ISSN:
0021-8995
Keywords:
Chemistry
;
Polymer and Materials Science
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:
The infrared spectra of chlorinated polypropylene (CPP) are interpreted and tentative assignments of C - Cl stretching vibration of CPP are proposed. Recently, infrared spectrophotometry has been applied as a useful tool for the investigation of polymer transitions. The solid-state transition in isotactic polypropylene (IPP) was studied by infrared method in the range of -50° to 30°C; and from the temperature dependence of the peak absorbance, transition at -10°C was detected. This temperature of -10°C agrees well with the Tg2 detected by other methods. From these results, it is presumed that Tg2 is attributed to a motion (thermal expansion) of IPP segments in either crystalline and amorphous region. The thermal transition of chlorinated isotactic polypropylene (CIPP) was also examined with differential scanning calorimetry and infrared method, and two thermal transitions were observed. A higher transition (TH) has a minimum at a degree of chlorination of about 39 wt-%; and a lower transition (TL) changes linearly with increasing degree of chlorination. Infrared results indicate that TH may be associated with a motion (thermal expansion) in chlorinated segments, and TL may be associated with a motion in unchlorinated segments. These results of infrared studies also suggest that CIPP may have a block structure.
Additional Material:
12 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1972.070161018
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