ที่มา:วิทยาสารเกษตรศาสตร์ สาขา วิทยาศาสตร์

หัวเรื่อง:ไม่มีชื่อไทย (ชื่ออังกฤษ : Non-Isothermal Crystallization and Thermal Degradation Kinetics of Biodegradable Poly(butylene adipate-co-terephthalate)/Starch Blends)

ผู้เขียน:ดร.สุรศักดิ์ เชียงกา, รองศาสตราจารย์, Satayu Suwannasopon, Nutnarun (Supreya) Trivijitkasem

สื่อสิ่งพิมพ์:pdf

Abstract

The non-isothermal crystallization behavior of biodegradable poly (butylene adipate-coterephthalate)/ starch (PBAT/S) blends was studied using differential scanning calorimetry under a nitrogen atmosphere from 25 to 225 ?C at four constant cooling rates of 5, 10, 15 and 20 ?C.min-1. There was only one crystallization peak in the exothermic curve which shifted to a lower temperature as the cooling rate was increased. The crystallization temperature decreased from 98 to 84 ?C, but the crystallization enthalpy increased from 11 to 12 J.g-1 as the heating rate was increased. The thermal degradation(TG) of the PBAT/S blends was studied using thermogravimetric analysis under a nitrogen atmosphere from 100 to 800 ?C at five constant heating rates of 1, 2, 5, 10, and 15 ?C.min-1. The TG curves showed two degradation stages occurring at 309–342 ?C and 375–420 ?C, which were the degradation of corn starch and PBAT, respectively. The thermal degradation kinetics of the PBAT/S were analyzed using the isoconversion Flynn- Wall-Ozawa model-free method. The results showed that both the apparent activation energy and the logarithm pre-exponent factor increased with increasing conversion ?. The average apparent activation energy and the average logarithm apparent pre-exponent factor for ? = 0.1 – 0.9 were 266 kJ.mol-1 and 37 min-1, respectively. The reaction model g(?) determined from the master plot method for PBAT/S was a phase-boundary controlled reaction, where g(?) = [1– (1– ?)1/2]

Article Info

Agriculture and Natural Resources -- formerly Kasetsart Journal (Natural Science), Volume 047, Issue 5, Sep 13 - Oct 13, Page 781 - 789 |  PDF |  Page