Citation: WANG Dexi, R. E. Lyon, R. J. Farris. MULTIPLE MELTING TRANSITIONS IN POLYURETHANE-UREA ELASTOMERS UNDER EXTENSION[J]. Chinese Journal of Polymer Science, ;1986, 4(3): 274-283. shu

MULTIPLE MELTING TRANSITIONS IN POLYURETHANE-UREA ELASTOMERS UNDER EXTENSION

Received Date: 2 March 1986

Two melting transitions were observed in linear segmented polyurethane-urea elastomers underextension using thermal, mechanical and X-ray diffraction techniques, and the results are compared.These data indicate both strain-induced and temperature-induced crystallization in the stretchedclastomers, which may result from two different types of crystallites with different melting tempera-tures. These have been assigned as type 1 appearing around 60℃, and type 2 around 30℃. The type 1 crystallization can be induced by stretching at room temperature to large strain,and is mechanically reversible,but the type 2 crystallization is mainly induced by cooling below its crystallization temperature.These two crystalline structures are interchangeable under suitable conditions.At elongations greater than 300%,the low temperature peak observed on fusion thermograms disappears or combines with the high temperature peak.When the temperature of the samplc is over the melting point of the type 1 crystal,irreversible melting occurs and only the type 2 crystal develops on cooling.The results of stress-strain and stress hysteresis experiments at different temperatures indicate the relative importance of strain-induced and temperature-induced crystallization on the mechanical properties of these materials.
1. [1]
  Tao Tang , Chen Li , Sipu Li , Zhong Qiu , Tianqi Yang , Beirong Ye , Shaojun Shi , Chunyang Wu , Feng Cao , Xinhui Xia , Minghua Chen , Xinqi Liang , Xinping He , Xin Liu , Yongqi Zhang . One-step constructing advanced N-doped carbon@metal nitride as ultra-stable electrocatalysts via urea plasma under room temperature. Chinese Chemical Letters, 2024, 35(11): 109887-. doi: 10.1016/j.cclet.2024.109887
2. [2]
  Xiafeng Yang , Wushan Sun , Chen Li , Wei Bai , Qingyin Wang , Gongying Wang . Synthesis of novel isosorbide-based polycarbonates by melt chain extension method. Chinese Chemical Letters, 2026, 37(4): 111674-. doi: 10.1016/j.cclet.2025.111674
3. [3]
  Shifang Song , Chenyu Wu , Li Zhang , Dezhi Yang , Yang Lu , Zhengzheng Zhou . Unpacking phase transitions in multi-component drug systems: A case study. Chinese Chemical Letters, 2025, 36(7): 110911-. doi: 10.1016/j.cclet.2025.110911
4. [4]
  Fangzhou Wang , Wentong Gao , Chenghui Li . A weak but inert hindered urethane bond for high-performance dynamic polyurethane polymers. Chinese Chemical Letters, 2024, 35(5): 109305-. doi: 10.1016/j.cclet.2023.109305
5. [5]
  Jiaxiang Guo , Zeyi Li , Tianyu Zhang , Xinyu Tian , Yue Wang , Chuandong Dou . Thienothiophene-centered ladder-type π-systems that feature distinct quinoidal π-extension. Chinese Chemical Letters, 2024, 35(5): 109337-. doi: 10.1016/j.cclet.2023.109337
6. [6]
  Jaeheon Lee , Jung Hyeun Kim . Effect of thermal annealing on cold crystallization ability of thermoset polyurethane elastomer synthesized from fully bio-derived polyol. Chinese Journal of Structural Chemistry, 2025, 44(5): 100568-100568. doi: 10.1016/j.cjsc.2025.100568
7. [7]
  Shengyu Zhao , Qinhao Shi , Wuliang Feng , Yang Liu , Xinxin Yang , Xingli Zou , Xionggang Lu , Yufeng Zhao . Suppression of multistep phase transitions of O3-type cathode for sodium-ion batteries. Chinese Chemical Letters, 2024, 35(5): 108606-. doi: 10.1016/j.cclet.2023.108606
8. [8]
  Chao Jia , Min Ren , Yingdi Jin , Xingxing Li . Hydrogen migration induced magnetic phase transitions in two-dimensional Fe-porphyrinoid metal-organic frameworks. Chinese Journal of Structural Chemistry, 2026, 45(2): 100801-100801. doi: 10.1016/j.cjsc.2025.100801
9. [9]
  Shengkai Li , Yuqin Zou , Chen Chen , Shuangyin Wang , Zhao-Qing Liu . Defect engineered electrocatalysts for C–N coupling reactions toward urea synthesis. Chinese Chemical Letters, 2024, 35(8): 109147-. doi: 10.1016/j.cclet.2023.109147
10. [10]
  Shuyuan Pan , Zehui Yang , Fang Luo . Ni-based electrocatalysts for urea assisted water splitting. Chinese Journal of Structural Chemistry, 2024, 43(8): 100373-100373. doi: 10.1016/j.cjsc.2024.100373
11. [11]
  Yanhui Zhong , Peisi Xie , Chengyi Xie , Lei Guo , Weiwei Chen , Shuyi Wang , Xiaoxiao Wang , Fuyue Wang , Zian Lin , Gongke Li , Zongwei Cai . Rigid urea-based structures drive analysis of chiral amino acids. Chinese Chemical Letters, 2026, 37(2): 112039-. doi: 10.1016/j.cclet.2025.112039
12. [12]
  Yongwei Qian , Shengyang Huang , Yaoyi Su , Songna Zhang , Yang Liu , Ming Liu , Bin Sun , Hao Li . A conformationally adaptive cage with multiple guest recognition modes. Chinese Chemical Letters, 2026, 37(4): 111354-. doi: 10.1016/j.cclet.2025.111354
13. [13]
  Ying Xu , Chengying Shen , Hailong Yuan , Wei Wu . Mapping multiple phases in curcumin binary solid dispersions by fluorescence contrasting. Chinese Chemical Letters, 2024, 35(9): 109324-. doi: 10.1016/j.cclet.2023.109324
14. [14]
  Yue Zhang , Xiaoya Fan , Xun He , Tingyu Yan , Yongchao Yao , Dongdong Zheng , Jingxiang Zhao , Qinghai Cai , Qian Liu , Luming Li , Wei Chu , Shengjun Sun , Xuping Sun . Ambient electrosynthesis of urea from carbon dioxide and nitrate over Mo₂C nanosheet. Chinese Chemical Letters, 2024, 35(8): 109806-. doi: 10.1016/j.cclet.2024.109806
15. [15]
  Rui Deng , Wenjie Jiang , Tianqi Yu , Jiali Lu , Boyao Feng , Panagiotis Tsiakaras , Shibin Yin . Cycad-leaf-like crystalline-amorphous heterostructures for efficient urea oxidation-assisted water splitting. Chinese Journal of Structural Chemistry, 2024, 43(7): 100290-100290. doi: 10.1016/j.cjsc.2024.100290
16. [16]
  Wenjie Jiang , Zhixiang Zhai , Xiaoyan Zhuo , Jia Wu , Boyao Feng , Tianqi Yu , Huan Wen , Shibin Yin . Revealing the reactant adsorption role of high-valence WO3 for boosting urea-assisted water splitting. Chinese Journal of Structural Chemistry, 2025, 44(3): 100519-100519. doi: 10.1016/j.cjsc.2025.100519
17. [17]
  Liang-Yu Chang , Li-Ju Xu , Dong Qiu . Shellac-based capsule for long-term controlled releasing urea with a broad soil pH tolerance. Chinese Chemical Letters, 2025, 36(5): 110034-. doi: 10.1016/j.cclet.2024.110034
18. [18]
  Qimeng Zhu , Juan Xiao , Changyi Deng , Tingting Huang , Hui Ding , Li Zhang , Guancheng Xu . Highly active transition metal phosphides for urea oxidation: Design strategies, application advances, and perspectives. Chinese Journal of Structural Chemistry, 2025, 44(9): 100651-100651. doi: 10.1016/j.cjsc.2025.100651
19. [19]
  Hongyang Li , Yue Liu , Xiuwen Wang , Haijing Yan , Guimin Wang , Dongxu Wang , Yilong Wang , Shuo Yang , Yanqing Jiao . Morphology engineering and electronic structure remodeling of manganese-incorporated VN for boosting urea-assisted energy-saving hydrogen production. Chinese Chemical Letters, 2025, 36(6): 110042-. doi: 10.1016/j.cclet.2024.110042
20. [20]
  Feibin Wei , Yongfang Rao , Yu Huang , Wei Wang , Hui Mei . The new challenges for the development of NH₃-SCR catalysts under new situation of energy transition in power generation industry. Chinese Chemical Letters, 2024, 35(6): 108931-. doi: 10.1016/j.cclet.2023.108931

Get Citation

PDF

XML

Metrics

PDF Downloads(0)
Abstract views(1300)
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

Address：Zhongguancun North First Street 2,100190 Beijing, PR China Tel: +86-010-82449177-888

DownLoad: Full-Size Img PowerPoint

Return