The composition and sequence distribution of monomeric units in polyester polyether multiblock copolymer were studied by pyrolysis? gas chromatography (PGC) and pyrolysis gas chromatography/mass spectrometry (PGC/M...The composition and sequence distribution of monomeric units in polyester polyether multiblock copolymer were studied by pyrolysis? gas chromatography (PGC) and pyrolysis gas chromatography/mass spectrometry (PGC/MS). PGC was applied to study the F t curve of the multiblock copolymer and PGC/MS was used to separate and identify the pyrolyzates. DTA experiment was used to study the decomposition temperature. The results show that the beginning point of elastomer’s decomposition was about 300?℃ and the decomposition temperature of most of the sample was 550?℃. Many pyrolyzates were produced because of the breaking of weak bonds in the sample. The possible microstructure was verified and the pyrolysis pathway of the copolymer was investigated.展开更多
The influence of zeolite structure and process parameters(including reaction temperature and catalyst/oil ratio)on rules for formation of ethylene and propylene in the course of catalytic pyrolysis of n-heptane was st...The influence of zeolite structure and process parameters(including reaction temperature and catalyst/oil ratio)on rules for formation of ethylene and propylene in the course of catalytic pyrolysis of n-heptane was studied in a small-scale fixed fluid catalytic cracking unit.Test results have revealed that compared to the USY zeolite and Beta zeolite,the catalytic pyrolysis of n-heptane in the presence of the ZRP zeolite catalyst can result in higher yield and selectivity of ethyl-ene and propylene,while a higher reaction temperature and a higher catalyst/oil ratio can promote the formation of ethylene and propylene during catalytic pyrolysis of n-heptane.The ethylene formation reaction is more sensitive to the changes in reaction temperature,whereas the changes in catalyst/oil ratio are more influential to the propylene formation reaction.This paper has made a preliminary exploration into the different reaction pathways for formation of ethylene and propylene on zeolites with different structures.展开更多
文摘The composition and sequence distribution of monomeric units in polyester polyether multiblock copolymer were studied by pyrolysis? gas chromatography (PGC) and pyrolysis gas chromatography/mass spectrometry (PGC/MS). PGC was applied to study the F t curve of the multiblock copolymer and PGC/MS was used to separate and identify the pyrolyzates. DTA experiment was used to study the decomposition temperature. The results show that the beginning point of elastomer’s decomposition was about 300?℃ and the decomposition temperature of most of the sample was 550?℃. Many pyrolyzates were produced because of the breaking of weak bonds in the sample. The possible microstructure was verified and the pyrolysis pathway of the copolymer was investigated.
文摘The influence of zeolite structure and process parameters(including reaction temperature and catalyst/oil ratio)on rules for formation of ethylene and propylene in the course of catalytic pyrolysis of n-heptane was studied in a small-scale fixed fluid catalytic cracking unit.Test results have revealed that compared to the USY zeolite and Beta zeolite,the catalytic pyrolysis of n-heptane in the presence of the ZRP zeolite catalyst can result in higher yield and selectivity of ethyl-ene and propylene,while a higher reaction temperature and a higher catalyst/oil ratio can promote the formation of ethylene and propylene during catalytic pyrolysis of n-heptane.The ethylene formation reaction is more sensitive to the changes in reaction temperature,whereas the changes in catalyst/oil ratio are more influential to the propylene formation reaction.This paper has made a preliminary exploration into the different reaction pathways for formation of ethylene and propylene on zeolites with different structures.
