Characterization of strictly alternating hydrogenated poly[butadiene-alt-(1-olefin)] copolymers
✍ Scribed by Werner Gerum; Günther W. H. Höhne; Wolfgang Wilke; Manfred Arnold; Tino Wegner
- Publisher
- John Wiley and Sons
- Year
- 1995
- Tongue
- English
- Weight
- 683 KB
- Volume
- 196
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
The crystallization behaviour of the series of hydrogenated poly(butadiene‐alt‐ethene) to poly[butadiene‐alt‐(1‐hexadecene)] copolymers was investigated with the aid of differential scanning calorimetry (DSC) and X‐ray measurements. Hydrogenated poly(butadiene‐alt‐ethene) corresponds to polyethylene and crystallizes in the same way. Hydrogenated copolymers poly(butadiene‐alt‐propene) through poly[butadiene‐alt‐(1‐decene)] are completely amorphous. In these cases the large branching degree prevents crystallization of the main chains, whereas the side chains are too short to be able to crystallize above the glass transition temperature. The critical length is obviously reached in case of hydrogenated poly[butadiene‐alt‐(1‐dodecene)]. The part of the series with large side chains (hydrogenated poly[butadiene‐alt‐(1‐dodecene)] through poly[butadiene‐alt‐(1‐hexadecene)], shows the most interesting effects, especially hydrogenated poly[butadiene‐alt‐(1‐dodecene)], which shows crystallization depending on thermal history. In these substances the side chains are long enough to cause side‐chain crystallization, which becomes more pronounced with increasing length of the side chains. The crystal structure is not excactly to be determined, but some data indicate a model, in which the side chains are packed in a manner as in unbranched alkanes, but are also possible orthorhombic. However, the quality of the crystals formed is not very good, so these regions are better described as ordered domains rather than as crystallites.