Crystallization kinetics of toughed poly(butylene terephthalate)/polycarbonate blends

Abstract

The crystallization kinetics of pure poly(butylene terephthalate) (PBT) and toughed modification PBT/polycarbonate (PC) blends with ethylene‐butylacrylate‐glycidyl methacrylate copolymer (PTW) and ethylene‐1‐octylene copolymer (POE) were studied. For nonisothermal crystallization process studies, the Ozawa theory and an equation combining the Avrami and Ozawa equation are used. It is found that the Ozawa analysis fails to provide an adequate description of the nonisothermal crystallization process in PBT, PBT/PC, and toughed PBT/PC blends, while the combination of the Avrami and Ozawa equations exhibit great advantages in treating the nonisothermal crystallization kinetics. The activation energies are determined by the Kissinger method for nonisothermal crystallization. The activation energy for PBT/PC/PTW/POE blend is greater than those of PBT/PC, and PBT/PC/POE blends. Isothermal crystallization processes were studied by the Avrami equation. The results show that the values of the Avrami exponent n for PBT, PBT/PC, and toughed PBT/PC blends are 3.8, 3.0, and 2.8–3.2, respectively. The Avrami rate constant K for PBT, PBT/PC, and toughed PBT/PC blends increase in following order: KPBT/PC < KPBT/PC/POE < KPBT/PC/PTW/POE < KPBT © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1295–1308, 2006

Hydrogen bonding interaction and crystallization behavior of poly (butylene succinate-co-butylene adipate)/thiodiphenol complexes

“…As a result, the mobility of PBSA chains decreased, leading to lower nucleation rates and hindered crystal growth. In addition, the crystallization peak with at half maximum ( PWHM ), proposed by many researchers to evaluate the crystal size distribution, increases with TDP as listed in Table , implying that spherulitic size of PBSA become less uniform in the presence of TDP. The effects of TDP introduction on crystallinity of PBSA were estimated using the following equation: where X c is the crytallinity of PBSA in samples, W is the weight fraction of TDP and the constant 110.5 J/g is the heat of fusion for 100% crystalline PBSA.…”

Isothermal and nonisothermal crystallization kinetics of poly(ϵ‐caprolactone)

“…To control the rate of crystallization (s 1/2 ) and the degree of crystallinity and obtain materials with better physical properties, a great deal of effort has been devoted to studying crystallization kinetics with the help of various mathematical models and determining the change in material properties. 4 The crystallization behavior 4,5 and kinetics of polymeric materials have been reviewed previously. [6][7][8] In particular, the isothermal and nonisothermal crystallization kinetics of commodity and engineering polymers, such as isotactic polypropylene, [9][10][11][12] filled polypropylenes, 13,14 poly(ethylene terephthalate), 15,16 poly(trimethylene terephthalate), 17,18 poly(butylenes terephthalate), 19 nylon, [20][21][22] and poly(sulfides), [23][24][25] have been investigated in detail, and to much lesser extent, those of biopolymers, such as poly(lactic acid) [26][27][28][29] and poly(e-caprolactone) (PCL), [30][31][32][33] have been studied, although they have found wide commercial importance.…”

Nonisothermal crystallization kinetics of poly(butylene terephthalate)/epoxidized ethylene propylene diene rubber/glass fiber composites

“…Moreover, other effects such as the slow secondary crystallization and the folded chain length are also not considered in the Ozawa model . These factors have made the quasi‐isothermal nature of Ozawa treatment somewhat questionable in the analyses of nonisothermal crystallization kinetics of PBT and its composites .…”