Crystallinity morphology and dynamic mechanical characteristics of PBT polymer and glass fiber‐reinforced composites

Abstract

ABSTRACT:The crystalline morphologies of PBT (poly butylene terephthalate) and its glass fiber reinforced composite systems were investigated in a thin-film form by polarized optical microscopy and wide-angle X-ray diffraction. Three different types of PBT morphology were identified in the Maltese cross pattern: 45°cross pattern (usual type) by solvent crystallization, 90°cross pattern (unusual type) by melt crystallization at low crystallization temperature, and mixed type by melt crystallization at crystallization temperatures higher than 160°C. The glass fibers increased the number density of spherulites and decreased the size of crystallites acting as crystallization nucleation sites without exhibiting trans-crystallinity at the vicinity of the glass fiber surfaces. Finally, the storage modulus was analyzed by using a dual-phase continuity model describing the modulus by the power-law sum of the amorphous-and crystalline-phase moduli. The crystalline-phase modulus was extracted out from the PBT polymer and composite systems containing different amount of crystallinity. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 478 -488, 2002

Solid state 1H NMR study of molecular dynamics and domain sizes in PBT with the fullerene derivates: Decylamine–C60 and tetracyanoethylene oxide–C60

“…(12) is 1 for a lamellar system, 2 for cylindrical geometry and 3 for spherical morphology. For PBT nanocomposites the constant ε was assumed as 3 [17].…”

In situ monitoring of cyclic butylene terephtalate polymerization by dielectric sensing

“…This is characteristic of crystalline lamellae growth during isothermal crystallization. Contrary to anisothermal crystallization from the molten state that usually shows a difference in crystallinity ratio when the cooling rate changes [20,21], the crystalline phase fraction is approximately 45% for all crystallization temperatures. If polymerization and crystallization were consecutive, that is to say that the molecular weight build-up was completed before the start of crystallization, the crystallization kinetics would not differ from melt crystallized PBT except for a time-shift equal to the time needed for polymerization.…”

Study of the abrasion resistance under scratching of polybutylenetereftalate–glass fiber composites

“…PBT-GF composites have been widely studied for their microstructure, thermal, mechanical and rheological properties [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. It is well known that the addition of short glass fibers can significantly strengthen neat PBT [3].…”

“…The viscoelastic recovery ability after abrasion of the unreinforced polymer is clearly higher after sliding in the direction parallel to injection flow than in the direction perpendicular to it. The viscoelastic recovery for the glass fiber composite materials is less dependant of direction due to their higher stiffness and resistance to deformation[1][2][3][4][5][6][7][8][9][10][11].SEM observation and cross section profilometry measurements have been applied to determine the main wear mechanisms which take place. Residual depth values quantify abrasive wear resistance by measuring the depth along the whole length of each groove, while cross section profile areas are an indicator of the main wear mechanism.…”