Polybenzoxazine/Polyhedral Oligomeric Silsesquioxane (POSS) Nanocomposites

Abstract

The organic/inorganic hybrid materials from polyhedral oligomeric silsesquioxane (POSS, inorganic nanoparticles) and polybenzoxazine (PBZ) have received much interesting recently due to their excellent thermal and mechanical properties, flame retardance, low dielectric constant, well-defined inorganic framework at nanosized scale level, and higher performance relative to those of non-hybrid PBZs. This review describes the synthesis, dielectric constants, and thermal, rheological, and mechanical properties of covalently bonded mono- and multifunctionalized benzoxazine POSS hybrids, other functionalized benzoxazine POSS derivatives, and non-covalently (hydrogen) bonded benzoxazine POSS composites.

Keywords: POSS; hydrogen bonding; nanocomposites; polybenzoxazine.

Figure 1

Preparation and thermally induced ring-opening polymerization of (A) P-a and (B) B-a types of BZ monomers.

Figure 2

Chemical structures of silsesquioxanes: (a) random structure, (b) ladder structure, (c) T₈, (d) T₁₀, (e) T₁₂ cage structure, and (f) partial cage structure [59]. Reproduced with permission from Elsevier.

Figure 3

(a) The mechanism and the corresponding chemical structure for the synthesis of the VP-a monomer, as well as the preparation of the BZ-POSS-1 macromonomer through hydrosilylation; (b) synthesis of the BZ-POSS-2 macromonomer from amino-POSS [105]. Reproduced with permission from Elsevier.

Figure 4

Preparation of PBZ/POSS nanocomposites from BZ-POSS monomers containing (a) P-a and (b) B-a type BZ monomers [105]. Reproduced with permission from Elsevier.

Figure 4

Preparation of PBZ/POSS nanocomposites from BZ-POSS monomers containing (a) P-a and (b) B-a type BZ monomers [105]. Reproduced with permission from Elsevier.

Figure 5

Preparation of multi-functionalized (OBZ POSS) (a) through hydrosilylation from Q₈M₈^H (b) with VB-a monomer and subsequent formation of PBZ/POSS nanocomposites with a network structure [107]. Reproduced with permission from Elsevier.

Figure 6

The hydrosilylation of vinyl benzyl chloride monomer with Q₈M₈^H (a) to form OVBC-POSS (b) and OVBN₃-POSS (c) and the click reaction to give OBZ-POSS (d) and thermal curing to give PBZ/POSS nanocomposite (e) [108]. Reproduced with permission from Elsevier.

Figure 7

Advancing contact angles for water, diiodomethane (DIM), and ethylene glycol (EG) of (a) a P4VP thin film and (b) surface modified with the OBZ-POSS thin film [108]. Reproduced with permission from Elsevier.

Figure 8

Synthesis of OPS-BZ and possible morphology of POSS/PBZ nanocomposites after thermal curing [109]. Reproduced with permission from American Chemical Society.

Figure 9

HR-TEM images for POSS/PBZ =30/70 nanocomposites (scale bars for A: 50 nm; B: 20 nm; C: 10 nm, and D: 5 nm) [109]. Reproduced with permission from American Chemical Society.

Figure 10

(a–d) The reaction and chemical structures for the preparation from Q₈M₈^H (a) to form OA-POSS (b), OP-POSS (c), and VBa-POSS (d); the possible morphology of VBa/VBa-POSS blends after the thermal curing (e) [110]. Reproduced with permission from John Wiley and Sons.

Figure 11

Storage moduli of VBa/VBa-POSS nanocomposites after thermal curing [110]. Reproduced with permission from John Wiley and Sons.

Figure 12

SEM image (a), Si-mapping image (b), EDX analysis (c), and TEM image of VBa/VBa-POSS = 70/30 after thermal curing (d) [110]. Reproduced with permission from John Wiley and Sons.

Figure 13

Synthesis of POSS-BZ monomers of POSS-EBzo (a), POSS-GBzo (b), and POSS-VBzo (c) [111]. Reproduced with permission from Royal Society of Chemistry.

Figure 14

(a) Q₈M₈^H; (b) synthesis of POSS-Bz; (c) the schematic representation of BPZ/POSS nanocomposite with the cross-linked lamellae structure [112]. Reproduced with permission from Royal Society of Chemistry.

Figure 15

Preparation of OG-POSS and the subsequent reaction with VBa monomer to give PBZ/POSS nanocomposites [113]. Reproduced with permission from John Wiley and Sons.

Figure 16

Preparation of POSS-PU-PBZ nanocomposites [116]. Reproduced with permission from Royal Society of Chemistry

Figure 17

Syntheses of (A) PA-OH, PA-ac, and PA-T and (B) OBA-POSS [117]. Reproduced with permission from American Chemical Society.

Figure 18

The TEM images and their corresponding SAED patterns of PA-T/OBA-POSS nanocomposites with different OBA-POSS contents of (a) 100/0, (b) 95/5, (c) 90/10, (d) 80/20, (e) 70/30, (f) 60/40, (g) 50/50, and (h) 0/100 [117]. Reproduced with permission from American Chemical Society.

Figure 19

Possible three-step mechanism for self-assembly structure of PA-T/OBA-POSS hybrid complexes: (a) PA-T was miscible with OBA-POSS; (b) the OBA-POSS separated from the thermal cured PA-T through the reaction-induced microphase separation mechanism; (c) the self-aggregation of OBA-POSS was restricted by complementary A–T multiple hydrogen-bonding interaction and the self-assembly lamellae structure of the POSS units via the subsequent growth along (012) plane [117]. Reproduced with permission from American Chemical Society.

Figure 20

The cartoon representation of the Py-Bz-T/OBA-POSS/SWCNT ternary hybrid complexes formation [118]. Reproduced with permission from Royal Society of Chemistry.

Figure 21

TEM images of pure SWCNT (a,b), the Py-Bz-T/OBA-POSS/SWCNT (1 wt%) (c,d), and the Py-Bz-T/OBA-POSS/SWCNT (3 wt %) hybrid complex (e,f) [118]. Reproduced with permission from Royal Society of Chemistry.