基于DSC-SSA鉴别低密度聚乙烯再生料

Identifi cation of Low-density Polyethylene Recycled Materials Based on DSC-SSA

采用差示扫描量热仪对不同再生料添加量低密度聚乙烯(LDPE)再生料进行熔融温度及连续自成核和退火热分级(DSC-SSA)分析,并通过分峰拟合及归一化处理对DSC-SSA分级峰进行处理。结果发现,经DSC-SSA处理后的熔融曲线相较于普通DSC熔融曲线更能表征分子内部长度不一的链段结构,基体料和再生料样品内部均含有若干不同规整度的分子链。添加了再生料的样品熔融曲线上均出现了T4和T5两个分级峰,据此可有助于鉴别LDPE再生料。此外,随再生料添加量的增加,基体料分子链的规整度整体呈下降趋势。

Differential scanning calorimeter was used to analyze the melting temperature and continuous self-nucleation and annealing heat classification(DSC-SSA)of low-density polyethylene(LDPE)recycled materials with different recycled materials,peak fitting and normalization treatment processes were applied to analysis the DSC-SSA classifi cation peaks.The results showed that the melting curve after DSC-SSA treatment can better characterize the segment structure of different molecular lengths than the ordinary DSC melting curve.Both the base material and the recycled material sample contain several molecular chains with different regularities.Two grading peaks,T4 and T5,appeared on the melting curve of the samples added with recycled materials,which can help identify LDPE recycled materials.In addition,with the increase of the amount of recycled materials added,the regularity of the molecular chain of the matrix material showed a downward trend as a whole.