23 N M R Spectroscopy in the Characterization of Polymers Introductory Material E. G. BRAME, JR.
Downloaded by UNIV OF ARIZONA on January 14, 2013 | http://pubs.acs.org Publication Date: June 1, 1983 | doi: 10.1021/ba-1983-0203.ch023
Ε. I. du Pont de Nemours & Co., Inc., Experimental Station Laboratory, Wilmington, D E 19898
AMONG T H E EARLIEST APPLICATIONS OF N M R spectroscopy was the highly successful structure determination of polymers, including both homopolymers and copolymers. Many examples can be cited from the early literature including those attributed to Bovey and his colleagues. Bovey found the use of H N M R to be a fertile field to characterize the microstructure of hydrocarbon polymers. He used F N M R for characterization of fluoropolymers. In addition, Bovey pioneered the use of statistics to explain the numbers and relative abundances of lines in spectra. From those early days to the present, N M R continues to be one of the most important instrumental methods for characteriz ing the microstructures of polymers. Currently, C N M R , because of its larger dispersiveness, has mostly taken over this task from H NMR. In addition to the usual examination of polymers in solution and in the molten state, we are seeing a new surge of interest in the applica tion of C N M R to the examination of polymers in the solid state by magic angle spinning (MAS). This technique is providing new and sometimes different structural information about polymers because it is examining them in their natural states. Thus, with the use of MAS, along with the more common methods of examination, N M R has taken on an even more important role in its application to the determination of polymer structure. The chapters in this section cover the latest applications of N M R to polymer analyses. In addition, they show and even stress the impor tance of C N M R in polymer studies. Each chapter covers one or more aspects of C N M R in its application to polymers. Bovey shows how C N M R can be used to determine the structure of a commonly known material, polyethylene, as well as a less well-known material, Hytrel polyester elastomer. Polyethylene is examined in solution and Hytrel is examined in the solid state by MAS. Tonelli reports on the applica1
19
13
1
13
1 3
1 3
1 3
0065-2393/83/0203-0419$06.00/0 © 1983 American Chemical Society
In Polymer Characterization; Craver, C.; Advances in Chemistry; American Chemical Society: Washington, DC, 1983.
420
POLYMER CHARACTERIZATION
tion of C N M R i n the analysis of fluoropolymers. H e discusses the use of simultaneous d e c o u p l i n g of Ή a n d F from C to obtain very useful structural information about fluoropolymers. F l e m i n g shows that a variable temperature system can be useful i n e x a m i n i n g p o l y mers i n the s o l i d state by M A S . M a n d e l k e r n describes the use of C N M R relaxation parameters to determine nonordered regions i n semicrystalline polymers. F i n a l l y , F o r d states that C N M R s p i n lat tice relaxation times along w i t h line widths, nuclear Overhauser ef fects, and relative signal areas can be used to monitor cross-linking i n copolymers of styrene. 1 3
1 9
1 3
1 3
Downloaded by UNIV OF ARIZONA on January 14, 2013 | http://pubs.acs.org Publication Date: June 1, 1983 | doi: 10.1021/ba-1983-0203.ch023
1 3
A C C E P T E D October 1 4 , 1 9 8 1
In Polymer Characterization; Craver, C.; Advances in Chemistry; American Chemical Society: Washington, DC, 1983.
