PET/PEG共聚酯连续熔融终缩聚过程两相稳态模型分析

doi:10.11949/0438-1157.20220621

摘要/Abstract

摘要：

针对高性能共聚酯PET/PEG缩聚过程，建立了圆盘反应器中连续熔融聚合两相稳态模型，模拟分析了缩聚反应温度、压力、停留时间以及传质系数对气相组成、共聚酯数均分子量、端羧基浓度以及副产物二甘醇和水浓度的影响。结果表明：挥发组分主要在反应器的前半部分产生，在z > 0.4后气相挥发总量已经很小；乙二醇占气相组成的比例极高，约为90%，而二甘醇的含量极低，只为0.5%左右；随反应器温度、真空度、停留时间、传质系数的增加，共聚酯产物的分子量增大，当传质系数大于0.1 s^-1后，反应器出口的共聚酯分子量几乎不再变化，此时已不受传质控制，最终产物的分子量约26000。

关键词: PET/PEG共聚酯, 熔融共聚, 两相模型, 稳态分析

Abstract:

For the high-performance copolyester PET/PEG polycondensation process, a two-phase steady-state model of continuous melt polymerization in a disk reactor was established. The effects of reaction temperature, pressure, residence time and mass transfer parameters on the vapor phase composition, the number average molecular weight, by-product concentration and carboxyl end group concentration were analyzed. The results showed that the volatile components were mainly produced in the first half of the reactor. After z > 0.4, the total amount of volatile had been very small. The proportion of ethylene glycol to the vapor phase was very high, about 90%, while the content of diethylene glycol was very low, only about 0.5%. The molecular weight of copolymer increased with the increase of reactor temperature, vacuum degree, residence time and mass transfer coefficient, when the mass transfer coefficient was greater than 0.1 s^-1, the molecular weight of the copolyester at the reactor outlet almost did not change. At this time, it was no longer controlled by mass transfer, and the molecular weight of the final product could reach about 26000.

Key words: PET/PEG copolymer, melt copolycondensation, two-phase model, steady-state analysis

中图分类号:

TQ 323.4⁺1

张雅曼, 邢玉林, 蒋杰, 赵玲, 奚桢浩. PET/PEG共聚酯连续熔融终缩聚过程两相稳态模型分析[J]. 化工学报, 2022, 73(10): 4722-4733.

Yaman ZHANG, Yulin XING, Jie JIANG, Ling ZHAO, Zhenhao XI. Two-phase model for continuous final stage melt copolycondensation of PET/PEG copolymer in steady-state analysis[J]. CIESC Journal, 2022, 73(10): 4722-4733.

图/表 10

表1 PET/PEG共缩聚反应过程中所涉及的化合物及其官能团

Table 1 Compounds and functional groups involved in PET/PEG synthesis

Molecular/ functional group	Symbol	Molecular structure
ethylene glycol	EG	HO—CH₂—CH₂—OH
diethylene glycol	DEG	HO—CH₂—CH₂—O—CH₂—CH₂—OH
acetaldehyde	AA
water	W	H₂O
EG end group	tEG	R₁—O—CH₂—CH₂—OH
EG repeat unit	bEG	R₁—O—CH₂—CH₂—O—R₂
TPA end group	tTPA
TPA repeat unit	bTPA
DEG end group	tDEG	R₁—CH₂—CH₂—O—CH₂—CH₂—OH
DEG repeat unit	bDEG	R₁—CH₂—CH₂—O—CH₂—CH₂—R₂
poly(ethylene glycol)	PEG
PEG end group	tPEG
PEG repeat unit	bPEG
vinyl end group	tV

表2 动力学参数

Table 2 Kinetic parameters

k_i,K_i	A_i	E_i / (kJ·mol^-1)	ΔS_i / (J·mol^-1·K^-1)	ΔH_i / (kJ·mol^-1)
k₁/(kg·mol^-1·min^-1)	1.04×10⁶	73.64
k₂/(kg·mol^-1·min^-1)	6.78×10⁵	65.79
k₃/(kg·mol^-1·min^-1)	1.04×10⁶	73.64
k₄/(kg·mol^-1·min^-1)	3.39×10⁵	65.79
k₅/(kg·mol^-1·min^-1)	6.8×10⁵	77.40
k₆/(kg·mol^-1·min^-1)	7.80×10⁴	55.18
k₇/min^-1	4.16×10⁷	124.68
k₈/(kg·mol^-1·min^-1)	4.16×10⁷	124.68
k₉/(kg·mol^-1·min^-1)	4.16×10⁷	124.68
k₁₀/min^-1	3.60×10⁹	158.16
k₁₁/(kg·mol^-1·min^-1)	6.80×10⁵	77.40
K₄			87.8	-44.9
K₆			-184.4	94.0

图1 连续熔融终缩聚过程的两相模型示意图

Fig.1 Two-phase model for continuous melt polymerization

图2 传质浓度与挥发组分沿管长的变化关系

Fig.2 Variation of mass transfer and volatile components along tube length

图3 不同反应器操作条件对气相摩尔分数的影响

Fig.3 Effect of reactor operating conditions on vapor-phase composition

图4 不同反应器操作条件对Mn的影响

Fig.4 Effect of reactor operating conditions on Mn

图5 传质参数对反应器出口Mn的影响

Fig.5 Effect of mass-transfer coefficient on Mn at reactor outlet

图6 不同反应器操作条件对熔体中DEG浓度的影响

Fig.6 Effect of reactor operating conditions on the concentration of DEG in melt phase

图7 不同反应器操作条件对熔体中水浓度的影响

Fig.7 Effect of reactor operating conditions on the concentration of W in melt phase

图8 不同反应器操作条件对端羧基浓度的影响

Fig.8 Effect of reactor operating conditions on the concentration of acid end group

参考文献 35

1	陆晓中, 季常青, 梁玉增, 等. PET/PEG共聚酯及共混物的抗静电性能研究[J]. 现代塑料加工应用, 1999, 11(3): 1-4.
	Lu X Z, Ji C Q, Liang Y Z, et al. Study on the antistatic PET-PEG copolymers and PET/PEG blends[J]. Modern Plastics Processing and Applications, 1999, 11(3): 1-4.
2	陆嘉, 王兴仁, 凌泽济, 等. PET-PEG共聚酯性能的研究[J]. 合成技术及应用, 1999, 14(1): 21-24.
	Lu J, Wang X R, Ling Z J, et al. Study on properties of PET-PEG copolyester[J]. Synthetic Technology and Application, 1999, 14(1): 21-24.
3	刘云鸿, 李光吉, 陈超, 等. 超疏水PET织物的制备及其抗菌性能[J]. 化工学报, 2014, 65(4): 1517-1525.
	Liu Y H, Li G J, Chen C, et al. Preparation and antibacterial activity of superhydrophobic PET fabric[J]. CIESC Journal, 2014, 65(4): 1517-1525.
4	钱伯章. 我国PET生产现状[J]. 聚酯工业, 2017, 30(1): 5-7, 10.
	Qian B Z. Production status of PET in China[J]. Polyester Industry, 2017, 30(1): 5-7, 10.
5	周华堂, 许贤文, 舒伟. 国内外聚酯产业链发展及趋势[J]. 纺织导报, 2017, 12: 60-62.
	Zhou H T, Xu X W, Shu W. Developing trends of polyester industry at home and abroad[J]. China Textile Leader, 2017, 12: 60-62.
6	吴剑南. 我国聚酯工业现状和前景展望[J]. 当代石油石化, 2004, 12(6): 16-19, 49.
	Wu J N. The status of China's polyester industry and its propect[J]. Petrochemical Industry Trends, 2004, 12(6): 16-19, 49.
7	Wang Y, Tang J G, Zheng H J, et al. Crystallization of poly(ethylene terephthalate) via silica nanoparticles tethered with short diblock PEG-PET copolymers[J]. Science of Advanced Materials, 2016, 8(8): 1603-1611.
8	Kim S, Bowen R A R, Zare R N. Transforming plastic surfaces with electrophilic backbones from hydrophobic to hydrophilic[J]. ACS Applied Materials & Interfaces, 2015, 7(3): 1925-1931.
9	赵彩霞, 柏祥, 邹国享, 等. AA/PTA单体比例对PBAT共聚酯性能的影响[J]. 化工学报, 2017, 68(1): 452-459.
	Zhao C X, Bai X, Zou G X, et al. Effect of monomer ratio of AA/PTA on properties of PBAT copolyesters[J]. CIESC Journal, 2017, 68(1): 452-459.
10	夏峰伟, 戴志彬. 新戊二醇共聚改性PET热性能研究[J]. 合成技术及应用, 2012, 27(2): 7-10.
	Xia F W, Dai Z B. Thermal properties of PET modified by neopentyl glycol[J]. Synthetic Technology & Application, 2012, 27(2): 7-10.
11	李鑫, 刘润涛, 顾利霞. 共聚酯PEIT-PEG结构与性能的研究[J]. 功能高分子学报, 2003, 16(2): 214-218.
	Li X, Liu R T, Gu L X. Study on the structure and properties of poly(ethylene terephthalate-co-isophthalate)-poly(ethylene glycol) (PEIT-PEG) copolyester[J]. Journal of Functional Polymers, 2003, 16(2): 214-218.
12	方孝芬. 新型亲水阻燃聚酯纤维的制备及性能研究[D]. 上海: 东华大学, 2014.
	Fang X F. Synthesis and properties study on the novel hydrophilic and flame retardant polyester fiber [D]. Shanghai: Donghua University, 2014.
13	Schmidbauer S, Ladurner R, Hallfeldt K K, et al. Heavy-weight versus low-weight poly-propylene meshes for open sublay mesh repair of incisional hernia.[J]. European Journal of Medical Research, 2005, 10(6): 247-253.
14	Sepehri S, Rafizadeh M, Afshar-Taromi F. Synthesis and characterization of copolymers of poly(ethylene terephthalate) and cyclohexane dimethanol in a semibatch reactor (including the process model)[J]. Journal of Applied Polymer Science, 2009, 113(6): 3520-3532.
15	Wang H Y, Feng Y K, Fang Z C, et al. Co-electrospun blends of PU and PEG as potential biocompatible scaffolds for small-diameter vascular tissue engineering[J]. Materials Science and Engineering: C, 2012, 32(8): 2306-2315.
16	You D Q, Liang H, Mai W Z, et al. Microwave-assisted functionalization of polyurethane surface for improving blood compatibility[J]. Journal of Industrial and Engineering Chemistry, 2013, 19(5): 1587-1592.
17	周光宇, 胡吉, 朱美芳, 等. PET-PEG共聚物相变性能的研究[J]. 合成纤维, 2005, 34(3): 1-4, 11.
	Zhou G Y, Hu J, Zhu M F, et al. Study on the phase-change properties of PET-PEG copolymers[J]. Synthetic Fiber in China, 2005, 34(3): 1-4, 11.
18	陆晓中, 孙晓民, 王和平, 等. PET/PEG共聚反应的动力学研究[J]. 聚酯工业, 2004, 17(1): 19-22.
	Lu X Z, Sun X M, Wang H P, et al. The reaction kinetics of PET/PEG copolymerization[J]. Polyester Industry, 2004, 17(1): 19-22.
19	胡吉. 热储能型相变纤维的研究-嵌段共聚物(PET-PEG)相变纤维的制备及其性能的研究[D]. 上海: 东华大学, 2006.
	Hu J. Study on heat-storage phase-change fiber-copolymer(PET-PEG) phase-change fiber[D]. Shanghai: Donghua University, 2006.
20	李伟. PET/PEG共聚酯合成工艺及动力学研究[D]. 上海: 华东理工大学, 2018.
	Li W. Synthesis and copolycondensation kinetics of PET/PEG copolymer[D]. Shanghai: East China University of Science and Technology, 2018.
21	Ravindranath K, Mashelkar R A. Modeling of poly(ethylene terephthalate) reactors(part 6): A continuous process for final stages of polycondensation[J]. Polymer Engineering and Science, 1982, 22(10): 628-636.
22	Cheong S I, Choi K Y. Modeling of a continuous rotating disk polycondensation reactor for the synthesis of thermoplastic polyesters[J]. Journal of Applied Polymer Science, 1996, 61(5): 763-773.
23	Yoon K H, Park O O. Analysis of a reactor with surface renewal for poly(ethylene terephthalate) synthesis[J]. Polymer Engineering and Science, 1994, 34(3): 190-200.
24	Cheong S I, Choi K Y. Melt polycondensation of poly(ethylene terephthalate) in a rotating disk reactor[J]. Journal of Applied Polymer Science, 1995, 58(9): 1473-1483.
25	沈瀛坪, 赵玲. 聚酯(PET)反应过程研究(Ⅶ): 后缩聚反应过程研究和数学模拟[J]. 化学反应工程与工艺, 1997, 13(4): 48-53.
	Shen Y P, Zhao L. Studies on reaction process for poly ethylene terephthalate(Ⅶ): An experimental research and mathematical model for computer simulation of a continuous final stage polymerization process[J]. Chemical Reaction Engineering and Technology, 1997, 13(4): 48-53.
26	Kumar A, Gupta S K, Madan S, et al. Solution of final stages of polyethylene terephthalate reactors using orthogonal collocation technique[J]. Polymer Engineering & Science, 1984, 24(3): 194-204.
27	Murakami Y, Fujimoto K, Kakimoto S, et al. On a high viscosity polymer finisher apparatus with two agitator axes having multidisks[J]. Journal of Chemical Engineering of Japan, 1972, 5(3): 257-263.
28	Ravetkar D D, Kale D D. Gas absorption into non-Newtonian fluids in rotating disc contactors[J]. Chemical Engineering Science, 1981, 36(2): 399-403.
29	王良生, 戴干策. 圆盘反应器成膜性和持液量研究[J]. 化学反应工程与工艺, 2000, 16(2): 127-135.
	Wang L S, Dai G C. A study of film forming and hold-up in a rotating disc-ring reactor[J]. Chemical Reaction Engineering and Technology, 2000, 16(2): 127-135.
30	赵玲, 王良生, 朱中南, 等. 圆盘反应器中的PET缩聚过程[J]. 聚酯工业, 2002, 15(1): 1-5, 8.
	Zhao L, Wang L S, Zhu Z N, et al. PET polycondensation process in disc-rotating reactor[J]. Polyester Industry, 2002, 15(1): 1-5, 8.
31	Flory P. Molecular size distribution in linear condensation polymers[J]. Journal of the American Chemical Society, 1936, 58(10): 1877-1885.
32	Ravindranath K, Mashelkar R A. Modeling of poly(ethylene terephthalate) reactors(part 5): A continuous prepolymerization process[J]. Polymer Engineering and Science, 1982, 22(10): 619-627.
33	Laubriet C, LeCorre B, Choi K Y. Two-phase model for continuous final stage melt polycondensation of poly(ethylene terephthalate)(part 1): Steady-state analysis[J]. Industrial & Engineering Chemistry Research, 1991, 30(1): 2-12.
34	Kim I S, Woo B G, Choi K Y, et al. Two-phase model for continuous final-stage melt polycondensation of poly(ethylene terephthalate)(part Ⅲ): Modeling of multiple reactors with multiple reaction zones[J]. Journal of Applied Polymer Science, 2003, 90(4): 1088-1095.
35	Gupta S K, Ghosh A K, Gupta S K, et al. Analysis of wiped film reactors using the orthogonal collocation technique[J]. Journal of Applied Polymer Science, 1984, 29(11): 3217-3230.