The structure of aggregation state and isothermal crystallization behavior of Nylon-1010 have been studied by WAXD,DSE,Variance-Range Function and density measurement.The results show that crystallization of Nylon-101...The structure of aggregation state and isothermal crystallization behavior of Nylon-1010 have been studied by WAXD,DSE,Variance-Range Function and density measurement.The results show that crystallization of Nylon-1010 has the most suitable annealing temperature,the crystals of the Nxlon-1010 are two-dimension heterogeneous nucleation.Both low treatment temperature and high crystallization te,temperature are disadvantageous for Nylon-1010 crystal growth.展开更多
In this study, the isothermal crystallization kinetics and crystalline morphology of poly（butylene adipate-co-butylene 1,4-cyclohexanedicarboxylate）（PBAC）, which refers to a copolyester containing a non-planar rin...In this study, the isothermal crystallization kinetics and crystalline morphology of poly（butylene adipate-co-butylene 1,4-cyclohexanedicarboxylate）（PBAC）, which refers to a copolyester containing a non-planar ring structure, were investigated by differential scanning calorimetry and polarized optical microscopy, and compared with those of neat poly（butylene 1,4-cyclohexanedicarboxylate）（PBC）. The results indicate that the introduction of butylene adipate（BA） unit into PBAC did not change the intrinsical crystallization mechanism. But, the crystallization rate and ability, and equilibrium melting temperature of PBAC copolymers were reduced. All PBC and PBAC copolymers could only form high density of nucleation from melt at given supercooling, while no Maltese cross or ring-banded spherulites could be observed. PBAC copolymers with a high amount of BA unit became amorphous after quenching with liquid nitrogen from melt, while PBC and PBAC copolymers with a low amount of BA unit could still form a large amount of nuclei under the same treatment.展开更多
Differential fast scanning calorimetry（DFSC） was employed on the study of self-nucleation behavior of poly（butylene succinate）（PBS）.The ultra-fast cooling ability of DFSC allows investigating the effect of self-...Differential fast scanning calorimetry（DFSC） was employed on the study of self-nucleation behavior of poly（butylene succinate）（PBS）.The ultra-fast cooling ability of DFSC allows investigating the effect of self-nucleation on the isothermal crystallization kinetics over a wide temperature range.Crystallization half-time,instead of crystallization peak temperature,was used to describe the self-nucleation behavior,and the self-nucleation domain for the samples crystallized at different temperatures was determined.Due to the competition between homogenous nucleation and self-nuclei,the effect of self-nucleation was less pronounced at high supercooling than that for the sample isothermally crystallized at higher temperature.An efficiency scale to judge the efficiency of nucleating agents from the crystallization half-time was also introduced in this work.展开更多
文摘The structure of aggregation state and isothermal crystallization behavior of Nylon-1010 have been studied by WAXD,DSE,Variance-Range Function and density measurement.The results show that crystallization of Nylon-1010 has the most suitable annealing temperature,the crystals of the Nxlon-1010 are two-dimension heterogeneous nucleation.Both low treatment temperature and high crystallization te,temperature are disadvantageous for Nylon-1010 crystal growth.
基金financially supported by the National Natural Science Foundation of China(No.51503217)Zhejiang Province Public Welfare Project(No.2017C31081)+1 种基金the Open Project Program of MOE Key Laboratory of Macromolecular Synthesis and Functionalization,Zhejiang University(No.2016MSF001)Youth Innovation Promotion Association CAS(No.2017339)
文摘In this study, the isothermal crystallization kinetics and crystalline morphology of poly（butylene adipate-co-butylene 1,4-cyclohexanedicarboxylate）（PBAC）, which refers to a copolyester containing a non-planar ring structure, were investigated by differential scanning calorimetry and polarized optical microscopy, and compared with those of neat poly（butylene 1,4-cyclohexanedicarboxylate）（PBC）. The results indicate that the introduction of butylene adipate（BA） unit into PBAC did not change the intrinsical crystallization mechanism. But, the crystallization rate and ability, and equilibrium melting temperature of PBAC copolymers were reduced. All PBC and PBAC copolymers could only form high density of nucleation from melt at given supercooling, while no Maltese cross or ring-banded spherulites could be observed. PBAC copolymers with a high amount of BA unit became amorphous after quenching with liquid nitrogen from melt, while PBC and PBAC copolymers with a low amount of BA unit could still form a large amount of nuclei under the same treatment.
基金financially supported by the National Natural Science Foundation of China(Nos.21474049,51673094 and 21404055)the Shenzhen Science and Technology Innovation Committee(Nos.JCYJ20160531151102203 and JCYJ20160608140827794)Tianshan Scholars Program by Yili Normal University
文摘Differential fast scanning calorimetry（DFSC） was employed on the study of self-nucleation behavior of poly（butylene succinate）（PBS）.The ultra-fast cooling ability of DFSC allows investigating the effect of self-nucleation on the isothermal crystallization kinetics over a wide temperature range.Crystallization half-time,instead of crystallization peak temperature,was used to describe the self-nucleation behavior,and the self-nucleation domain for the samples crystallized at different temperatures was determined.Due to the competition between homogenous nucleation and self-nuclei,the effect of self-nucleation was less pronounced at high supercooling than that for the sample isothermally crystallized at higher temperature.An efficiency scale to judge the efficiency of nucleating agents from the crystallization half-time was also introduced in this work.
