Synthesis and characterization of a novel functional biodegradable material, poly(lactic acid-co-borneol)

Figures & data

Scheme 1 The synthetic route of PLAB.

Table 1. The influences of different catalysts on the reaction. ^a

Run	Catalysts	Appearance of product	Yield (%)	[η] (dL g^−1)
1	SnCl2	Yellowish solid	43	0.51
2	SnO	White powder	33	0.71
3	ZnO	Yellowish powder	41	0.70
4	ZnCl2	Yellowish solid	51	0.46
5	TSA	Yellowish solid	50	0.61

Figure 1 Influences of catalyst SnO dosage on the viscosity of PLAB (conditions: 140 °C and 5 h).

Figure 2 Influences of melt polymerization temperature on the viscosity of PLAB (conditions: 5 h and catalyst SnO dosage 0.3 wt%).

Figure 3 Influences of melt polymerization time on viscosity of PLAB (conditions: 170 °C and catalyst SnO dosage 0.3 wt%).

Table 2. The influences of molar feed ratios on yield, [η], and M _n of the copolymers. ^a

Run	LA/borneol		Appearance of product	Yield (%)	[η] (dL g^−1)	M NMR ^b (Da)	M n (Da)	M w (Da)	M w/M n
	Feed	Test ^b
1	15/1	19/1	Yellowish solid	38	1.18	1600	2100	3300	1.57
2	32/1	36/1	White powder	46	1.05	2800	2300	3600	1.57
3	64/1	88/1	White powder	43	1.51	6500	6500	11,900	1.83
4	128/1	135/1	White powder	38	1.85	9900	5200	10,600	2.04

Figure 4 FTIR spectrum of PLAB synthesized as the molar feed ratio 64/1 (LA/borneol).

Figure 5 ¹H-NMR spectrum of PLAB synthesized as the molar feed ratio 64/1 (LA/borneol).

Figure 6 GPC curve of PLAB synthesized as the molar feed ratio 64/1 (LA/borneol).

Table 3. The influences of molar feed ratio on the thermal properties of PLAB. ^a

Run	LA/borneol	T g (°C)	T m (°C)	ΔH (J g^−1)	T i (°C)	T f (°C)	T p (°C)
1	15/1	24.7	ND ^b	ND ^b	224.3	321.4	276.5
2	32/1	36.0	ND ^b	ND ^b	196.5	283.2	253.4
3	64/1	49.2	ND ^b	ND ^b	196.5	302.3	263.2
4	128/1	49.1	ND ^b	ND ^b	196.5	298.2	254.5
PDLLA [15]		54.6	120.0	17.12	217.0	254.9	238.1

Figure 7 Differential thermogravimetry (DTG) curve of PLAB synthesized as the molar feed ratio 64/1 (LA/borneol).

Figure 8 XRD spectra of PLAB with different molar feed ratios (LA/borneol).

Table 4. The influences of molar feed ratio on the XRD results of PLAB ^a .

		2θ			Crystallite dimension (10^−10m)
Run	LA/borneol	Face (110)	Face (020)	Crystallinity (%)	L 110	L 020
1	15/1	Amorphous
2	32/1	16.7	19.0	16.4	295.9	144.2
3	64/1	16.6	19.0	11.4	268.6	159.0
4	128/1	16.7	19.1	16.0	216.2	159.7
PDLLA [16]		16.7	19.1	20.8	154.4	53.9

Zhao , YM , Wang , ZY and Yang , F . 2005 . Characterization of poly(D,L-lactic acid) synthesized by direct melt polymerization and its application in Chinese traditional medicine compound prescription microspheres . Journal of Applied Polymer Science , 97 : 195

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Wang , ZY , Zhao , YM and Yang , F . 2006 . Syntheses of poly(lactic acid-co-glycolic acid) serial biodegradable polymer materials via direct melt polycondensation and their characterization . Journal of Applied Polymer Science , 99 : 244

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