title: Surface and interior views on origins of two types of banded spherulites in poly(nonamethylene terephthalate).
abstract: Top-surface and three-dimensional views of Type-1 and Type-2 of ring-banded spherulites in poly(nonamethylene terephthalate) (PNT) in thicker bulk crystallized on a nucleating potassium bromide (KBr) substrate were examined using various microscopy techniques: scanning electron microscopy (SEM), polarized-optical microscopy (POM), and atomic-force microscopy (AFM). In PNT crystallized at higher crystallization temperature (T(c)) with heterogeneous nucleating substrate, typically two types of ring-banded spherulites are present that differ significantly in patterns and ring spacings: Type-1 Type-2 (single- and double-ring-banded spherulites). Three-dimensional view on fractured spherulites in bulk PNT samples reveals that the single-ring-banded spherulite (Type-1) tends to be well-rounded spheres as they are nucleated homogeneously from bulk; the double-ring-banded spherulite (Type-2) is concentric hemisphere or truncated sphere shells owing to be nucleated from bottom. With confined thickness of films, the 3-D hemispheres in PNT may become truncated into multi-shell annular cones or arcs when thickness or growth is restricted. Based on the top-surface vs. interior views of banded lamellar assembly, origins and inner structures of dual types of ring bands in PNT were examined in greater details.
authors: Department of Chemical Engineering, National Cheng Kung University, Tainan, 701-01, Taiwan. emwoo@mail.ncku.edu.tw
authors: Eamor M
authors: EM
authors: Woo
authors: Siti
authors: S
authors: Nurkhamidah
authors: Yu-Fan
authors: YF
authors: Chen
mesh_terms: D010316:Particle Size; D010795:Phthalic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D010795:Phthalic Acids; D011108:Polymers; C569401:poly(nonamethylene terephthalate)