FURTHER INVESTIGATION IN BANDED SPHERULITES OF POLY(ETHYLENE ADIPATE) AND POLY(BUTYLENE SUCCINATE) IN POLY(BUTYLENE SUCCINATE) / POLY(ETHYLENE ADIPATE) BLENDS
Banded structure in spherulites examined in a polarizing microscope has been extensively studied during the half past century and several views on this point have been made 1-3 though some of them may not be widely accepted. In addition, its of great scientific and technical interest that linear aliphatic polyesters which usually exhibit alternate bright and dark bands on appropriate conditions due to their biodegradability and can be used as environmental-friendly materials. In this work, we select poly(ethylene adipate) (PEA) and poly(butylenes succinate) (PBS) as model polymers to study the forming mechanism and the height distribution on the spherulites surface of the concentric rings with brightness alter periodically under polarizing optical microscope (POM) when crystallized from melt by real-space techniques means POM and AFM. For neat PEA, we found the PEA banded spherulite is made up of the alternate array of flaton lamellar and edge-on lamellar along radiating direction of spherulite which indicate the forming mechanism is lamellar twisting. To the best of our knowledge, this is the first time we observe the twisting lamellar in PEA banded spherulite by AFM and when compared the AFM images with POM results, it has been clear that bright ringed ribbons of banded spherulites under polarized light are composed of flat-on lamellar while the dark ribbons are comeposed of edge-on lamellar. Fig. 1 shows the height image which got from the cross region of PEA banded spherulite and it can be seen that edge-on lamellar constitute the ridge part and flat-on lamellar constitute the valley part of the banded spherulite. This is quite different from the common cases of banded spherulites of which the forming mechanism is lamellar twisting and the ridge is usually composed of edge-on lamellar. 4-6 We suggest this is probably due to the flat-on lamellar tilting depart from the substrate and aggregation (Fig. 2).
Tianchang Wang Shouke Yan
State Key Laboratory of Polymer Physics and Chemistry,Institute of Chemistry,the Chinese Academy of Sciences,Beijing,100190
国际会议
International Symposium on Polymer Physics(2008年国际高分子物理学术会议PP2008)
厦门
英文
87-88
2008-06-08（万方平台首次上网日期，不代表论文的发表时间）