Co-reporter:Jian Jiao;Lizhen Zhao;Lei Wang;Panpan Lv;Yonghong Cui;Guangli Wu
Polymer Composites 2016 Volume 37( Issue 7) pp:2142-2151
Publication Date(Web):
DOI:10.1002/pc.23393
A novel hybrid functional nanoparticle (denoted POSS-MPS) was synthesized by aminopropyl-functionalized mesoporous silica (AP-MPS) with glycidyl polyhedral oligomeric silsesquioxane (G-POSS). The G-POSS was employed as molecular caps to envelop the MPS and improve the interaction with the polymer matrix. The POSS-MPS hybrids were designed to improve the properties of cyanate ester (CE) without affecting its inherent properties. The POSS-MPS/CE composites exhibited excellent improvement in dielectric properties, mechanical properties, and thermal properties due to increase of voids volume in the composites and reinforcement of interface interaction between organic and inorganic phase. The dielectric constant (κ) and loss factor (tan δ) of composites with 4 phr of POSS-MPS reduced to 2.78 and 0.008 in comparison to pure CE with the value of 3.27 and 0.012, respectively. Moreover, the composites exhibited 14.3, 4.9, 57.5, and 8.7% enhancement in flexural strength, flexural modulus, impact strength, and glass transition temperature (Tg) in comparison to pure CE, respectively. The results manifested that introduction of POSS-MPS into CE exhibited toughening and reinforcing effects on the composites. POLYM. COMPOS., 37:2142–2151, 2016. © 2015 Society of Plastics Engineers
Co-reporter:Jian Jiao;Panpan Lv;Lei Wang;Yu Cai ;Peng Liu
Polymer Engineering & Science 2015 Volume 55( Issue 3) pp:565-572
Publication Date(Web):
DOI:10.1002/pen.23921
Octa-vinyl polyhedral oligomeric silsesquioxane (V-POSS) and octa-(methacryloxy) propyl polyhedral oligomeric silsesquioxane (M-POSS) were incorporated into PMMA to prepare POSS/PMMA hybrid materials at molecular level via in situ polymerization. The resulting hybrid materials showed only swelling instead of solution in ethyl acetate, while pristine PMMA completely dissolved in ethyl acetate; moreover, the M-POSS/PMMA hybrid materials exhibited more excellent resistance to solvent stress cracking. An excellent transparency was observed for all hybrid materials. Incorporation of V-POSS and M-POSS significantly improved thermal properties of PMMA. The thermal decomposition temperature of hybrid materials was enhanced except a slightly compromised initial decomposition temperature. The hybrid materials prepared with 0.2–0.6 mol% M-POSS or V-POSS improved the reinforcing and toughening properties in comparison to pristine PMMA. Also, the incorporation of POSS decreased the dielectric constant and dielectric loss of the hybrid materials with more voids introduced into the composites no matter the structure of POSS. POLYM. ENG. SCI., 55:565–572, 2015. © 2014 Society of Plastics Engineers
Co-reporter:Jian Jiao, Lei Wang, Panpan Lv, Yonghong Cui, Jie Miao
Materials Letters 2014 Volume 129() pp:16-19
Publication Date(Web):15 August 2014
DOI:10.1016/j.matlet.2014.05.010
•POSS–MPS are synthesized by grafting MPS with a layer of G-POSS.•POSS–MPS/EP nanocomposites exhibit a lower κ because of voids arising from POSS–MPS.•POSS–MPS/EP nanocomposites exhibit improved mechanical and thermal properties.•The properties of composites are affected with the content of POSS–MPS.The novel organic–inorganic particles (denoted POSS–MPS) were synthesized by the reaction of amino-functionalized mesoporous silica (NH2-MPS) with a wormhole framework structure and glycidyl polyhedral oligomeric silsesquioxane (G-POSS), and were employed as reinforcing agents to prepare POSS–MPS/epoxy resin (EP) nanocomposites. The retaining mesoporous structure of POSS–MPS was verified by TEM and N2 adsorption–desorption. The excellent improvement in dielectric properties, thermal properties and mechanical properties of the POSS–MPS/EP nanocomposites is ascribed to increase of voids volume and reinforcement of interfacial interaction between organic and inorganic phase in the composites. The POSS–MPS/EP nanocomposites containing 5 wt% of POSS–MPS showed a lower dielectric constant (κ=3.66) and loss factor (tan δ=0.017) in comparison to pristine EP with the value of 4.03 and 0.031, respectively. Moreover, the composites exhibited 23.8%, 43.5%, 159.8% and 59.8% enhancement in tensile strength, tensile modulus, elongation at break and glass transmission temperature (Tg) in comparison to pristine EP, respectively. The results manifested that introduction of POSS–MPS improved the mechanical properties, heat resistance and dielectric properties of EP.
Co-reporter:Jian Jiao, lei Wang, Panpan Lv, Peng Liu, Yu Cai
Materials Letters 2013 Volume 109() pp:158-162
Publication Date(Web):15 October 2013
DOI:10.1016/j.matlet.2013.07.070
•Nanoporous silicas with three frameworks are synthesized.•NPS/PMMA nanocomposites exhibit lower κ because of voids arising from NPS.•NPS/PMMA nanocomposites exhibit improved mechanical and thermal properties.•The properties of composites are affected with the content of BTESE.Periodic mesoporous organosilicas (PMOs) with 3D cubic framework and worm-hole framework, inorganic mesoporous silica with 3D cubic framework and organic–inorganic nanometer sized hollow spheres were synthesized with different molar ratios of 1,2-bis(triethoxysilyl)ethane (BTESE) and tetraethylorthosilicate (TEOS) as silica precursors, and were used to prepare nanoporous silica/poly(methyl methacrylate) (PMMA) nanocomposites with lower dielectric constant, higher thermal and mechanical properties. The micro-structures of above nanoporous silicas (NPSs) were retained in NPS/PMMA nanocomposites with 2 wt% loading of NPS. NPSs provided composites with lower dielectric constant (κ≈2.73) in comparison to pure PMMA (κ=2.91) due to introduction of voids. All the composites exhibited improved mechanical properties, glass transmission temperature (Tg) and thermal stability in comparison to PMMA. The tensile strength, tensile modulus, flexural strength and flexural modulus of the composites increased with the molar percentage of BTESE increased from 0% to 100%, and only slight compromised elongation at break and impact strength were observed.
Co-reporter:Panbo Liu;Ying Huang
Journal of Porous Materials 2013 Volume 20( Issue 1) pp:107-113
Publication Date(Web):2013 February
DOI:10.1007/s10934-012-9579-9
Ordered mesoporous carbon is synthesized by the organic–organic self-assembly method with novolac as carbon precursor and two kinds of triblock copolymers (Pluronic F127 and P123) as template. The hexagonal structure and a worm-hole structure are observed by TEM. The carbonization temperature is determined by TG and FT-IR. Characterization of physical properties of mesoporous carbon is executed by N2 absorption–desorption isotherms and XRD. The mass ratios of carbon precursor/template affect the textural properties of mesoporous carbon. The mesoporous carbon with F127/PF of 1/1 has lager surface area (670 m2 g−1), pore size (3.2 nm), pore volume (0.40 cm3 g−1), smaller microporous surface area (368 m2 g−1) and wall thickness (3.7 nm) compare to that with F127/PF of 0.5/1 (576 m2 g−1, 2.7 nm, 0.29 cm3 g−1, 409 m2 g−1 and 4.3 nm, respectively). The mesoporous carbon prepared by carbonization at high temperature (700 °C) exhibits lager surface area, lower pore size and pore volume than the corresponding one obtained at 500 °C. The structure and order of the resulting materials are notably affected with types of templates. The mesoporous carbon with P123 as template exhibits worm-hole structure compare to that with F127 as template with hexagonal structure. In general, the pore size of mesoporous carbon with novolac as precursor is smaller than that with resorcinol–formaldehyde as precursor.
