响应面法优化废旧PET催化醇解工艺
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摘要
常压下采用催化剂一步醇解废旧聚酯(PET)工艺制备聚酯多元醇,并采用物理发泡方式用该聚酯多元醇制备了硬质聚氨酯泡沫塑料,达到废旧PET的循环利用。以催化醇解得到聚酯多元醇的羟值、酸值和黏度为指标,筛选催化剂用量、醇解剂用量和醇解时间为主要因素,通过响应面法优化得到催化醇解废旧PET的最佳工艺条件,即:质量分数0.3%(占PET的质量,下同)的Sb2O3作为解聚的催化剂、质量分数100%的二甘醇为醇解剂,醇解反应时间为2.5 h,通过实验验证表明该条件可靠,实际得到的聚酯多元醇羟值503.9 mgKOH/g,酸值2.4 mgKOH/g,室温黏度1310 mPa·s,以该聚酯多元醇为原料制备硬质聚氨酯泡沫的导热系数为0.02～0.03 W/(m·K),密度为40～50 kg/m3,表明通过该方法实现废旧PET的循环利用是可行的,并提高了其循环利用价值。
Polyester polyols were prepared by an one-step depolymerization of polyethylene terephthalate(PET) using catalysts under ordinary pressure and then used as raw material to prepare rigid polyurethane foam by physical foaming method. The hydroxyl value, acid value and viscosity of polyester polyols were used as evaluation index to investigate the effects of catalyst dosage, dosage of alcoholysis agent and pyrolysis time on the alcoholysis process of PET by using response surface methodology(RSM). The optimum process conditions were obtained as follows: the mass fraction of catalyst(Sb2 O3) was 0.3%(based on the weight of PET, the same below), diethylene glycol(DEG) with a mass fraction of 100% was used as alcoholysis agent, reaction time was 2.5 h. The experimental verification indicated that the conditions by RSM analysis were reliable. The hydroxyl value, acid value and viscosity of the product were 503.9 mg KOH/g, 2.4 mg KOH/g and 1310 mPa·s, respectively. The prepared rigid polyurethane foam had coefficients of thermal conductivity of 0.02～0.03 W/(m·K) with a density between 40 kg/m3 and 50 kg/m3, indicating that this method is feasible to realize the recycling of waste PET and improve its recycling value.
Polyester polyols were prepared by an one-step depolymerization of polyethylene terephthalate(PET) using catalysts under ordinary pressure and then used as raw material to prepare rigid polyurethane foam by physical foaming method. The hydroxyl value, acid value and viscosity of polyester polyols were used as evaluation index to investigate the effects of catalyst dosage, dosage of alcoholysis agent and pyrolysis time on the alcoholysis process of PET by using response surface methodology(RSM). The optimum process conditions were obtained as follows: the mass fraction of catalyst(Sb2 O3) was 0.3%(based on the weight of PET, the same below), diethylene glycol(DEG) with a mass fraction of 100% was used as alcoholysis agent, reaction time was 2.5 h. The experimental verification indicated that the conditions by RSM analysis were reliable. The hydroxyl value, acid value and viscosity of the product were 503.9 mg KOH/g, 2.4 mg KOH/g and 1310 mPa·s, respectively. The prepared rigid polyurethane foam had coefficients of thermal conductivity of 0.02～0.03 W/(m·K) with a density between 40 kg/m3 and 50 kg/m3, indicating that this method is feasible to realize the recycling of waste PET and improve its recycling value.
引文
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[5]Liu Huaxia(刘华夏),Lu Lu(芦璐),Gao Yuanpeng(高远鹏).Alcohosis of PET waste and its application in preparation of unsaturated polyester resin[J].Materials Researsh and Application(材料研究与应用),2015,9(3):166-171.
[6]Wang Min(王敏).Determination of apigenin in marchantia convoluta[J].Technology&Development of Chemical Industry(化工技术与开发),2005,34(2):42-43.
[7]Rubén L F,Itxaso D I,Beatriz de R,et al.Kinetics of catalytic glycolysis of PET wastes with sodium carbonate[J].Chemical Engineering Journal,2011,168(2011):312-320.
[8]Saurabh C,Parthasarathy S,Devendra K,et al.Microwave assisted glycolysis of poly(ethylene terepthalate)for preparation of polyester polyols[J].Journal of Applied Polymer Science,2013,129(5):2779-2788.
[9]Liu Runqing(刘润清),Huang Jiming(黄继明),Wei Enguang(韦恩光).Optimization of Fe3O4/NiO catalyzed alcoholysis of polyethylene terephthalate by response surface methodology[J].Fine Chemicals(精细化工),2017,34(12):1390-1396.
[10]Macdonald W A.New advances in poly(ethylene terephthalate)polymerization and degradation[J].Polyer International,2002,51(10):923-930.
[11]Suo Qianqian(索倩倩).The technical study of PET glycolysis[D].Shanghai:East China University of Science and Technology,2017.
[12]Zhu Yawan(朱亚婉).Study on PET dissolution and the synthesis of modified PET copolyesters[D].Guang-zhou:South China University of Technology(华南理工大学),2014.
[13]Hu Haobin,Wu Yun,Zhu Zhiming.Optimization of microwaveassisted preparation of TPA from waste PET using response surface methodology[J].Journal of Polymers and The Environment,2017,10:1-8.
[14]Luo Xiaolan,Li Yebo.Synthesis and characterization of polyols and polyurethane foams from PET waste and crude glycerol[J].Journal of Polymer Environment,2014,22(3):318-328.
[15]Hammi K M,Jdey A,Abdelly C,et al.Optimization of ultrasound-assisted extraction of antioxidantcompounds from Tunisian Zizyphus lotusfruits using responsesurface methodology[J].Food Chem,2015,184:80-89.
[16]Determination of hydroxyl of polyester polyols(聚酯多元醇中羟值的测定方法)[S].HG/T2709-95.1995.
[17]Determination of acid of polyester polyols(聚酯多元醇中酸值的测定方法)[S].HG/T2708-95.1995.
[2]Xi Guoxi(席国喜),Li Wei(李伟),Xin Xinyan(邢新艳).New development of recycling of waste polyester[J].Chemical Industry and Engineering Progres(化工进展),2002,21(6):434.
[3]Lv Hui(吕慧),Zhen Haijian(郑海建).Polyol depolymerization waste PET optimization conditions[J].Journal of Changchun University of Technology:Natural Science Edition(长春工业大学学报:自然科学版),2014,35(1):26-29.
[4]Lu Xiaoling(卢晓玲).Study on the application of PET glycolysis products to the synthesis of polyurethane elastoer[D].Guangzhou:South China University of Technology(华南理工大学),2011.
[5]Liu Huaxia(刘华夏),Lu Lu(芦璐),Gao Yuanpeng(高远鹏).Alcohosis of PET waste and its application in preparation of unsaturated polyester resin[J].Materials Researsh and Application(材料研究与应用),2015,9(3):166-171.
[6]Wang Min(王敏).Determination of apigenin in marchantia convoluta[J].Technology&Development of Chemical Industry(化工技术与开发),2005,34(2):42-43.
[7]Rubén L F,Itxaso D I,Beatriz de R,et al.Kinetics of catalytic glycolysis of PET wastes with sodium carbonate[J].Chemical Engineering Journal,2011,168(2011):312-320.
[8]Saurabh C,Parthasarathy S,Devendra K,et al.Microwave assisted glycolysis of poly(ethylene terepthalate)for preparation of polyester polyols[J].Journal of Applied Polymer Science,2013,129(5):2779-2788.
[9]Liu Runqing(刘润清),Huang Jiming(黄继明),Wei Enguang(韦恩光).Optimization of Fe3O4/NiO catalyzed alcoholysis of polyethylene terephthalate by response surface methodology[J].Fine Chemicals(精细化工),2017,34(12):1390-1396.
[10]Macdonald W A.New advances in poly(ethylene terephthalate)polymerization and degradation[J].Polyer International,2002,51(10):923-930.
[11]Suo Qianqian(索倩倩).The technical study of PET glycolysis[D].Shanghai:East China University of Science and Technology,2017.
[12]Zhu Yawan(朱亚婉).Study on PET dissolution and the synthesis of modified PET copolyesters[D].Guang-zhou:South China University of Technology(华南理工大学),2014.
[13]Hu Haobin,Wu Yun,Zhu Zhiming.Optimization of microwaveassisted preparation of TPA from waste PET using response surface methodology[J].Journal of Polymers and The Environment,2017,10:1-8.
[14]Luo Xiaolan,Li Yebo.Synthesis and characterization of polyols and polyurethane foams from PET waste and crude glycerol[J].Journal of Polymer Environment,2014,22(3):318-328.
[15]Hammi K M,Jdey A,Abdelly C,et al.Optimization of ultrasound-assisted extraction of antioxidantcompounds from Tunisian Zizyphus lotusfruits using responsesurface methodology[J].Food Chem,2015,184:80-89.
[16]Determination of hydroxyl of polyester polyols(聚酯多元醇中羟值的测定方法)[S].HG/T2709-95.1995.
[17]Determination of acid of polyester polyols(聚酯多元醇中酸值的测定方法)[S].HG/T2708-95.1995.