Hydrolysis residues

In 1976, Meluch and Campbell at General Motors obtained a patent10 for a steam hydrolysis depolymerization of PUR. High-pressure steam hydrolyzes flexible PUR foams rapidly at temperatures of 232-316°C to form diamines and polyols. The diamines are distilled and extracted from the steam and the polyols are obtained from the hydrolysis residue. In 1977, Bayer AG obtained a patent for a continuous PUR hydrolysis process using a specially designed extruder.11... 

Similarly, the presence of sulfonate esters also indicates incomplete hydrolysis. Residual saponifiable material in a final AOS product is then a measure of the quality of the surfactant. In practice, such material can be extracted, subjected to drastic conditions of saponification, and the quantity of residual saponifiable material calculated. Methods have been developed which can be used for the determination of 10 or more ppm of saponifiable material in the neutral oil of AOS. Unfortunately, the procedures outlined below are now of historic interest only, since they give unrealistically high values for residual saponifiable material content. Methods listed in the sultones section are now the analyses of choice. 

Hydrolysis of polyamide-based formulations with 6 N HC1 followed by TLC allows differentiation between a-aminocaproic acid (ACA) and hexamethylenedi-amine (HMD) (hydrolysis products of PA6 and PA6.6, respectively), even at low levels. The monomer composition (PA6/PA6.6 ratio) can be derived after chromatographic determination of the adipic acid (AA) content. Extraction of the hydrolysate with ether and derivatisa-tion allow the quantitative determination of fatty acids (from lubricants) by means of GC (Figure 3.27). Further HC1/HF treatment of the hydrolysis residue, which is composed of mineral fillers, CB and nonhydrolysable polymers (e.g. impact modifiers) permits determination of total IM and CB contents CB is measured quantitatively by means of TGA [157]. Acid hydrolysis of flame retarded polyamides allows to determine the adipic acid content (indicative of PA6.6) by means of HPLC, HCN content (indicative of melamine cyanurate) and fatty acid (indicative of a stearate) by means of GC [640]. Determination of ethylene oxide-based antistatic agents... 

Preston, C. M., and Ripmeester, J. A. (1982). Application of solution and solid-state 13C NMR to 4 organic soils, their humic acids, fulvic-acids, humins and hydrolysis residues. Can. J. Spectrosc. 27, 99-105. 

Poly(vinyl alcohol) [9002-89-5] is obtained by hydrolysis of poly(vinyl acetate). Commercial grades of poly(vinyl alcohol) differ in the degree of polymerization (molecular mass) and degree of hydrolysis [residual poly(vinyl acetate) content]. 

Table I. Hydrolysis residue, monosaccharide composition, and starch content of oat spelts from different sources...

Origin Hydrolysis residue Xylose Arabinose Total glucose Glucose from starch... 

Figure 3. Effect of H2O2 charge on brightness and hydrolysis residue of xylans derived from non-pressurized and 02-aided extraction (Ref = starting xylans)...

One of aromatic degradation products in the steam hydrolysis residue of birchwood (Betula pubescens) [7419]. 

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