Silicon-containing poly(amide-imide)s: preparation, characterization, and properties

Figures & data

Figure 1. FT-IR spectrum of silicone-based diamine.

Figure 2. ¹H-NMR spectrum of silicone-based diamine.

Figure 3. DSC traces of polymers.

Figure 4. TGA curves of polymers.

Figure 5. WAXD pattern of PPDA-polymer.

Figure 6. SEM image of PPDA-polymer.

Scheme 1. Preparation of silicone-based diamine.

Scheme 2. Preparation of diimide-diacid.

Table 1. Characteristic data of diimide-diacid compound.

Structure	FT-IR (KBr, cm^−1)	^1H-NMR (DMSO-d6, δ)	Elemental analysis (%)
			Calc.	Found
Diimide-diacid	3425 (OH)	6.71 (d,2H)	C (67.56)	C (67.64)
	3041 (CH, Aromatic)	7.00 (d,2H)
	1775 (C=O, Imide I)	7.29 (dd,2H)
	1715 (C=O, Imide II)	7.34 (s,2H)	H (3.48)	H (3.53)
	1487 (Si–Ph)	7.40 (dd,4H)
	1385 (C–N, Imide III)	7.48 (d,4H)
	1294 (C–O)	7.58 (d,2H)
	1186 (Si–O)	8.01 (d,2H)	N (3.75)	N (3.68)
	717 (C=O, Imide IV)	8.32 (d,2H)
		8.34 (s,2H)
		13.71 (s,2H)

Scheme 3. Preparation of silicon-containing poly(amide-imide)s.

Table 2. Characteristic data of polymers.

Structure	Yield (%)	FT-IR (KBr,cm^−1)	Elemental analysis (%)		Inherent viscosity (dL/g)	Mw/Mn (g/mol)
			Calc.	Found
PPDA-polymer	97	3318 (NH)	C (70.42)	C (70.26)	0.55	83,000/46,000
		3048 (CH, Aromatic)
		1773 (C=O, Imide I)
		1722 (C=O, Imide II)
		1654 (C=O, Amide I)	H (3.67)	H (3.56)
		1605 (C=O, Amide II)
		1483 (Si–Ph)
		1382 (C–N, Imide III)
		1288 (C–O)	N (6.84)	N (6.98)
		1181 (Si–O)
		719 (C=O, Imide IV)
NDA-polymer	94	3310 (NH)	C (71.89)	C (71.77)	0.53	74,500/43,500
		3052 (CH, Aromatic)
		1775 (C=O, Imide I)
		1723 (C=O, Imide II)	H (3.69)	H (3.78)
		1657 (C=O, Amide I)
		1600 (C=O, Amide II)
		1482 (Si–Ph)
		1380 (C–N, Imide III)	N (6.45)	N (6.36)
		1283 (C–O)
		1183 (Si–O)
		721 (C=O, Imide IV)
DAP-polymer	96	3342 (NH)	C (68.86)	C (68.72)	0.54	76,000/45,500
		3054 (CH, Aromatic)
		1774 (C=O, Imide I)
		1720 (C=O, Imide II)
		1658 (C=O, Amide I)	H (3.54)	H (3.62)
		1592 (C=O, Amide II)
		1486 (Si–Ph)
		1378 (C–N, Imide III)
		1284 (C–O)	N (8.55)	N (8.42)
		1184 (Si–O)
		718 (C=O, Imide IV)
ODPDA-polymer	98	3315 (NH)	C (71.21)	C (71.12)	0.58	78,000/44,500
		3050 (CH, Aromatic)
		1776 (C=O, Imide I)
		1723 (C=O, Imide II)
		1657 (C=O, Amide I)	H (3.74)	H (3.63)
		1604 (C=O, Amide II)
		1480 (Si–Ph)
		1383 (C–N, Imide III)
		1288 (C–O)	N (6.15)	N (6.28)
		1185 (Si–O)
		725 (C=O, Imide IV)

Table 3. Solubility behavior of polymers.

Polymer	NMP	DMAc	DMF	DMSO	m-Cresol	Pyridine	THF
PPDA-polymer	++	++	+	+	+	±	−
NDA-polymer	++	++	+	+	+	±	−
DAP-polymer	++	++	+	+	+	±	−
ODPDA-polymer	++	++	+	+	++	+	++

Notes:

(++)soluble by stirring; (+)soluble by heating and stirring; (±)partially soluble by heating and stirring; (−)insoluble.

Table 4. Thermal properties and flame retardant data of polymers.

Polymer	Tg (°C)	TIDT (°C)	T10 (°C)	Char yield at 700 °C (%)	LOI (v%)
PPDA-polymer	196	287	400	44	35.1
NDA-polymer	192	283	392	43	34.7
DAP-polymer	190	280	386	41	33.9
ODPDA-polymer	187	275	375	39	33.1