固相缩聚扩链PET的结晶与流变性能研究
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摘要
利用固相缩聚法在不同缩聚时间制备扩链聚对苯二甲酸乙二醇酯(PET),对扩链PET的流变性能及结晶行为进行了研究。结果表明:PET粉末经过8 h的固相缩聚,特性黏度最佳为1.30 dL/g,此时扩链PET的流动性明显降低,熔体流动速率(MFR)由纯PET的81.3 g/10 min降至34.9 g/10 min。流变性能也有一定程度的变化,随着固相缩聚时间的延长,扩链PET复数黏度呈现依次升高的趋势,并且与改性前的PET相比,剪切变稀现象更明显。同时,固相缩聚后PET的结晶能力变差,产物在降温过程中甚至难以形成明显的结晶峰,结晶度从30.7%降至3.6%。
The chain-extended polyethylene terephthalate(PET) was prepared by solid state polycondensation at different polycondensation times,the rheological property and crystallization behavior of the chain-extended PET were studied. The results show that the PET powder undergoes solid state polycondensation for 8 h, and the optimum intrinsic viscosity is 1.30 dL/g, the fluidity of the chain-extended PET is significantly lowered, and the melt flow rate(MFR) is effectively reduced from 81.3 g/10 min of the pure PET to 34.9 g/10 min. The rheological properties also change to a certain extent. With the prolongation of solid state polycondensation time, the complex viscosity of chian-extended PET tends to increase in turn, and the shear thinning phenomenon is more obvious than that of unmodified PET.At the same time, the crystallization ability of PET after solid-state polycondensation is decreased, and it is difficult to form an obvious crystallization peak during the cooling process, and the crystallinity of the product reduces from 30.7% to 3.6%.
The chain-extended polyethylene terephthalate(PET) was prepared by solid state polycondensation at different polycondensation times,the rheological property and crystallization behavior of the chain-extended PET were studied. The results show that the PET powder undergoes solid state polycondensation for 8 h, and the optimum intrinsic viscosity is 1.30 dL/g, the fluidity of the chain-extended PET is significantly lowered, and the melt flow rate(MFR) is effectively reduced from 81.3 g/10 min of the pure PET to 34.9 g/10 min. The rheological properties also change to a certain extent. With the prolongation of solid state polycondensation time, the complex viscosity of chian-extended PET tends to increase in turn, and the shear thinning phenomenon is more obvious than that of unmodified PET.At the same time, the crystallization ability of PET after solid-state polycondensation is decreased, and it is difficult to form an obvious crystallization peak during the cooling process, and the crystallinity of the product reduces from 30.7% to 3.6%.
引文
[1] ZHANG Y J,ZHANG C,LI H Q,et al.Effect of cyclotrimerization of bisphenol-A dicyanate monomer on poly(ethylene terephthalate) chain extension[J].Polymer Engineering and Science,2011,51(9):1791-1796.
[2] FORSYTHE J S,CHEAH K,NISBET D R,et a1.Rheological properties of high melt strength poly(ethylene terephthalate)formed by reactive extrusion[J].Journal of Applied Polymer Science,2006,100: 3646-3652.
[3] GANTILLON B,SPITZ R,MCKENNA T E.The solid state postcondensation of PET,2-Toward the development of a new dispersed phase solid state process[J].Macromolecular Materials and Engineering,2004,289(1):106-112.
[4] 顾艺,夏艳平,曹峥,等. 化学扩链法/固相缩聚法对聚对苯二甲酸乙二醇酯的结晶与流变性能的影响[J]. 高分子材料科学与工程, 2018(1):54-59.
[2] FORSYTHE J S,CHEAH K,NISBET D R,et a1.Rheological properties of high melt strength poly(ethylene terephthalate)formed by reactive extrusion[J].Journal of Applied Polymer Science,2006,100: 3646-3652.
[3] GANTILLON B,SPITZ R,MCKENNA T E.The solid state postcondensation of PET,2-Toward the development of a new dispersed phase solid state process[J].Macromolecular Materials and Engineering,2004,289(1):106-112.
[4] 顾艺,夏艳平,曹峥,等. 化学扩链法/固相缩聚法对聚对苯二甲酸乙二醇酯的结晶与流变性能的影响[J]. 高分子材料科学与工程, 2018(1):54-59.