Toughing Polylactide with Topological Slide-ring Structure and Its Shape Memory Effect and Mechanism†

doi:10.7503/cjcu20180293

Abstract

Abstract:

To toughen brittle poly(L-lactic acid), the topological slide-ring architecture was introduced by ring opening polymerization of L-lactic acid initiated by hydroxypropyl modified α-CD-based polyrotaxane(HPPR). The thermal properties, mechanical properties, dynamic mechanical properties and shape memory performance of slide-ring polylactic acid based polyurethane(SR-PLAU) and other all samples were investigated. The results show that, the embedding of the slide-ring structure not noly greatly improves the strain at break of polylactic acid, and significantly improves the mechanical properties, but also enables the material good shape memory performance, compared to CC-PLAU and PLA/HPPR. The shape memory mechanism of SR-PLAU was proposed and demonstrated by the stress relaxation characteristics of the materials.

Key words: Topological slide-ring, Polylactide, Toughen, In-situ reactive compatibilization, Shape memory effect

CLC Number:

O631.1⁺1

TrendMD:

WU Ruiqing,LAI Jingjuan,PAN Yi,DENG Jinni,ZHENG Zhaohui,DING Xiaobin. Toughing Polylactide with Topological Slide-ring Structure and Its Shape Memory Effect and Mechanism^†[J]. Chem. J. Chinese Universities, 2018, 39(12): 2797.

Figures/Tables 12

Scheme 1 Synthesis route of the chemically cross-linked PLAU

Scheme 2 Synthesis route of HPPR

Scheme 3 Synthesis route of PLLA-based polyurethane with topological slide-ring structure(SR-PLAU)

Table 1 Components and properties of all prepolymers

Polymer	Molar fraction(%)			M_n	$T g a$ /℃	$T m a$ /℃	ΔH_m/(J·g^-1)	$X c b$ (%)
Polymer	n(LLA)/mol	HPPR	BDO	M_n	$T g a$ /℃	$T m a$ /℃	ΔH_m/(J·g^-1)	$X c b$ (%)
PLA-diol	1	0	0.25	44235	53.6	145.9	33.2	35.47
SG-PLA-0.25	1	0.25	0	857361	55.8	158.7	38.9	41.56
SG-PLA-0.5	1	0.5	0	528336	54.9	155.6	35.5	37.93
SG-PLA-1.0	1	1.0	0	353795	53.5	146.5	32.4	34.62
SG-PLA-2.0	1	2.0	0	273156	52.4	144.6	31.9	34.08

Table 1 Components and properties of all prepolymers

Polymer	Molar fraction(%)			M_n	$T g a$ /℃	$T m a$ /℃	ΔH_m/(J·g^-1)	$X c b$ (%)
Polymer	n(LLA)/mol	HPPR	BDO	M_n	$T g a$ /℃	$T m a$ /℃	ΔH_m/(J·g^-1)	$X c b$ (%)
PLA-diol	1	0	0.25	44235	53.6	145.9	33.2	35.47
SG-PLA-0.25	1	0.25	0	857361	55.8	158.7	38.9	41.56
SG-PLA-0.5	1	0.5	0	528336	54.9	155.6	35.5	37.93
SG-PLA-1.0	1	1.0	0	353795	53.5	146.5	32.4	34.62
SG-PLA-2.0	1	2.0	0	273156	52.4	144.6	31.9	34.08

Table 2 Gel content(G) of CC-PLAU, PLA/HPPR blends and SR-PLAUs

Sample	Molar fraction of HPPR(%)	G(%)	Sample	Molar fraction of HPPR(%)	G(%)
CC-PLAU	0	95.3±1.2	SR-PLAU-0.5	0.5	93.3±0.5
PLA/HPPR	2.0	83.2±0.7	SR-PLAU-1.0	1.0	93.3±1.3
SR-PLAU-0.25	0.25	92.6±1.3	SR-PLAU-2.0	2.0	95.4±1.1

Table 3 Thermal properties of CC-PLAU, PLA/HPPR blends and SR-PLAUs

Sample	$T g a$ /℃	$T m a$ /℃	Δ $H m a$ /(J·g^-1)	$X m b$ (%)
CC-PLAU	57.6(62.80^c)	157.4	17.2	18.38
PLA/HPPR-2.0	54.6(75.92^c)	148.6	11.3	12.07
SR-PLAU-0.25	57.7(77.91^c)	156.2	21.2	22.65
SR-PLAU-0.5	56.9(69.06^c)	155.8	19.8	21.15
SR-PLAU-1.0	55.3(66.66^c)	153.4	15.4	16.45
SR-PLAU-2.0	53.7(60.38^c)	152.7	13.9	14.85

Table 3 Thermal properties of CC-PLAU, PLA/HPPR blends and SR-PLAUs

Sample	$T g a$ /℃	$T m a$ /℃	Δ $H m a$ /(J·g^-1)	$X m b$ (%)
CC-PLAU	57.6(62.80^c)	157.4	17.2	18.38
PLA/HPPR-2.0	54.6(75.92^c)	148.6	11.3	12.07
SR-PLAU-0.25	57.7(77.91^c)	156.2	21.2	22.65
SR-PLAU-0.5	56.9(69.06^c)	155.8	19.8	21.15
SR-PLAU-1.0	55.3(66.66^c)	153.4	15.4	16.45
SR-PLAU-2.0	53.7(60.38^c)	152.7	13.9	14.85

Table 4 Mechanical properties of CC-PLAU, PLA/HPPR blends and SR-PLAUs*

Sample	Molar fraction of HPPR(%)	E/MPa	σ_m/MPa	ε_b(%)
CC-PLAU	0	2202±97.7	48±3.2	6.0±0.8
PLA/HPPR-2.0	2.0	1822±119.2	49.3±2.2	14.7±1.1
SR-PLAU-0.25	0.25	2023±168.6	46.6±0.8	10.5±1.2
SR-PLAU-0.5	0.5	1713±142.3	43.9±1.2	17.6±1.7
SR-PLAU-1.0	1.0	1428±87.2	41.6±1.4	35.6±5.7
SR-PLAU-2.0	2.0	1266±53.8	40.2±1.4	60.5±4.5

Fig.1 Thermal-mechanical properties of CC-PLAU, PLA/HPPR and SR-PLAUs

Table 5 Thermal-mechanical properties of CC-PLAU, PLA/HPPR and SR-PLAUs*

Sample	T_g/℃	E'_{(0 ℃)}/MPa	E'_{(80 ℃)}/MPa	E $' (T g - 30 ℃)$ /MPa	E $' (T g + 15 ℃)$ / MPa	E'_R
CC-PLAU	75.92	2349	608.2	1864	407.6	4.57
PLA/HPPR-2.0	65.17	2032	271.7	1654	271.17	6.09
SR-PLAU-0.25	77.91	2229	146.8	1430	123.86	11.55
SR-PLAU-0.5	69.06	1831	133.9	1536	95.7	16.05
SR-PLAU-1.0	66.66	1529	95.7	1232	85.8	14.36
SR-PLAU-2.0	60.38	1292	91.52	1210	63	19.21

Table 5 Thermal-mechanical properties of CC-PLAU, PLA/HPPR and SR-PLAUs*

Sample	T_g/℃	E'_{(0 ℃)}/MPa	E'_{(80 ℃)}/MPa	E $' (T g - 30 ℃)$ /MPa	E $' (T g + 15 ℃)$ / MPa	E'_R
CC-PLAU	75.92	2349	608.2	1864	407.6	4.57
PLA/HPPR-2.0	65.17	2032	271.7	1654	271.17	6.09
SR-PLAU-0.25	77.91	2229	146.8	1430	123.86	11.55
SR-PLAU-0.5	69.06	1831	133.9	1536	95.7	16.05
SR-PLAU-1.0	66.66	1529	95.7	1232	85.8	14.36
SR-PLAU-2.0	60.38	1292	91.52	1210	63	19.21

Table 6 Shape memory properties of CC-PLAU, PLA/HPPR and SR-PLAUs

Sample	ε_n(%)	ε_m(%)	ε_u(%)	ε_p(%)	R_f(%)	R_r(%)
CC-PLAU	0.410	13.14	12.98	4.90	98.74	64.25
PLA/HPPR-2.0	0.400	14.92	14.04	3.29	93.25	79.41
SR-PLAU-0.25	0.325	22.04	21.34	3.33	96.85	85.71
SR-PLAU-0.5	0.358	24.24	23.49	3.00	96.86	88.59
SR-PLAU-1.0	0.178	24.72	23.80	0.78	96.28	97.46
SR-PLAU-2.0	0.162	22.48	21.67	0.64	96.37	97.77

Fig.2 Series of photographs showing the shape memory effect of SR-PLA from temporary spiral shape to permanent straight shape

Table 7 Measured stress relaxation and recovery parameters of the samples*

Sample	Peak relaxation modulus/MPa	Relaxation modulus^a/MPa	Relative relaxation modulus^a(%)	Strain recovery(%)
SR-PLAU-2.0	80.6	75.49	93.71	131.61
PLA/HPPR-2.0	102.7	49.03	47.73	76.01
CC-PLAU	116.7	52.74	45.19	53.03

References 21

[1]	Vieira A.C., Marques A.T., Cuedes R.M., Tita V., Procedia Engineering,2011, 10, 1597—1602
[2]	Farah S., Anderson D.G., Langer R., Advanced Drug Delivery Reviews,2016, 107, 367—392
[3]	Rasal R.M., Hirt D.E., Journal of Biomedical Materials Research Part A,2009, 88A(4), 1079—1086
[4]	Liu B.J., Xinjiang Non-ferrous Metal, 2015, 21(5), 54—56
	(刘斌基. 新疆有色金属, 2015, 21(5), 54—56)
[5]	Tonchva A., Mincheva R., Kancheva M., European Polymer Journal,2016, 75, 223—233
[6]	Yang Y., Xiong Z., Zhang L.S., Materials and Design,2016, 91, 262—268
[7]	Ferri J.M., Fenollar O., Amparo J.V., Polymer International,2016, 65(4), 453—463
[8]	Wang L., Rhim J.W., Hong S., Food Science and Technology,2016, 68, 454—461
[9]	Yusoff R.B., Takagi H., Nakagaito A.N., Industrial Crops and Products,2016, 94, 564—573
[10]	Fukushima K., Tabuani D., Arena M., Reactive and Functional Polymers,2013, 73, 540—549
[11]	Ock H.G., Ahn K.H., Lee S.J., Kyu H., Macromolecules,2016, 49(7), 2832—2842
[12]	Chen B.K., Shen C.H., Chen A., Polymer Bulletin,2012, 69(3), 313—322
[13]	Ku Marsilla K.I., Verbeek C. J.R., European Polymer Journal,2015, 67, 213—223
[14]	Dean K.M., Petinakis E., Meure S., Journal of Polymers and the Environment,2012, 20(3), 741—747
[15]	Ito K., Current Opinion in Solid State & Materials Science, 2010, 14, 28—34
[16]	Zhao T., Haskell W.B., Macromolecules,2003, 36, 9859—9865
[17]	Wang H., Sun X., Seib P., J. Appl. Polym. Sci.,2001, 82, 1761—1767
[18]	Tavassoli K. M.H., Curtis J.M., van de Voort F. R., J. Am. Oil Chem. Soc.,2014, 91, 925—933
[19]	Goo N.S., Paik I.H., Yoon K.J., Jung Y.C., Cho J.W., Proc. SPIE,2004, 5390, 194—201
[20]	Kim B.K., Lee S.Y., Xu M., Polymer,1996, 37, 5781—5793
[21]	Ohtsuka K., Zhao C.,Polymer International, 2018, doi:10.1002/pi.5619