GuangMing Zhu

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Name: 朱光明; GuangMing Zhu

Organization: Northwestern Polytechnical University

Department:

Title: Professor

TOPICS

Organic Chemistry

Liquid Crystal

Chemicals
References

A novel shape memory poly(ε-caprolactone) network via UV-triggered thiol-ene reaction

Co-reporter:

Journal of Polymer Science Part B: Polymer Physics 2017 Volume 55(Issue 8) pp:692-701

Publication Date(Web):2017/04/01

DOI:10.1002/polb.24314

ABSTRACTA facile method to prepare shape memory polymers crosslinked by SiO2 is described. A series of biodegradable shape memory networks were obtained through thiol-ene reaction triggered by UV irradiation between surface-thiol-modified SiO2 nanoparticles and end-acrylate poly (ε-caprolactone) (PCL). The highly selective thiol-ene reaction ensured a uniform distribution of PCL chains between crosslinkers, contributing well-defined network architecture with enhanced mechanical and shape-memory properties. Thiol-functionalized silica nanoparticle was characterized by using FTIR and XPS analysis, and 1H NMR spectra was used to confirm the successful modification of terminal hydroxyl group of PCL diol. Surface-modified silica particles were found well dispersible in acrylate-capped PCL supported by SEM. Thermal and crystalline behaviors of the obtained polymers were analyzed by DSC and XRD, and DMA measurement proved good mechanical property. The shape memory behavior and tensile strength was somewhat tunable by the length of PCL. Acceptably, sample SiO2-SMP2k presented 99% recovery ratio and 97% shape fixity, and its relatively high tensile strength showed an attractive potential for biomedical application. Finally, a possible molecular mechanism accounting for the shape memory property was illustrated. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2017, 55, 692–701

Electroactive shape memory cyanate/polybutadiene epoxy composites filled with carbon black

Co-reporter:Kun Wang;Guang-ming Zhu 朱光明;Xiao-gang Yan;Fang Ren

Chinese Journal of Polymer Science 2016 Volume 34( Issue 4) pp:466-474

Publication Date(Web):2016 April

DOI:10.1007/s10118-016-1766-8

Electroactive shape memory composites were synthesized using polybutadiene epoxy (PBEP) and bisphenol A type cyanate ester (BACE) filled with different contents of carbon black (CB). Dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), electrical performance and electroactive shape memory behavior were systematically investigated. It is found that the volume resistivity decreased due to excellent electrical conductivity of CB, in turn resulting in good electroactive shape memory properties. The content of CB and applied voltage had significant influence on electroactive shape memory effect of developed BACE/PBEP/CB composites. Shape recovery can be observed within a few seconds with the CB content of 5 wt% and voltage of 60 V. Shape recovery time decreased with increasing content of CB and voltage. The infrared thermometer revealed that the temperature rises above the glass transition temperature faster with the increase of voltage and the decrease of resistance.

Cyanate ester resin filled with graphene nanosheets and CoFe2O4-reduced graphene oxide nanohybrids as a microwave absorber

Co-reporter:Fang Ren, Guangming Zhu, Penggang Ren, Kun Wang, Xiaoping Cui, Xiaogang Yan

Applied Surface Science 2015 Volume 351() pp:40-47

Publication Date(Web):1 October 2015

DOI:10.1016/j.apsusc.2015.05.101

Highlights

•: RGO-CoFe₂O₄ nanohybrid was synthesized by a facile hydrothermal route in combination with calcination at 550 °C.
•: GNSs/RGO–CoFe₂O₄ nanohybrid/CE composites exhibited excellent electromagnetic absorption properties and wide absorption bandwidth.
•: Too high permittivity of the composites is harmful to the impedance match and results in strong reflection and weak absorption.

Thermal and shape memory properties of cyanate/polybutadiene epoxy/polysebacic polyanhydride copolymer

Co-reporter:Kun Wang;Yongkun Wang;Fang Ren

Journal of Applied Polymer Science 2015 Volume 132( Issue 23) pp:

Publication Date(Web):

DOI:10.1002/app.42045

ABSTRACT

A novel thermal-induced shape memory polymer was synthesized by copolymerization of a new kind of epoxy resin-polybutadiene epoxy (PBEP), bisphenol A-type cyanate ester (BACE), and polysebacic polyanhydride (PSPA) with different mass ratios. Fourier transform infrared spectroscopy (FTIR), bending test, dynamic mechanical analysis (DMA), and shape memory property were investigated systematically. It was found that the PSPA significantly enhanced the bending strength and flexural modulus. The DMA results showed that the glass transition temperature reduced with increasing content of PSPA. Furthermore, the shape memory tests proved that the copolymer possessed excellent shape memory properties. The shape recovery time decreased with increasing content of PSPA and temperature. The shape memory rate increased as the PSPA content increased. The shape recovery ratio decreased with increasing cycle times. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42045.

Cyanate ester filled with graphene nanosheets and multi-walled carbon nanotubes as a microwave absorber

Co-reporter:Fang Ren;Jianqiang Xie;Kun Wang

Journal of Polymer Research 2015 Volume 22( Issue 5) pp:

Publication Date(Web):2015 May

DOI:10.1007/s10965-015-0738-y

Microwave absorbing composites with cyanate ester (CE) as matrix and both graphene nanosheets (GNSs) and multi-walled carbon nanotubes (MWCNTs) as absorbers were prepared, and their microwave absorbing properties were investigated in the frequency range of 2–18 GHz. The microstructures of the composites show a uniform dispersion of the GNSs and MWCNTs in the matrix. The complex permittivity of the composites increase with increasing fillers content. As microwave absorbing materials, the GNSs/MWCNTs/CE composites possess excellent absorption properties. Reflection loss values exceeding-5 dB (more than 70 % absorption) can be obtained in the frequency range of 9.12–14.15GHz with the count of 1.5 wt.% GNSs and 0.5 wt.% MWCNTs. Especially, a minimum reflection loss value of -32.4 dB was obtained at 11.2 GHz for the composite thickness of 2 mm. The enhanced microwave absorbing properties were also explained based on the structures of the composites. The mechanical properties of the composites were investigated in detail. It is observed that GNSs/MWCNTs reinforced CE composites demonstrated improved mechanical properties than that of CE matrix, which make them suitable for use in aerospace applications and radar absorbing material (RAM).

In situ polymerization of graphene oxide and cyanate ester–epoxy with enhanced mechanical and thermal properties

Co-reporter:Fang Ren, Guangming Zhu, Penggang Ren, Yongkun Wang, Xiaoping Cui

Applied Surface Science 2014 Volume 316() pp:549-557

Publication Date(Web):15 October 2014

DOI:10.1016/j.apsusc.2014.07.159

Highlights

•: Uniformly dispersed GO/cyanate ester (CE)–epoxy (EP) composites were successfully synthesized by in situ polymerization.
•: The reaction mechanisms were discussed and were testified by FT-IR and XPS.
•: GO reinforced EP-CE composites demonstrated improved mechanical properties and better thermal stability than that of EP-CE matrices.

Short glass fiber reinforced radiation crosslinked shape memory SBS/LLDPE blends

Co-reporter:Wang Yongkun;Zhu Guangming;Tang Yusheng;Liu Tingting;Xie Jianqiang ;Ren Fang

Journal of Applied Polymer Science 2014 Volume 131( Issue 17) pp:

Publication Date(Web):

DOI:10.1002/app.40691

ABSTRACT

The poly(styrene-b-butadiene-b-styrene) triblock copolymer (SBS) and linear low density polyethylene(LLDPE) were blended and irradiated by γ-rays to prepare shape memory polymer(SMP). Various amounts of short glass fiber (SGF) were filled into SMP to form a novel shape memory SGF/SBS/LLDPE composite. The effect of SGF on the shape memory SGF/SBS/LLDPE composite was studied in terms of mechanical, dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC) and shape memory effects. It is found that the SGF act as reinforcing fillers and significantly augment the glassy and rubbery stated moduli, tensile strength and shape memory properties. When SGF content is <2.0 wt %, full recovery can be observed after only several minutes at different temperatures and shape recovery speed reduces as the SGF content increases. The shape recovery time decreases as the temperature of the shape memory test increases and the shape recovery rate decreases with increment of cycle times. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40691.

Preparation and characterization of SiO2-coated 2,4-hexadiyn-1,6-bis(ethylurea) microcapsules

Co-reporter:Huan Cheng

Chemical Research in Chinese Universities 2014 Volume 30( Issue 3) pp:431-436

Publication Date(Web):2014 June

DOI:10.1007/s40242-014-3344-3

A novel kind of time-temperature indicator, SiO2-coated 2,4-hexadiyn-1,6-bis(ethylurea) microcapsules, has been fabricated by coating SiO2 on 2,4-hexadiyn-1,6-bis(ethylurea). This kind of microcapsules is a model hydrophilic indicator, its stability is improved. And temperature-induced color change is irreversible even under varying irradiation. The influences of ammonia, tetraethyl orthosilicate(TEOS) and temperature on the product have been investigated. 2,4-Hexadiyn-1,6-bis(ethylurea) and the coated particles have been characterized by means of elemental analysis, mass spectrum, FTIR and Raman spectra and DSC, SEM, TEM and DLS analyses. The results indicate that 2,4-hexadiyn-1,6-bis(ethylurea)/SiO2 ratios, ammonia concentration and temperature could modulate the monodispersity and size of the microcapsules. The experiments indicate that when the molar ratio of 2,4-hexadiyn-1,6-bis(ethylurea)/SiO2/ammonia is 1:3:3.5 and temperature is 40 °C, the obtained microcapsules are well coated with the best monodispersity. Such sustained-release and hydrophilic microcapsules have very good prospects as a novel time-temperature chromatic indicator.

Microwave absorbing properties of graphene nanosheets/ epoxy-cyanate ester resins composites

Co-reporter:Fang Ren;Yongkun Wang;Xiaoping Cui

Journal of Polymer Research 2014 Volume 21( Issue 11) pp:

Publication Date(Web):2014 November

DOI:10.1007/s10965-014-0585-2

Microwave absorbing composites with epoxy-cyanate ester (EP-CE) as matrix and graphene nanosheets (GNSs) as absorbers were prepared, and their electromagnetic and microwave absorbing properties were investigated in the frequency range of 2.6–12.4 GHz. The microstructures of the composites showed a uniform dispersion of the GNSs in the matrix. The complex permittivity of the composites increased with increasing filler content. As absorbing materials, the GNSs/EP-CE composites possess excellent absorption properties. And the composites with 3 wt.% of GNSs exhibited high values of reflection loss (>10 dB) over a wide frequency range 5.8–6.6 GHz and maximum loss is 15.7 dB at 5.8 GHz at a thickness of 3 mm. The minimum reflection loss was found to move toward to the low frequency region (from 10.2 to 4.5 GHz) with increasing composites thickness. Especially, a minimum reflection loss value of −21.4 dB was obtained at 4.5 GHz for the composite thickness of 4 mm. Moreover, the thermal properties of the composites were also investigated in detail. It is observed that GNSs reinforced EP-CE composites demonstrated better thermal stability than that of EP-CE matrix, which make them suitable for use in aerospace applications and radar absorbing material (RAM).

Mechanical and shape memory behavior of chemically cross-linked SBS/LDPE blends

Co-reporter:Yongkun Wang;Yusheng Tang;Jianqiang Xie

Journal of Polymer Research 2014 Volume 21( Issue 4) pp:

Publication Date(Web):2014 April

DOI:10.1007/s10965-014-0405-8

A series of polymeric shape memory system of chemically cross-linked poly(styrene-b-butadiene-b-styrene) triblock copolymer(SBS) and linear low density polyethylene(LDPE) blends were developed and characterized. The chemically cross-linked SBS/LDPE blends were prepared by varying the amount of initiator (DCP) between 0 and 1.5 wt.% and the ratio of SBS/LDPE ranges from 90/10 to 60/40. The cross-linked SBS/LDPE blends were fully characterized by gel content, tensile test, dynamic mechanical analysis (DMA), differential scanning calorimeter (DSC) and shape memory behavior. Results demonstrate that the cross-linking degree increases with the increment of the DCP content, leading to reductions in tensile strength and elongation at break. The transition temperature of cross-linked SBS/LDPE blends is tunable through changing SBS/LDPE ratio and DCP content. DMA test shows that the melt strength of the blends is influenced by the DCP and LDPE content. The chemically cross-linked SBS/LDPE blends have excellent shape memory effect when the cross-linking degree between 46 and 77 %. The shape recovery time decreases as the test temperature increases and the shape recovery rate decreases with cycle times increasing.

Electroactive shape-memory effects of hydro-epoxycarbon black composites

Co-reporter:Kun Wei;Guangming Zhu;Yusheng Tang;Ximin Li

Polymer Journal 2013 45(6) pp:671-675

Publication Date(Web):2012-10-24

DOI:10.1038/pj.2012.185

Electroactive shape-memory hydro-epoxy/carbon black composites are investigated in this study. The thermomechanical and the shape-memory properties of these composites are characterized using dynamic mechanical analysis and U-type shape-memory tests. These results indicate that the glass transition temperature (Tg) of the composites decreases first and then increases slightly as the carbon black content increases. The storage modulus at high temperatures increases as the carbon black content increases. The percolation threshold of the electroactive shape-memory hydro-epoxy composite is lower than that for many other composites. Because of the low percolation threshold, the electroactive shape-memory hydro-epoxy composite exhibits excellent shape-memory property. The sample filled with 1.9 wt% carbon black can recover nearly 100% of its original shape in only a few minutes under an applied voltage of 200 V.

An investigation on shape memory behaviours of hydro-epoxy/glass fibre composites

Co-reporter:Kun Wei, Guangming Zhu, Yusheng Tang, Ximin Li, Tingting Liu, Lei Niu

Composites Part B: Engineering 2013 Volume 51() pp:169-174

Publication Date(Web):August 2013

DOI:10.1016/j.compositesb.2013.03.036

Shape-memory polymers (SMPs) have the capacity to return large strains by external stimuli. Among various SMPs, shape-memory epoxy has received considerable attention because of its superior mechanical and thermal properties as well as excellent shape-memory performance. In this study, short glass fibre-reinforced shape-memory hydro-epoxy composites are developed to improve further the mechanical property of shape-memory epoxy resin. The thermomechanical and shape-memory properties of the developed composite materials are investigated by dynamic mechanical analysis, bend test and shape recovery test. The results indicate that the glass modulus and bend strength of the developed composite materials initially increase and then slightly decrease with increasing short glass fibre content. The glass transition temperature of the developed composite materials does not change with increasing short glass fibre. When the short glass fibre content is less than 4.5 wt.%, full recovery can be observed after only several minutes at different temperatures. The shape-memory property of the composite materials is not affected greatly. However, when the short glass fibre content is more than 4.5 wt.%, the material would be destroyed after deformation.