Fracture Energies and Related Microstructure of SBS and SBS/PS Blends

• Main Authors: Lin Mu Chun, 林睦群
• Other Authors: Chi Wang
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/58580959672738556132

碩士 === 元智大學 === 化學工程研究所 === 88 === ABSTRACT The objective of this study is to investigate fracture energies and related morphology of two systems. The first is specimens of neat styrene-butadiene-styrene (SBS) block copolymers and the second is SBS/polystyrene (PS) blends. The neat SBS specimens were prepared from three different methods; SBSI specimens were cast from toluene solution, SBSII specimens were prepared from compression molding and SBS III specimens were prepared from compression molding after processing in a brabender internal mixer. The specimens of SBS/PS blends with different PS contents were prepared using a brabender internal mixer as well. Fracture energies of all the specimens were measured using a trouser tear test. The glass transition temperatures and tand of PB and PS segments were measured by thermal and dynamic mechanical analyses. The average network strand molecular weight, Mc, were determined by the Flory-Rehner equation from equilibrium swelling using isooctane as a diluent. The microstructure were studied using transmission electron microscopy (TEM) and small-angle X-ray scattering (SAXS). For the neat SBS specimens, SBSI possesses the lowest fracture energies because of morphology with less continuous PS domain and more regular microstructure. The fracture energies of SBSIII were smaller than SBSII due to a smaller value of Mc . For the specimens of SBS/PS blends, SBS/PS=100/44 specimens possess the largest fracture energies than the others. (Keywords: SBS/PS blend; fracture energy; morphology).