摘要
由ε-CL单体催化开环聚合的聚己内酯(PCL)力学和生物相容性良好,广泛用于医疗领域。与生物降解处理方法相对比,对废弃的PCL塑料进行催化解聚回收ε-CL单体和对其进行开环再聚合的策略,可减少碳排放量,并充分利用这种高值的生物降解塑料。本论文考察了五种不同催化剂对PCL化学解聚效率和产物的影响规律,发现以异辛酸亚锡能高效催化PCL化学解聚。继而深入考察异辛酸亚锡含量、温度和反应时间等参数对PCL热解聚行为的调控机理,采用液相色谱、MS和NMR等方法分析解聚产物的组成,通过热重分析表征其解聚活化能影响因素,阐述高选择性催化解聚PCL为ε-CL单体机理,并获得ε-CL单体回收率超过91%的实验参数。对解聚回收的ε-CL单体进行开环聚合制备PCL,采用^(1)H NMR,GPC,DMA、DSC、XRD和拉伸实验等分析方法对产物结构与性能进行表征,实验结果发现回收再聚合的PCL分子量、拉伸强度和断裂延展率分别超过50 Kda,20 MPa和800%,与PCL原料相当,具有再次使用的价值。
Polycaprolactone(PCL) fabricated by catalyzed ring-opening polymerization from ε-CL monomer possesses good mechanical and biocompatible performance and is widely utilized in the medical field.Differed with the traditional biodegradation treatments,the new strategy of catalytic depolymerization of waste PCL plastics to recover ε-CL monomers and their ring-opening re-polymerization,can reduce carbon emissions and make full use of this high-value biodegradable plastic.In this study,the effects of five different catalysts on the efficiency and products of PCL from chemical depolymerization were investigated,and the results demonstrated that stannous isooctanoate achieved the best chemical depolymerization for PCL when both the catalyzed efficiently and selectivity were considered.Then,we investigated the regulation mechanism of PCL thermal depolymerization by varying the parameters of stannous isooctanoate content,temperature and reaction time.Meanwhile,the composition of the depolymerization products were characterized by liquid chromatography,MS and NMR,respectively.Moreover,the activation energy of depolymerization were evaluated by thermogravimetric analysis to explore the mechanism of the highly selective catalytic depolymerization of PCL to ε-CL monomer.Interestingly,by the optimized reaction parameters,the recovery rate of ε-CL monomer was more than 91%.Furthermore,PCL was prepared by ring-opening polymerization of ε-CL monomer recovered from depolymerization,and the structure and properties of the product were characterized by ~1 H NMR,GPC,DMA,DSC,XRD,and tensile test,respectively.The results showed that the molecular weight,tensile strength,and the elongation at break of the recycled PCL were more than 50 Kda,20 MPa,and 800%,respectively,which were comparable to those of the raw material of PCL.Strikingly,the stannous octanoate can simultaneously achieve recycled ε-CL monomer with highly efficient and selective thermal depolymerization of PCL and the re-polymerized PCL from the recycled ε-CL monomer p
作者
梁秀竹
汤栋霖
张水洞
LIANG Xiu-zhu;TANG Dong-lin;ZHANG Shui-dong(College of Mechanical and Automotive,South China University of Technology,Guangzhou 510640,China;School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,China)
出处
《化学研究与应用》
CAS
北大核心
2024年第3期640-646,共7页
Chemical Research and Application
基金
国家重点研发计划项目(2021YFB3801903)资助。
关键词
聚己内酯
异辛酸亚锡
催化解聚
高选择性
闭环回收
polycaprolactone
stannous isooctanoate
catalytic depolymerization
high selectivity
closed-loop recovery
