Stereoregular Polymer

stereoregular polymer

[¦ster·ē·ə′reg·yə·lər ′päl·i·mər]
(organic chemistry)

Stereoregular Polymer

 

(also stereospecific polymer), any one of the polymers whose linear molecules consists of monomeric units having either identical spatial configurations or configurations that, while not identical, alternate in regular fashion. Stereoregular polymers of the first type include, for example, isotactic polymers’and 1,4-cis- and l,4-trans-polydienes, while those of the second type include syndiotactic polymers.

In many cases, stereoregularity is a necessary condition for realization of a crystalline state. Stereoregular polymers often have an array of mechanical properties that are superior to those of the corresponding nonstereoregular polymers. Stereoregular polymers include isotactic polypropylene, syndiotactic polyvinyl chloride, and stereoregular butadiene rubber, which are produced industrially, and certain natural polymers, such as cellulose and natural rubber.

References in periodicals archive ?
The poly(methacrylic acid) derived from the above PTrMA with a high optical activity was confirmed to be highly isotactic as expected and completely optically inactive, indicating that the stereoregular polymer could not maintain the helical structure without the bulky triphenylmethyl groups.
Both the P-E polymers and stereoregular polymer products exhibit similar behavior.
The stereoregular polymers are shown to be different from the P-E polymers at equivalent ethylene content due to differences in defect content in the PP sequences.
Optimization of structure-property relationships requires a fundamental understanding of the crystallization kinetics of this new type of stereoregular polymer, whose potential applications as an engineering thermoplastic have been extensively examined.
Although stereoregular polymers are generally thought of as homopolymers like polypropylene, the short comonomer runs found in ethylene copolymers are still stereoregular (ref.
Boudreaux (22) described a process for the manufacture of grafted stereoregular polymers of branched higher (alpha-olefins) with relatively high melting points, preferably grafted polymethylpentene containing a thioaliphatic compound.
Would people really be turned on by 'stereoregular polymers' and silicon chips?
In Reynold's laboratory, he and his students are working on both the development of new two-dimensional NMR methods for characterization of complex organic compounds, and their applications to structure elucidation of natural products and stereoregular polymers.