000			01597nam a2200193Ia 4500
003			MX-MdCICY
005			20250625140642.0
040			_cCICY
090			_aB-10994
245	1	0	_aGPC and Structural Analysis of Polyurethane Degradation
490	0		_vPolymer PhotoChemistry, 7(4), p.273-287, 1986
520	3		_aLinear polyurethane (PUR)prepolymers were synthesized starting from diphenylmethane-4,4'-diisocyanate (MDI)and polyester diol oligomers. Two different types of polyester diols were used: poly(ethylene adipate)(PEA)and poly(ethylene/butylene adipate)(PEBA). The effects of UV irradiation on the photooxidative degradation of prepared PUR prepolymer were studied. The changes in the chain lengths and their distribution as well as the changes in chemical structure were followed. The GPC results show that the photooxidative decomposition is followed by a decrease in molecular mass together with an increase in polydispersity. This indicates a very inhomogeneous degradation, which is a consequence of the specific course and of the intensity of photooxidative degradation. This was confirmed by means of comparative IR and NMR measurements. Conclusions on the difference in behaviour of the two different types of polyester diols used in PUR synthesis were discussed.
700	1	2	_aRek, V.
700	1	2	_aMencer, H. J.
700	1	2	_aBravar, M.
856	4	0	_uhttps://drive.google.com/file/d/1ER2MQOda_h5c9h8mjdpI15pd_VdDILvH/view?usp=drivesdk _zPara ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx
942			_2Loc _cREF1
008			250602s9999 xx |||||s2 |||| ||und|d
999			_c45222 _d45222