@article {7241,
	title = {OBSERVATION OF HETEROGENEOUS TRACE (0.4-PERCENT W/W) WATER-UPTAKE IN BISPHENOL A POLYCARBONATE BY NMR IMAGING},
	journal = {Chemistry of Materials},
	volume = {4},
	number = {2},
	year = {1992},
	note = {ISI Document Delivery No.: HL702Times Cited: 6Cited Reference Count: 17},
	month = {Mar-Apr},
	pages = {267-271},
	type = {Article},
	abstract = {The uptake of water by injection-molded bars of bisphenol A polycarbonate (Lexan 121 resin) has been monitored by a combination of one-dimensional proton NMR spectroscopy, relaxation time (T1 and T2) measurements, and microscopic imaging techniques. The bulk of the water absorbed in the initial stages (20-24 h) of 100-degrees-C water exposure is uniformly distributed throughout the polymer with a trace amount of the water found in clusters of 200-300-mu-m in size. The water that has aggregated to form these clusters is more mobile, having a T2 relaxation time 20 times longer than that found for the uniformly distributed water. At longer exposure times (30-40 days) the number of clusters is observed to increase. Although the total amount of water adsorbed is considerably less than 1 \% w/w, good-quality images are obtained, demonstrating that the NMR microimaging technique can successfully monitor even trace levels of solvent if the molecules are relatively mobile.},
	keywords = {DIFFUSION, mobility, NUCLEAR MAGNETIC-RESONANCE, POLYMERS},
	isbn = {0897-4756},
	url = {<Go to ISI>://A1992HL70200010},
	author = {Fyfe, C. A. and Randall, L. H. and Burlinson, N. E.}
}
