This paper reviews the possibilities of engineering novel macromolecular topologies via ΒͺlivingΒΊ ring-opening metathesis polymerization (ROMP) of miscellaneous macromonomers. It is shown that multibranched polystyrene poly(ethylene oxide) and polybutadiene polymacromonomers of varying compactness an
Preparation of polytetrahydrofuran monomethacrylate macromonomers by cationic ring-opening polymerization of tetrahydrofuran
β Scribed by Ying Guan; Wenchuan Zhang; Guoxiang Wan; Yuxing Peng; Peijun Ji; Jian Xu; Meiling Ye; Lianghe Shi
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 148 KB
- Volume
- 77
- Category
- Article
- ISSN
- 0021-8995
No coin nor oath required. For personal study only.
β¦ Synopsis
Polytetrahydrofuran monomethacrylate (MA-PTHF) macromonomer was prepared by cationic ring-opening polymerization(CROP) of tetrahydrofuran (THF) using boron trifloride etherate (BF 3 β OEt 2 ) as initiator and epichlorohydrin (ECH) as promoter. Two kinds of transfer agents were used: methacrylic acid (represented as TA1), and a mixture of methacrylic acid and sodium methacrylate (represented as TA2). The effects of polymerization conditions on molecular weight and molecular weight distribution of macromonomers were studied in this article, when the composition of reactants was kept constant. Under the same conditions, the molecular weight of macromonomer using TA2 is lower than that using TA1, which indicates that TA2 is more active than TA1. The molecular weight of MA-PTHF macromonomer varies with the polymerization time before transfer agents were added (T1), but molecular weight distribution remains constant. When T1 is limited in 30 min, the apparent numberaverage molecular weight of MA-PTHF increases significantly with the increase of T1, and ranges from 5000 to 18,000. Hence, the molecular weight of MA-PTHF macromonomer can be controlled by varying T1.
π SIMILAR VOLUMES
Three unsubstituted cyclic ketene acetals (CKAs), 2-methylene-1,3-dioxolane, 1a, 2-methylene-1,3-dioxane, 2a, and 2-methylene-1,3-dioxepane, 3a, undergo exclusive 1,2addition polymerization at low temperatures, and only poly(CKAs) are obtained. At higher temperatures, ring-opening polymerization (RO