and consumption of molecular profiles throughout the foam reaction are followed by observation of the peaks of FTIR band allocations as listed in Table 4.…”