Preparation and Analysis of Polyurethane Adhesives Containing Organometallic Catalysts

1 Preparation and Analysis of Polyurethane Adhesives Containing Organometallic Catalysts 

For the purpose of studying the effects of sample preparation and analysis of polyurethanes for organometallic catalysts, the metal salts listed in Table 6.24 were added at 0.1% each. 

Preparation of polyurethane samples for metal analysis requires destructive techniques because of their high molecular weights and high concentration of rubber and/or fillers. These products are not very soluble in glacial acetic acid, propylene carbonate, kerosene or white spirit. They will dissolve in chloroform xylene, toluene but these solvents are unsuitable for ICP-OES nebulisation because they flicker and give rise to noisy plasmas and quench the plasma during analysis. 

1 Ashing Methods for Metal Analysis of Polyurethane Adhesives 

Method. An accurate weight of approximately 2.0 to 3.0 g of each polyurethane listed in Table 6.24 is placed in a clean platinum dish with 0.15 g of PTSA. The samples are ashed using a program of ramping/holding stages similar to methods described for cyanoacrylate adhesives to a maximum temperature of 650 °C. The resulting ashes are contacted with 10.0 ml of 0.1 M HC1 and the suspensions transferred to a Teflon beaker. To each add 2.0 ml of cone. HF and heat to -150 °C on a hot plate to dissolve the SiC 2. The clear solutions are made up to mark in a plastic volumetric flask with deionised water. 

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