Citation: . STRUCTURAL CHARACTERIZATION OF POLYETHYLENES BY DSC ANALYSIS AFTER CRYSTALLIZATION SEGREGATION*[J]. Chinese Journal of Polymer Science, ;2000, 18(6): 557-564. shu

STRUCTURAL CHARACTERIZATION OF POLYETHYLENES BY DSC ANALYSIS AFTER CRYSTALLIZATION SEGREGATION*

Received Date: 22 March 2000

The molecular structure of polyethylene (PE) samples with various comonomers including propylene, 1-buteneand 1-hexene was investigated by DSC and 13C-NMR techniques. The density of the samples varies from 0.948 g/cm3 to0.917 g/cm3, and the molecular weight determined by the GPC method is in the range of 1～2×105. The branch point contentof the samples was determined by 13C-NMR measurements and was found to be less than 20 per 1000 C atoms along themain chain. Crystallization segregation DSC technique(CSDSC) was used to characterize the branch point distribution or the segment length distribution of PEs.The crystallization segregation was performed in a successive annealing process at decreasing temperatures.The interval of two successive annealing temperatures was 6 K,and the time length of each annealing step was 2.5h.The CSDSC results clearly indicate that all the PE samples used,including some metallocene PEs,more or less exhibit their non-uniformity in segment length distribution,and bimodal or multimodal CSDSC curves were usually observed.For quantitative characterization of the CSDSC curves and the segment length distribution two parameters,the average melting point,TmAV,and the root-mean-square deviation of melting temperature,(△Tm2 AV)1/2 were proposed.TmAV is corresponding to the average segment length due to branching and(△Tm2 AV)1/2 gives information about the width of the segment length distribution.Experimental results show that both the degree of average melting temperature depression and the width of the distribution seem of increase with increasing the branching content and are dependent on the type of comonomers.Very good reproducibility and additivity of the CSDSC method were evidenced experimentally.It was concluded that the CSDSC technique is a sensitive and convenient method for characterizing the segment length distribution of branched polyethylenes and will be of great interest in structure-property relationship studies of crystalline polymers.
1. [1]
  Maitri Bhattacharjee , Rekha Boruah Smriti , R. N. Dutta Purkayastha , Waldemar Maniukiewicz , Shubhamoy Chowdhury , Debasish Maiti , Tamanna Akhtar . Synthesis, structural characterization, bio-activity, and density functional theory calculation on Cu(Ⅱ) complexes with hydrazone-based Schiff base ligands. Chinese Journal of Inorganic Chemistry, 2024, 40(7): 1409-1422. doi: 10.11862/CJIC.20240007
2. [2]
  Jun Lu , Jinrui Yan , Yaohao Guo , Junjie Qiu , Shuangliang Zhao , Bo Bao . Controlling solid form and crystal habit of triphenylmethanol by antisolvent crystallization in a microfluidic device. Chinese Chemical Letters, 2024, 35(4): 108876-. doi: 10.1016/j.cclet.2023.108876
3. [3]
  Xin Li , Zhen Xu , Donglei Bu , Jinming Cai , Huamei Chen , Qi Chen , Ting Chen , Fang Cheng , Lifeng Chi , Wenjie Dong , Zhenchao Dong , Shixuan Du , Qitang Fan , Xing Fan , Qiang Fu , Song Gao , Jing Guo , Weijun Guo , Yang He , Shimin Hou , Ying Jiang , Huihui Kong , Baojun Li , Dengyuan Li , Jie Li , Qing Li , Ruoning Li , Shuying Li , Yuxuan Lin , Mengxi Liu , Peinian Liu , Yanyan Liu , Jingtao Lü , Chuanxu Ma , Haoyang Pan , JinLiang Pan , Minghu Pan , Xiaohui Qiu , Ziyong Shen , Qiang Sun , Shijing Tan , Bing Wang , Dong Wang , Li Wang , Lili Wang , Tao Wang , Xiang Wang , Xingyue Wang , Xueyan Wang , Yansong Wang , Yu Wang , Kai Wu , Wei Xu , Na Xue , Linghao Yan , Fan Yang , Zhiyong Yang , Chi Zhang , Xue Zhang , Yang Zhang , Yao Zhang , Xiong Zhou , Junfa Zhu , Yajie Zhang , Feixue Gao , Li Wang . Recent progress on surface chemistry Ⅱ: Property and characterization. Chinese Chemical Letters, 2025, 36(1): 110100-. doi: 10.1016/j.cclet.2024.110100
4. [4]
  Yarui Li , Huangjie Lu , Yingzhe Du , Jie Qiu , Peng Lin , Jian Lin . Highly efficient separation of high-valent actinide ions from lanthanides via fractional crystallization. Chinese Journal of Structural Chemistry, 2025, 44(4): 100562-100562. doi: 10.1016/j.cjsc.2025.100562
5. [5]
  Xueling Yu , Lixing Fu , Tong Wang , Zhixin Liu , Na Niu , Ligang Chen . Multivariate chemical analysis: From sensors to sensor arrays. Chinese Chemical Letters, 2024, 35(7): 109167-. doi: 10.1016/j.cclet.2023.109167
6. [6]
  Zhao Li , Huimin Yang , Wenjing Cheng , Lin Tian . Recent progress of in situ/operando characterization techniques for electrocatalytic energy conversion reaction. Chinese Chemical Letters, 2024, 35(9): 109237-. doi: 10.1016/j.cclet.2023.109237
7. [7]
  Teng-Yu Huang , Junliang Sun , De-Xian Wang , Qi-Qiang Wang . Recent progress in chiral zeolites: Structure, synthesis, characterization and applications. Chinese Chemical Letters, 2024, 35(12): 109758-. doi: 10.1016/j.cclet.2024.109758
8. [8]
  Neng Shi , Haonan Jia , Jixiang Zhang , Pengyu Lu , Chenglong Cai , Yixin Zhang , Liqiang Zhang , Nongyue He , Weiran Zhu , Yan Cai , Zhangqi Feng , Ting Wang . Accurate expression of neck motion signal by piezoelectric sensor data analysis. Chinese Chemical Letters, 2024, 35(9): 109302-. doi: 10.1016/j.cclet.2023.109302
9. [9]
  Yuxin Li , Chengbin Liu , Qiuju Li , Shun Mao . Fluorescence analysis of antibiotics and antibiotic-resistance genes in the environment: A mini review. Chinese Chemical Letters, 2024, 35(10): 109541-. doi: 10.1016/j.cclet.2024.109541
10. [10]
  Yin-Hang Chai , Li-Long Dang . New structural breakthrough and topological transformation of homogeneous metalla[4]catenane compounds. Chinese Journal of Structural Chemistry, 2024, 43(10): 100322-100322. doi: 10.1016/j.cjsc.2024.100322
11. [11]
  Yinghui Xia , Yixi Lin , Zhenming Xu . Cation potential guiding structural regulation of lithium halide superionic conductors. Chinese Journal of Structural Chemistry, 2025, 44(3): 100448-100448. doi: 10.1016/j.cjsc.2024.100448
12. [12]
  Guan-Nan Xing , Di-Ye Wei , Hua Zhang , Zhong-Qun Tian , Jian-Feng Li . Pd-based nanocatalysts for oxygen reduction reaction: Preparation, performance, and in-situ characterization. Chinese Journal of Structural Chemistry, 2023, 42(11): 100021-100021. doi: 10.1016/j.cjsc.2023.100021
13. [13]
  Peipei CUI , Xin LI , Yilin CHEN , Zhilin CHENG , Feiyan GAO , Xu GUO , Wenning YAN , Yuchen DENG . Transition metal coordination polymers with flexible dicarboxylate ligand: Synthesis, characterization, and photoluminescence property. Chinese Journal of Inorganic Chemistry, 2024, 40(11): 2221-2231. doi: 10.11862/CJIC.20240234
14. [14]
  Ming-Zhen Li , Yang Zhang , Kun Li , Ya-Nan Shang , Yi-Zhen Zhang , Yu-Jiao Kan , Zhi-Yang Jiao , Yu-Yuan Han , Xiao-Qiang Cao . In situ regeneration of catalyst for Fenton-like degradation by photogenerated electron transportation: Characterization, performance and mechanism comparison. Chinese Chemical Letters, 2025, 36(1): 109885-. doi: 10.1016/j.cclet.2024.109885
15. [15]
  Chun-Yun Ding , Ru-Yuan Zhang , Yu-Wu Zhong , Jiannian Yao . Binary and heterostructured microplates of iridium and ruthenium complexes: Preparation, characterization, and thermo-responsive emission. Chinese Journal of Structural Chemistry, 2024, 43(10): 100393-100393. doi: 10.1016/j.cjsc.2024.100393
16. [16]
  Tian Feng , Yun-Ling Gao , Di Hu , Ke-Yu Yuan , Shu-Yi Gu , Yao-Hua Gu , Si-Yu Yu , Jun Xiong , Yu-Qi Feng , Jie Wang , Bi-Feng Yuan . Chronic sleep deprivation induces alterations in DNA and RNA modifications by liquid chromatography-mass spectrometry analysis. Chinese Chemical Letters, 2024, 35(8): 109259-. doi: 10.1016/j.cclet.2023.109259
17. [17]
  Cheng Guo , Xiaoxiao Zhang , Xiujuan Hong , Yiqiu Hu , Lingna Mao , Kezhi Jiang . Graphene as adsorbent for highly efficient extraction of modified nucleosides in urine prior to liquid chromatography-tandem mass spectrometry analysis. Chinese Chemical Letters, 2024, 35(4): 108867-. doi: 10.1016/j.cclet.2023.108867
18. [18]
  Keqiang Shi , Xiujuan Hong , Dongyan Xu , Tao Pan , Huiwen Wang , Hongru Feng , Cheng Guo , Yuanjiang Pan . Analysis of RNA modifications in peripheral white blood cells from breast cancer patients by mass spectrometry. Chinese Chemical Letters, 2025, 36(3): 110079-. doi: 10.1016/j.cclet.2024.110079
19. [19]
  Xueqi Zhang , Han Gao , Jianan Xu , Min Zhou . Polyelectrolyte-functionalized carbon nanocones enable rapid and accurate analysis of Ag nanoparticle colloids. Chinese Chemical Letters, 2025, 36(4): 110148-. doi: 10.1016/j.cclet.2024.110148
20. [20]
  Zhaodong WANG . In situ synthesis, crystal structure, and magnetic characterization of a trinuclear copper complex based on a multi-substituted imidazo[1,5-a]pyrazine scaffold. Chinese Journal of Inorganic Chemistry, 2025, 41(3): 597-604. doi: 10.11862/CJIC.20240268

Get Citation

PDF

XML

Metrics

PDF Downloads(0)
Abstract views(565)
HTML views(20)

通讯作者: 陈斌, bchen63@163.com

1.
沈阳化工大学材料科学与工程学院沈阳 110142