ISSN:
0032-3888
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
Proper drying techniques prior to molding can eliminate the overall effects of moisture on the physicochemical properties of polycarbonate. Problems associated with moisture in polycarbonate during molding are described in detail. Moisture absorption is very rapid with the maximum allowable moisture content of 0.03 percent reached within 30 minutes at 49 percent RH and 75°F. Molding with excess moisture content causes a chemical and physical degradation resulting in reduction in tensile impact strength, tensile elongation, ultimate tensile strength, proportional limit and molecular weight. New and existing techniques and procedures for degradation detection were investigated, such as intrinsic viscosity, infrared spectrometry, and thermal methods of analysis. Gel permeation chromatography (GPC) proved the most satisfactory. GPC provided information on the average molecular weight and polydispersity.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/pen.760141202
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