【摘 要】
：
In this paper, we proposed a method to determine the nucleation effect of pre-existing crystals on crystallization of the second block in double crystalline blo
【机 构】
：
Department of Polymer Science & Engineering
论文部分内容阅读
In this paper, we proposed a method to determine the nucleation effect of pre-existing crystals on crystallization of the second block in double crystalline block copolymers, which is usually covered by the suppression effect. The nucleation mechanism of poly(ethylene oxide) (PEO) block from the pre-crystallized polyethylene (PE) block in poly(ethylene-co-butene)-b-poly(ethylene glycol) (EmEOn) dibloek copolymers was investigated under variable crystallization environments.The crystallization environment for the PEO block was altered by cooling at different cooling rates or successive selfnucleation (SSN) to the PE block. It was found that the presence of nucleation effect is strongly dependent on composition of the block copolymers. The crystallization temperature (Tc) of PEO block in E174EO90 increases as cooling rate applied to the PE block decreases, indicating that PE block can nucleate the crystallization of PEO block and more perfect PE crystals have stronger nucleation effect. In E182EO41 crystallization of the PEO block is confined, shown by the disappearance of selfnucleation domain, and the PE block has no nucleation effect on the crystallization of PEO block. Double crystallization peaks are observed for the PEO block in E182EO41 and the intensity of the crystallization peak at higher temperature increases as the PE crystals become more perfect. After exclusion of homogeneous nucleation mechanism, the higher temperature crystallization peak of the PEO block in E182EO41 is tentatively ascribed to surface nucleation.
其他文献
In a novel method for synthesizing ultrafine aluminum hydroxide particles presented in this paper, the morphology and crystal structure of the particles were in
In this paper, a new kind of symmetry and its conserved quantities of a mechanical system in phase space are studied. The definition of this new symmetry, i.e.,
For many processes of industrial significance, due to the strong coupling between particle interactions and fluid dynamics, the population balance must be solve
The cell adhesive motif RGD tripeptide was synthesized by using a novel chemical method. First, Gly-Asp(GD)was synthesized in two steps including the chloroacet
The reaction of 3-nitro-4-chlorobenzenesulfinic acid and ethylene oxide to obtain 2-nitro-4-(β-hydroxyethylsulfonyl)chlorobenzene had been studied. Except hydr
We show that high photon-number squeezing in bright light can be generated in both lasers and optical bistabilities by the injections of a squeezed vacuum and a
Silver nanoparticles with average particles sizes ranging from 2 to 131nm were manipulatively synthesized starting from silver nitrate using different functiona
Laser shock forming (LSF) was a new technique realized by applying an impulsive pressure generated by laser-induced shock wave on the surface of metal sheet. LS
(E) -2-(1H-Benzo [d][1,2,3]triazol-1-yl) -3- (4-chlorophenyl) -3-hydroxy-N-phenylprop-2-enethioamide (compound 1) and ( E ) -2- ( 1H-benzo [ d ] [ 1,2,3 ] triaz
A method of estimating the safe storage life (τ), self-accelerating decomposition temperature (TSADT) and critical temperature of thermal explosion (Tb) of dou