摘要
为分析商用聚对苯二甲酸乙二醇酯(PET)短纤维低聚物析出的主要原因,筛选低聚物脱落性能差别显著的2种短纤维进行溶剂萃取和热诱导,制得萃取纤维、热诱导纤维和低聚物,基于其外观形貌、热性能和结晶结构等测试,分析低聚物结构组分及其析出规律与原理。结果表明:2种萃取低聚物的主要成分均为环状三聚体(C 3)和少量PET微晶聚合物,表面低聚物较多的PET短纤维(HM)含有可能是环状四聚体(C 4)的高熔点低聚物;HM低聚物的C 3和PET微晶的熔点相对较高,分别为173.5和146.7℃;C 3在短纤维、萃取低聚物和高温过程分别主要以A、B和A/B混合型晶型存在,HM低聚物的A和B型C 3的熔点相对较高,分别为173.5和314.5℃;2种纤维的低聚物含量相近,与表面低聚物较少的PET短纤维(LM)相比,HM短纤维的结晶度相对偏低11.25%,其A型C 3含量相对偏少,熔点偏高1.7℃,B型C 3的熔点偏高1.9℃,且含二甘醇残基的环聚物含量相对略高;对2种纤维在140~200℃进行热空气热诱导1 h发现,在140、160和180℃时,低聚物析出量均随温度升高而增加,但HM短纤维析出明显较少,在200℃时低聚物析出量均快速增多,晶型和数量均趋于一致;热诱导作用是影响低聚物析出的主要因素,纤维后加工的热处理条件、纤维结晶度和聚合过程中乙二醇/对苯二甲酸的质量比可能是析出的重要因素。
Objective With the development of fine denier and high-speed spinning technology,the phenomenon of oligomers migration and powders shedding from the surface of polyethylene terephthalate(PET)fiber became more and more serious,which would greatly impact on the production efficiency,quality and workers′health during the spinning and dyeing processes.It is necessary to solve the problem by exploring the migration mechanism and the structure-activity relationships of oligomers during staple fiber processing,and thus adjust the production conditions to prevent the migration.Method Two types of commercial PET staple fibers with obvious difference in white powder shedding properties were extracted and thermal induced to obtain extractive fibers,thermally induced fibers and oligomers,respectively.The thermal induction temperature was determined on the practical process of the post-spinning process.Scanning electron microscopy,differential scanning calorimetry(DSC),ultraviolet-visible spectrophotometry and X-ray diffractomety(XRD)techniques were carried out to analyze the structural constituent,precipitate law and precipitate mechanism of the oligomers.Results The main componentsof the oligomers derived from these two fibers were both cyclic trimers(C 3)and a small amount of PET microcrystalline polymers(PET microlite).The fibers which shed more powders(HM)detected few oligomers with high melting point should be assigned to the C 4 polymers.The C 3 oligomers and PET microlites were of relatively high melting temperature at 173.5 and 146.7℃,respectively,and the melting temperature for C 4 was around 274.6℃.While the C 3 and PET microlites for the fibers which shed less powders(LM)have low melting temperature around 171.8℃and 139.0℃,respectively.The C 3 in PET staple fiber,solvent extraction substance and pyroprocess existed as A type,B type and A/B mischcrystal type,respectively.The melting temperature of A type C 3 and B type C 3 from HM polymers were 173.5 and 314.5℃while the A type C 3 and B type C 3 from HM polymers were relatively lower,at 171.8 and 312.6℃,respectively.The HM and LM fibers showed similar oligomers mass ratio as 1.37%and 1.42%.Compared with the no shedding PET fiber,the shedding powder fibers contained significantly higher amount of oligomers and the crystallinity was 57.73%(11.25%lower).Moreover,the HM fibers maintained relatively small amount of A type trimer whose melting point was 1.7℃higher,and B type trimer was about 1.9℃higher,and relatively higher amount of cyclic polymers containing diethylene glycol residues.It is found that when the two fibers were subjected to thermal induction in hot air from 140 to 200℃for 1h,the oligomers migrated from the two of fibers possesses point-like crysta at 140,160 and 180℃,and the amount of oligomers increased with the rise of temperature,on the other hand,the low powder shedding fibers migrated less oligomers.When the induction temperature reached 200℃,the oligomers migrated from the surface of these two fibers were mainly multi-sided crystal type,the amount of precipitation increased rapidly compared with that at 140-180℃,and the crystal type and quantity tended to be the same quantity.Conclusion The powders shedding phenomenon during staple fiber processing has no corresponding relationship with the mass ratio of total oligomers,however,it holds a positive relationship with the quantity of oligomers migrated on the fiber surface,and thermal induction is an important factor affecting the migration of PET staple fiber oligomers.Fibers heat treatment process in post-processing,the crystallinity of the fibers,and the mass ratio of ethylene glycol to terephthalic acid during polymerization may be the influencing factors affecting the powder shedding properties of oligomers.The temperature during fibers post-processing,cooling craft and the mass ratio of ethylene glycol in polymerization could be effective methods to prevent fibers from shedding powders.
作者
谢艳霞
张唯强
徐亚宁
赵书涵
尹雯萱
张文强
韩旭
XIE Yanxia;ZHANG Weiqiang;XU Yaning;ZHAO Shuhan;YIN Wenxuan;ZHANG Wenqiang;HAN Xu(School of Textiles and Garments,Anhui Polytechnic University,Wuhu,Anhui 241000,China;Research Center of Textile Engineering Technology of Anhui Province,Wuhu,Anhui 241000,China;Chuzhou Seeker Solution Dyed Co.,Ltd.,Chuzhou,Anhui 239000,China)
出处
《纺织学报》
EI
CAS
CSCD
北大核心
2024年第1期65-73,共9页
Journal of Textile Research
基金
“纺织面料”安徽省高校重点实验室/安徽省纺织工程技术研究中心联合开放基金项目(2018AKLTF13)
安徽省科学技术厅重点研究与开发计划面上攻关项目(202004a05020053)
芜湖市科学技术局科技成果转化项目(2022cg18)。
作者简介
第一作者:谢艳霞(1971-),女,正高级工程师,博士。主要研究方向为功能性复合材料及纺织品的基础研究与应用;通信作者:韩旭(1989-),男,讲师,博士。主要研究方向为超细纤维的功能化改性。E-mail:hanxu@ahpu.edu.cn。
