In order to explore the influence of the physical crosslinking network structure of polyborosiloxanes(PBDMSs) on the viscoelasticity of the system, hydroxyl terminated polydimethylsiloxane (PDMS) with different hydroxyl contents were reacted with boric acid to prepare PBDMSs with different boronization crosslinking densities. Thereafter the structure, thermodynamics and rheological properties of the as prepared samples were characterized. The results show that PBDMSs contain Si—O—Si, Si—O—B, CH3—Si—CH3 and B—O—B structural units. And PBDMSs have excellent low temperature resistance, while their glass transition temperature increases with the increase of hydroxyl content in PDMS. And at low hydroxyl content of PDMS (1% and 2%, mass fraction), crystallization of PBDMSs are observed. Moreover, PBDMSs possess the characteristics of frequency sensitivity, good impact resistance, excellent damping dissipation and excellent resilience. The hydroxyl content of PDMS obviously affects the physical crosslinking network structure of PBDMSs, and thus has a significant impact on the dynamic modulus of PBDMSs. In practical application, the viscoelasticity of PBDMSs can be adjusted by changing the hydroxyl content of PDMS.
TANG M , WANG W T , XU D H , et al. Synthesis of structure-controlled polyborosiloxanes and investigation on their viscoelastic response to molecular mass of polydimethylsiloxane triggered by both chemical and physical interactions[J]. Industrial & Engineering Chemistry Research, 2016, 55 (49): 12582- 12589.
WU T F , CHEN B Q . Synthesis of multi-walled carbon nanotube-reinforced polyborosiloxane nanocomposites with mechanically adaptive and self-healing capabilities for flexible conductors[J]. ACS Applied Materials & Interfaces, 2016, 8 (36): 1- 8.
LIU Z , PICKEN S J , BESSELING N A M . Polyborosiloxanes (PBSs), synthetic kinetics, and characterization[J]. Macromolecules, 2014, 47 (14): 4531- 4537.
LI X F , ZHANG D , XIANG K W , et al. Synthesis of polyborosiloxane and its reversible physical cross-links[J]. RSC Advances, 2014, 4 (62): 1- 8.
陈欣. 阻尼硅橡胶的制备及性能研究[D]. 济南: 山东大学, 2017.
CHEN X. Preparation and properties of damping silicone rubber[D]. Jinan: Shandong University, 2017.
DROZDOV F V , MILENIN S A , GORODOV V V , et al. Crosslinked polymers based on polyborosiloxanes: synthesis and properties[J]. Journal of Organometallic Chemistry, 2019, 891, 72- 77.
ZHOU D , MIAO Y G , WANG Y P , et al. Response characteristics of boric acid modified hydroxyl-terminated polysiloxane-silica composites under impact loading[J]. Journal of Ordnance Engineering, 2018, 39 (1): 137- 145.
ZHOU C , WANG B , ZHANG F T , et al. Micro-gels for impact protection[J]. Journal of Applied Polymer Science, 2013, 130, 2345- 2351.
RAN G , LIU X , GUO J , et al. Improving the flame retardancy and water resistance of polylactic acid by introducing polyborosiloxane microencapsulated ammonium polyphosphate[J]. Composites Part B, 2019, 173, 106772.
ZHANG D S , JIANG N , CHEN X Y , et al. Rheology of crosslinked entangled polymers: shear stiffening in oscillatory shear[J]. Journal of Applied Polymer Science, 2020, 137 (9): 48421.
SLAWOMIR R . New facile process for synthesis of borosiloxane resins[J]. Journal of Inorganic and Organometallic Polymers and Materials, 2014, 24 (6): 1092- 1095.
KASGOZ A , KURAMATA M , MISONO T , et al. Preparation of polyborosiloxane as a precursor for borosilicate fibers[J]. Journal of the Ceramic Society of Japan, 1989, 97 (11): 1432- 1434.
WU C L , HSUECH C , HSU J S , et al. Static and dynamic mechanical properties of polydimethylsiloxane/carbon nanotube nanocomposites[J]. Thin Solid Films, 2009, 517 (17): 4895- 4901.
范伟. 聚硼硅氧烷改性硅胶与发泡聚氨酯动态力学性能研究[D]. 西安: 西安理工大学, 2019.
FAN W. Study on the dynamic mechanical properties of polysiloxane modified silica gel and polyurethane foam[D]. Xi'an: Xi'an University of Technology, 2019.
LIU Z, BESSELING N A M, MENDES E, et al. Self-healing supramolecular polymer nanocomposites[C]//Proceedings of the 3rd International Conference on Self-Healing Materials. Bath: ICHSHM, 2013: 684-687.
HUANG Y H , SHI Y , XUE L , et al. Progress in research and application of aviation silicone rubber material[J]. Journal of Aeronautical Materials, 2016, 36 (3): 79- 91.
MITROFANOV L A , SIDOROVICH Y A , KARLIN A V , et al. The question of molecular interaction in polyborondimethylsiloxanes (PBDMS)[J]. Polymer Science U.S.S.R, 1969, 11 (4): 882- 888.
LIU C Y , HE J S , RUYMBEKE E V , et al. Evaluation of different methods for the determination of the plateau modulus and the entanglement molecular weight[J]. Polymer, 2006, 47, 4461- 4479.