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]
  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
3. [3]
  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
4. [4]
  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
5. [5]
  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
6. [6]
  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
7. [7]
  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
8. [8]
  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
9. [9]
  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
10. [10]
  Xianping Du , Ying Huang , Chen Chen , Zhenhe Feng , Meng Zong . Encapsulating Si particles in multiple carbon shells with pore-rich for constructing free-standing anodes of lithium storage. Chinese Chemical Letters, 2024, 35(12): 109990-. doi: 10.1016/j.cclet.2024.109990
11. [11]
  Yu-Hui Zhang , Ye Tian , Xianliang Sheng , Chen-Shuang Liu , Lu-Qiang Wei , Jie Wang , Yong Chen . Construction of a black phosphorous-based noncovalent multiple nanosupramolecular assembly for synergistic targeted photothermal and chemodynamic therapy. Chinese Chemical Letters, 2025, 36(4): 110193-. doi: 10.1016/j.cclet.2024.110193
12. [12]
  Shunyu Wang , Yanan Zhu , Yang Zhao , Wanli Nie , Hong Meng . Steric effects and electronic manipulation of multiple donors on S₀/S₁ transition of D_n-A emitters. Chinese Chemical Letters, 2025, 36(4): 110555-. doi: 10.1016/j.cclet.2024.110555
13. [13]
  Tong Su , Yue Wang , Qizhen Zhu , Mengyao Xu , Ning Qiao , Bin Xu . Multiple conductive network for KTi₂(PO₄)₃ anode based on MXene as a binder for high-performance potassium storage. Chinese Chemical Letters, 2024, 35(8): 109191-. doi: 10.1016/j.cclet.2023.109191
14. [14]
  Yi Cao , Xiaojiao Ge , Yuanyuan Wei , Lulu He , Aiguo Wu , Juan Li . Tumor microenvironment-activatable neuropeptide-drug conjugates enhanced tumor penetration and inhibition via multiple delivery pathways and calcium deposition. Chinese Chemical Letters, 2024, 35(4): 108672-. doi: 10.1016/j.cclet.2023.108672
15. [15]
  Shimei Wu , Yining Li , Lantao Chen , Yufei Zhang , Lingxing Zeng , Haosen Fan . Hexapod cobalt phosphosulfide nanorods encapsulating into multiple hetero-atom doped carbon frameworks for advanced sodium/potassium ion battery anodes. Chinese Chemical Letters, 2025, 36(4): 109796-. doi: 10.1016/j.cclet.2024.109796
16. [16]
  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
17. [17]
  Tingting Liu , Pengfei Sun , Wei Zhao , Yingshuang Li , Lujun Cheng , Jiahai Fan , Xiaohui Bi , Xiaoping Dong . Magnesium doping to improve the light to heat conversion of OMS-2 for formaldehyde oxidation under visible light irradiation. Chinese Chemical Letters, 2024, 35(4): 108813-. doi: 10.1016/j.cclet.2023.108813
18. [18]
  Lian Sun , Honglei Wang , Ming Ma , Tingting Cao , Leilei Zhang , Xingui Zhou . Shape and composition evolution of Pt and Pt₃M nanocrystals under HCl chemical etching. Chinese Chemical Letters, 2024, 35(9): 109188-. doi: 10.1016/j.cclet.2023.109188
19. [19]
  Rong-Nan Yi , Wei-Min He . Electron donor-acceptor complex enabled arylation of dithiocarbamate anions with thianthrenium salts under aqueous micellar conditions. Chinese Chemical Letters, 2024, 35(11): 110194-. doi: 10.1016/j.cclet.2024.110194
20. [20]
  Yan-Kai Zhang , Yong-Zheng Zhang , Chun-Xiao Jia , Fang Wang , Xiuling Zhang , Yuhang Wu , Zhongmin Liu , Hui Hu , Da-Shuai Zhang , Longlong Geng , Jing Xu , Hongliang Huang . A stable Zn-MOF with anthracene-based linker for Cr(VI) photocatalytic reduction under sunlight irradiation. Chinese Chemical Letters, 2024, 35(12): 109756-. doi: 10.1016/j.cclet.2024.109756

Get Citation

PDF

XML

Metrics

PDF Downloads(0)
Abstract views(508)
HTML views(8)

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