Studies of caprolactam and cyclic oligomer content, molecular weight, and thermal properties during melt post-polycondensation of polycaprolactam in the film state

被引：6

作者：

Zhong, Shuimi ^{[1
,2
]}

Guo, Yintao ^{[1
,2
]}

Gao, Feng ^{[1
,2
]}

Lin, Qisong ^{[1
,2
]}

Wang, Yongjun ^{[1
,2
]}

Chen, Wenxing ^{[1
,2
]}

Lu, Wangyang ^{[1
,2
]}

机构：

[1] Zhejiang Sci Tech Univ, Natl Engn Lab Text Fiber Mat & Proc Technol Zhejia, Hangzhou 310018, Peoples R China

[2] Zhejiang Prov Innovat Ctr Adv Text Technol, Shaoxing 312000, Peoples R China

来源：

POLYMER | 2023年 / 272卷

关键词：

Polycaprolactam; Cyclic oligomer; Melt post-polycondensation; PERFORMANCE LIQUID-CHROMATOGRAPHY; EPSILON-CAPROLACTAM; MASS-SPECTROMETRY; POLYAMIDE; 6; BEHAVIOR; POLYMERIZATION; CRYSTALLIZATION; ELECTROSPRAY; POLYESTERS; STABILITY;

D O I：

10.1016/j.polymer.2023.125802

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

In industrial application of polycaprolactam, the content of caprolactam monomer and oligomers, as well as their average molecular weight are the key factors. In this work, a liquid-chromatography/time-of-flight mass spec-trometry (LC-TOF-MS) method and an advanced polymer chromatography/multi-angle laser light scattering/ refractive index detector (APC-MALLS-RID) hyphenated technique have been developed as a quantitative analysis method for monomer and cyclic oligomers, and a means of determining the molecular weight of pol-ycaprolactam. The melt post-polycondensation reaction characteristics of polycaprolactam films and the varia-tion in monomers and cyclic oligomers (C2-C7) content have been systematically investigated. The results showed excellent repeatability and stability of quantitative test results on monomers and cyclic oligomers in polycaprolactam. The content of monomers and cyclic oligomers in the polycaprolactam decreased from 10.21% to 1.52% at 260 degrees C and 50 Pa for 60 min, and the average molecular weight increased from 1.53 x 104 g/mol to 2.36 x 104 g/mol. Additionally, the results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) experiments showed that the thermal stability and crystallization properties of polycaprolactam were improved after the film melt post-polycondensation reaction. Thus, this melt post-polycondensation method can realize the efficient removal of monomers and cyclic oligomers (compared with the traditional hot water extraction method) and afford high-quality polycaprolactam with high average molecular weight.

引用

页数：9