Synthesis and improved mechanical properties of twin-mesogenic epoxy thermosets using siloxane spacers with different lengths

被引:16
作者
Harada, Miyuki [1 ]
Hirotani, Mio [1 ]
Ochi, Mitsukazu [1 ]
机构
[1] Kansai Univ, Fac Chem Mat & Bioengn, 3-3-35 Yamate Cho, Suita, Osaka 5648680, Japan
关键词
epoxy resin; liquid crystal; mesogenic group; siloxane; toughness; LIQUID-CRYSTALLINE EPOXY; ELASTOMER-MODIFIED EPOXIES; TOUGHENING MECHANISMS; THERMAL-CONDUCTIVITY; FRACTURE MECHANISM; AZOMETHINE MESOGEN; BONDING PROPERTIES; DIGLYCIDYL ETHER; CROSS-LINKING; RESIN;
D O I
10.1002/app.47891
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
A series of twin-mesogenic epoxy resins with siloxane (di-, tri-, and tetra-siloxane) chain spacers of different lengths were successfully synthesized. Results showed that the melting point of the twin-mesogenic epoxy monomers decrease by more than 50 degrees C due to the change of siloxane spacer length. In particular, the tri- and tetra-incorporated siloxane twin-mesogenic epoxy monomers showed a liquid crystalline (LC) phase below 100 degrees C during the cooling process. Epoxy thermosets with isotropic and smectic (S-m) LC phases were then prepared using an aromatic amine and the dependence on curing temperature was investigated. Furthermore, the relationship between the ordered network chain structure and mechanical properties was investigated. Results were compared with isotropic and S-m LC phases. The tensile strain and fracture energy in the S-m type LC thermosets increased without a decrease in the tensile modulus, and this occurred in all systems irrespective of siloxane spacer length. The maximum value of the fracture energy (283 kJ m(-2)) reached by LC thermosets with increased spacer lengths was twice as large as that using the alkyl chain spacer (144 kJ m(-2)). (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47891.
引用
收藏
页数:10
相关论文
共 58 条
  • [41] Synthesis of a novel siloxane-containing diamine for increasing flexibility of epoxy resins
    Park, SJ
    Jin, FL
    Park, JH
    Kim, KS
    [J]. MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, 2005, 399 (1-2): : 377 - 381
  • [42] TOUGHENING MECHANISMS IN ELASTOMER-MODIFIED EPOXIES .2. MICROSCOPY STUDIES
    PEARSON, RA
    YEE, AF
    [J]. JOURNAL OF MATERIALS SCIENCE, 1986, 21 (07) : 2475 - 2488
  • [43] INFLUENCE OF PARTICLE-SIZE AND PARTICLE-SIZE DISTRIBUTION ON TOUGHENING MECHANISMS IN RUBBER-MODIFIED EPOXIES
    PEARSON, RA
    YEE, AF
    [J]. JOURNAL OF MATERIALS SCIENCE, 1991, 26 (14) : 3828 - 3844
  • [44] Investigation of anisotropic epoxy-amine thermosets synthesised in a magnetic field
    Pottie, Laurence
    Costa-Torro, France
    Tessier, Martine
    Davidson, Patrick
    Fradet, Alain
    [J]. LIQUID CRYSTALS, 2008, 35 (08) : 913 - 924
  • [45] Poly(azomethine-ester-siloxane)s:: Synthesis and thermal behaviour
    Racles, C
    Cozan, V
    Cazacu, M
    Földes, E
    Sajo, I
    [J]. HIGH PERFORMANCE POLYMERS, 2002, 14 (04) : 397 - 413
  • [46] Ribera D, 2001, MACROMOL CHEM PHYS, V202, P1658, DOI 10.1002/1521-3935(20010601)202:9<1658::AID-MACP1658>3.0.CO
  • [47] 2-0
  • [48] Ribera D., 2002, J POLYM SCI A, V40, P316
  • [49] Rochow E.G., 1946, Introduction to the Chemistry of the Silicones
  • [50] Shiota A, 1996, J POLYM SCI POL CHEM, V34, P1291, DOI 10.1002/(SICI)1099-0518(199605)34:7<1291::AID-POLA16>3.0.CO