Zhi-feng Cai, Qing-yin Wang, Shao-ying Liu, Gong-ying Wang. Study of KF/Al2O3 Catalyst in Synthesis of Poly(ethylene terephthalate) by Esterification. [J]. Acta Polymerica Sinica 0(9):1184-1193(2018)
DOI:
Zhi-feng Cai, Qing-yin Wang, Shao-ying Liu, Gong-ying Wang. Study of KF/Al2O3 Catalyst in Synthesis of Poly(ethylene terephthalate) by Esterification. [J]. Acta Polymerica Sinica 0(9):1184-1193(2018) DOI: 10.11777/j.issn1000-3304.2018.18014.
Study of KF/Al2O3 Catalyst in Synthesis of Poly(ethylene terephthalate) by Esterification
solid base catalysts were prepared by a wet impregnation method and applied to the synthesis of poly(ethylene terephthalate) (PET) from 1
4-dicarboxybenzene and ethylene glycol. The effect of KF content and calcination temperature on the structure
active components and properties of the catalysts were investigated. The structure of KF/Al
2
O
3
catalysts was characterized by X-ray diffraction (XRD)
scanning electron microscopy (SEM) and BET. The basic strength and basicity of KF/Al
2
O
3
catalysts were measured by Hammett indicator. The relationship between KF content
calcination temperature and the structure
basic strength and basicity of KF/Al
2
O
3
catalyst was investigated. The relationship between the structure
basic strength and basicity of KF/Al
2
O
3
catalysts and the catalytic activity in PET synthesis was also studied. The results showed that KF/Al
2
O
3
catalysts could be used to synthesize high-molecular-weight PET. It was found that several types of basic centers such as K
3
AlF
6
KAlO
2
K
2
O and K
2
CO
3
existed in the catalyst. The specific surface area of KF/Al
2
O
3
was reduced with increasing KF content. The particle size of KF/Al
2
O
3
increased with increasing KF content. The basic strength and basicity of KF/Al
2
O
3
increased with increasing KF content and calcination temperature. The activity of KF/Al
2
O
3
was related to the basic strength and basicity and was not really influenced by the specific surface area and particle size. Medium strength basic sites were responsible for the higher intrinsic viscosity
and strong basic sites could cause decomposition of the obtained polymer. Strong basic sites were mainly due to potassium carbonate
potassium aluminate and potassium oxide. The catalytic effect of 25-KF/Al
2
O
3
-400 was better than that of Sb
2
O
3
. It contained
γ
-Al
2
O
3
K
3
AlF
6
and a small amount of K
2
CO
3
. It had moderate basic strength
basicity and high activity. Based on the obtained results
the possible active site was K
3
AlF
6
. The intrinsic viscosity of 1.07 dL/g
with carboxyl end group content of 20.29 mol/t
DEG content of 2.85%
L
value of 86.6 and
b
value of 4.6
was obtained with 0.1 wt% of catalyst concentration.
关键词
KF/Al2O3碱度与碱量构效关系聚对苯二甲酸乙二醇酯
Keywords
KF/Al2O3Basic strength and basicityStructure-activity relationshipPoly(ethylene terephthalate)
references
Zhang Guoyao(张国耀), Yi Guozhen(易国祯), Wu Liheng(吴立衡), Xu Xiang(徐翔), Song Qing(宋青), Yang Yu(杨宇), Jin Jian(金剑), Zhong Shufang(钟淑芳), Qi Zongneng(漆宗能) . 高分子学报 , 1999 . ( 3 ): 309 - 314.
Ni L L, Xin J Y, Dong H X, Liu X M, Liu X M, Zhang S J . ChemSusChem , 2017 . 10 2394 - 2401.
Chen Lin(陈琳), Wu Jianing(吴嘉宁), Ni Yanpeng(倪延朋), Fu Teng(付腾), Wu Zhizheng(吴志正), Wang Xiuli(汪秀丽), Wang Yuzhong(王玉忠) . 高分子学报 , 2017 . ( 7 ): 1207 - 1214.
Aharoni S M . Polym Eng Sci , 1998 . ( 38 ): 1039 - 1047.
He M C, Yang J R . Sci Total Environ , 1999 . 234 ( 9 ): 149 - 155.
McClelland E, Harrogate. US patent, C08g, 3965071.1976-06-22
Ronald A. Tershansy. US patent, C08g, 3907754.1975-09-23
Neidel U, Eckert T . Chem Fibers Int , 1999 . 49 27 - 29.
Yin M, Li C C, Guan G H, Zhang D, Xiao Y N . J Appl Polym Sci , 2010 . 115 ( 4 ): 2470 - 2478.