释义 |
stereoregular, a. Chem.|stɛriːəʊ-, stɪəriːəʊˈrɛgjʊlə(r)| Also stereo-regular. [f. stereo- + regular a.] Of a polymer: having each substituent atom or group on the main polymer chain oriented in the same manner on the chain with respect to the neighbouring atoms or groups. Of a reaction: giving rise to such a polymer.
1959Gaylord & Mark Linear & Stereoregular Addition Polymers 473 The most significant new developments have involved the successful preparation of stereoregular polymers from monomers..which previously had only yielded atactic polymers. 1961Industr. Chemist Feb. 74/2 Although stereoregular polymers prepared with Ziegler-type catalysts are now of considerable commercial interest, research is continuing in attempts to obtain stereo-specific polymers by other, and perhaps less complex, catalysts. 1962Engineering 12 Jan. 57/1 The increasing commercial availability of the ‘stereo-regular’ synthetic rubbers. 1971Sci. Amer. Dec. 50/3 One striking example of the ability of catalysts to perform highly selective molecular alterations is the stereoregular polymerization of olefins pioneered by Karl Ziegler and Giulio Natta. 1979C. H. Bamford in R. N. Haward Developments in Polymerisation II. 251 Stereoregular poly(methylmethacrylate) can function, under suitable conditions, as a template for the polymerisation of the monomer. Hence ˌstereoreguˈlarity.
1959Jrnl. Polymer Sci. XLI. 80 A decrease in polymerization temperature could result in increased regularity as a result of a simultaneous improvement in stereoregularity, linearity, and head-to-tail structure. 1964Ibid. II. a. 4642 Stereoregularity was noticed in acetaldehyde polymerization only when solid borontrifluoride-etherate was used as the initiator. 1976Makromol. Chemie CLXXVII. 1475 The four catalyst systems employed for the cis polymerization..give polymers with a different degree of stereoregularity. This could depend on a different stereoregulating power of the catalysts. 1979Jrnl. Polymer Sci.: Polymer Chem. Ed. XVII. 2022 There was no significant difference between the stereoregularities of the polymers obtained with cesium naphthalene and fluorenylcesium as catalyst. This result indicates that the difference in initiator anions..did not affect stereoregulation. |