[...]... measured, because if bands overlap, using peak heights may give more reproducible results since only the centre positions of the bands are used RESULTS AND DISCUSSION There are several regions of interest in the characteristic transmittance bands at 4000-400 cm-1 for CN and CA samples These bands occurred mainly due to the vibrations produced by the cellulose ring, ether linkages and substituent groups,... With Acetic Acid and Water, J Polymer Sci., 10 (1953), P385-423 Brydson, J A., Plastic Materials (3rd ed.), Butterworth Group, 1975, P493-4 Brydson, J A., Plastic Materials (2nd ed.), Iliffe Books Ltd 1969, P369 Haslam, J & Willis, H A & Squirrell, D C M., Identification and Analysis of Plastics (2nd ed.), Iliffe Books, 1972, P534-6 In: Chemistry and Chemical Engineering Reserch Progress ISBN: 978-1-61668-502-7... for acetates carbonyl impurities and deacetylation did not occur together and deacetylation is the major process of degradation INTRODUCTION Plastic grade cellulose esters are susceptible to degrading processes as a consequence of the chemical nature of the cellulose chain molecules and the substituents along the chain The rate of degradation is dependent upon the type and degree of substitution of the... desired environments simulated within them Anhydrous calcium chloride and distilled water were used to produce 0% and 100% relative humidity (RH) conditions, respectively The lids were put on tightly and the containers then placed in constant temperature ovens at 50-60oC for CN and 100oC for CA samples Samples were taken out periodically and analysed Sample Characterization All control samples were found... Organic Polymer Chemistry, Chapman & Hall Ltd., 1973, P255 Katz, S., Plastics / Designs and Materials, Macmillan Publishing Co Inc., 1978, P4244 Kaufman, M., The first Century of Plastics, Crown Press, 1963 Worden, E C., Nitrocellulose Industry, Van Nostrand, Vols 1 and 2, 1911 Philips, L., Nature, 160, 753, (1947) Miles, F D., Cellulose Nitrate, Interscience, 1955, P253 Adams, G K., and Bawn, C E H.,... to 5 show the results of peak ratio measurements carried out for CN and CA samples aged in both dry and humid conditions at various temperatures Figures 1 and 2 examine the effects of ageing on CA samples at 0, 100% relative humidity (RH) and 100oC The results in Figure 1 corresponding to peak ratio OH / CH3 for CA samples showed a progressive increase in values as the severity of ageing process increased... P493-494 Adelstein, P Z., McCrea, J L., J Soc Photog Sci and Eng., 7, (1981), 6 Ram, A T., McCrea, J L., Presented at the 129th SMPTE Technical Conference, Los Angeles, CA, (1987) In: Chemistry and Chemical Engineering Reserch Progress ISBN: 978-1-61668-502-7 Editor: A.K Haghi © 2010 Nova Science Publishers, Inc Chapter 2 DEGRADATION STUDIES OF CELLULOSE ESTERS USING PEAK RATIO MEASUREMENT TECHNIQUE A Hamrang*... used in this work included fabricated cellulose nitrate (CN, manufacturer not known) and cellulose acetate (CA, manufactured by Courtaulds, UK) plastic sheets, with no visible signs of degradation on them The thickness of CN and CA sheets was measured at 1.2 and 3 mm respectively The original samples were characterized and used as controls for subsequent ageing processes Degradation Studies of Cellulose... Reciprocal temperatures were calculated as (1 / T+273) where T is the four ageing temperatures of 50, 60, 70 and 80oC At each relative humidity condition and at each ageing temperature one value was obtained for example in Figure 1, at 15% relative humidity and at 50, 60, 70, 80oC, it took 111, 56, 20 and 5 days respectively for nitrates to lose 20% of their relative viscosity values For Figures 2 to 4 the... – PRM Technique All control and aged samples were dissolved in acetone and thin films cast at < 0.01 mm thickness A Nicolet Magna 560 FTR Spectrometer was used to record all spectra (spectra obtained using 64 scans at a resolution of 4 cm-1) The effects of ageing on samples were monitored by FTIR-PRM technique and the changes, which took place, were recorded The affected bands of the aged samples were .