Agglomeration behaviour of caprolactam solution concentrates triggered by cyclic dimers in the recovery process: Characterisation, mechanism, and process optimisation

Yi, Chunwang; Yang, Ce; Li, Jie; Chen, Juan; Zhang, Shen; Sun, Huan

doi:10.1016/j.psep.2020.01.026

Cited by 11 publications

(22 citation statements)

References 26 publications

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“…4,5 A decrease of the oligomer content in PA6 can increase the melting temperature of polymers. 1,6,7 In addition, the low content of oligomers in PET, polybutylene terephthalate (PBT), and polypropylene (PP) reduced the potential risks to the human environment triggered by the migration of oligomers. 3,8−10 However, some studies revealed that adding a certain amount of chitosan oligomers can increase the anti-cancer effect of a material.…”

Section: Introductionmentioning

confidence: 99%

Oligomer Content Determines the Properties and Application of Polycaprolactone

Gong

et al. 2022

Macromolecules

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The oligomers in polymer materials have a decisive influence on properties. However, there is a lack of studies on the oligomers in polycaprolactone (PCL), and the effect of oligomers on material performance has not yet been revealed. In this work, the oligomer content in PCL was quantitatively characterized, and the result refers that the cyclic dimer content reaches 97 wt % in the PCL oligomer. In addition, the effect of oligomers on the thermal behavior, the in vitro degradability, and the in vitro cytotoxicity cell experiments were further investigated. In the in vitro degradation simulation experiments, the PCL with a higher content of oligomers showed faster degradation than that with a lower content of oligomers. Moreover, the in vitro cytotoxicity cell experiments proved that increasing the content of oligomers can greatly improve the biocompatibility of PCL materials. These results can help researchers better understand oligomers and promote the application of PCL more directly.

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Section: Introductionmentioning

confidence: 99%

Oligomer Content Determines the Properties and Application of Polycaprolactone

Gong

et al. 2022

Macromolecules

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“…[2][3][4][5][6] The ROP of CPL is the preferred method for mass production thanks to its economical availability, polymerization stability, and competitive efficient-to-cost ratio. 7 However, although the performance of PA6 is excellent, there are still many things that can be improved. The improvement of PA6 can be achieved by adding different comonomers, polymers, or fillers for modification.…”

Section: Introductionmentioning

confidence: 99%

“…15,10,[16][17][18][19][20][21] For example, the final product of PA6 is inevitably accompanied by approximately 10 wt% of ring products or oligomers during the process of caprolactam hydrolytic polymerization, also known as extractables, which highly affected the final performance and stability of products. 7 Yi and coworkers 17 used ε-caprolactam as a solvent to copolymerized with terephthalic acid (TPA) and 1,6-hexamethylenediamine (HMDA), this copolymerization of approach endowed the PA6 copolymers with higher thermal stability, better transparency, and lower extractables concentration than neat PA6. However, regardless of which comonomers are used, the high concentration of comonomers in the PA6 system was generally negative for the thermomechanical properties and crystallization ability of the final product, 15,[22][23][24] this phenomenon has become an issue worthy of attention encountered in copolymerized modification of PA6.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and characterization of trace aromatic copolyamide 6 with tunable mechanical and viscoelastic behavior

Chen

Lee

Rwei

2021

J of Applied Polymer Sci

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terephthalamide/adipic acid (BAHT-AA) was chosen to be used as a comonomer to develop a novel polyamide 6 (PA6) with the trace-content aromatic structure. A series of polyamide 6 copolymers (coPA6) with trace BAHT-AA loading were synthesized to yield the modified copolyamides with multiple interactions of hydrogen bonding and π-π stacking on the PA6 backbone. It was proved that the thermal stability and mechanical properties of coPA6 were significantly enhanced because of the introduction of the trace BAHT-AA segment. More importantly, adding a trace (1, 2, and 4 mole%) of BAHT-AA could effectively increase the network structure and highly decrease the free volume fraction in the polymer system that is proved by the relaxation behavior and melt viscoelastic behavior. The results showed that the integrated performances of coPA6 were better than that of pure PA6, which was highly correlated with the aforementioned multiple interactions. For example, outstanding tensile strength (73.0 vs. 56.8 MPa), and modulus (1167 vs. 929 MPa), and so on. This work provided the traditional PA6 with the modification of outstanding mechanical and thermal performances, thus expanding its application for the plastics and textile industries.

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“…However, PA6 must undergo hydrothermal extraction before spinning to eliminate the water-soluble monomer and cyclic oligomers (about 8–10 wt%) after chemical equilibrium. 22,23 5-SSIPA easily precipitates out of the matrix during the hydrothermal extraction process, resulting in the loss of functionality. The current preparation of CD-PA6 fiber is mainly achieved by blending pure PA6 with cationic dyeable polyester (CD-PET).…”

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confidence: 99%

“…The carboxyl terminal structure at both ends of 5-SSIPA will inevitably destroy the molar balance between the amino group and the carboxyl group in the system, thereby producing the end-capping effect. 22 Xiong and Yin 10 introduced 5-SSIPA into PA6 by copolymerization, but the end-capping effect made its molecular weight unable to be effectively guaranteed. The obtained chips could not be processed by melt spinning, which affected its wider application.…”

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confidence: 99%

Preparing cationic dyeable polyamide 6 filaments by combining the masterbatch technique with melt copolymerization

Zhang

Yang

et al. 2021

Textile Research Journal

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Cationic dyeable polyamide 6 (CD-PA6) fiber, as a novel functional polyamide 6 (PA6) fiber, conforms to people's requirements for fashion clothing. However, due to the limitation of the hetero-end groups after caprolactam hydrolysis, it is difficult to introduce comonomers into the PA6 molecular chain to prepare PA6-based polymers with a certain molecular weight and maintain the original physical properties and spinnability. In this paper, through molecular design of PA6 segments, 5-sulfoisophthalic acid monosodium salt (5-SSIPA) was introduced into PA6 by copolymerization, and a CD-PA6 masterbatch with an addition amount of 10 wt% was prepared. CD-PA6 were prepared by blending with pure PA6 with masterbatch technology. The melt-spinning method was used to prepare CD-PA6 filaments, and they were woven into fabrics. The results show that the CD-PA6 masterbatch and PA6 have good blending compatibility. CD-PA6 filaments and fabrics maintain the excellent physical properties of PA6. When the addition amount of 5-SSIPA is 3%, the dye uptake rate of the cationic pigment exceeds 90%, and it has color affinity and excellent color fastness.

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Agglomeration behaviour of caprolactam solution concentrates triggered by cyclic dimers in the recovery process: Characterisation, mechanism, and process optimisation

Cited by 11 publications

References 26 publications

Oligomer Content Determines the Properties and Application of Polycaprolactone

Oligomer Content Determines the Properties and Application of Polycaprolactone

Synthesis and characterization of trace aromatic copolyamide 6 with tunable mechanical and viscoelastic behavior

Preparing cationic dyeable polyamide 6 filaments by combining the masterbatch technique with melt copolymerization

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