Jungang Gao

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Name: 高俊刚; JunGang Gao

Organization: Hebei University

Department: College of Chemistry and Environmental Science

Title:

TOPICS

Material Chemistry

Carbon Nanotubes

Polymer

POSS Radical Polymerization

Chemicals
References

Mechanical and thermal properties of cationic ring-opening o-cresol formaldehyde epoxy/polyurethane acrylate composites enhanced by reducing graphene oxide

Co-reporter:Hongzhe Han;Chunyan Jiang;Li Huo

Polymer Bulletin 2016 Volume 73( Issue 8) pp:2227-2244

Publication Date(Web):2016 August

DOI:10.1007/s00289-016-1605-7

Polyurethane acrylate (PUA) and o-cresol formaldehyde epoxy resin (o-CFER) is synthesized. The PUA/o-CFER glass fiber-reinforced composites cured by free radical/cationic ring-opening reaction are modified by the reducing graphene oxide (r-GO). Effect of r-GO on the thermal and mechanical properties of PUA/o-CFER glass fiber-reinforced composites are characterized by FTIR, DMA and TGA. The result of FTIR shows that the system has cured completely. DMA analysis indicates that this system has better compatibility, and the glass transition temperature (Tg) decreases with increasing r-GO content. TGA analysis shows that the initial thermal degradation temperature (Tid) and activation energy (Ea) enhance 13.1 °C and 3.12 kJ/mol, respectively. The tensile and impact strength of glass fiber-reinforced composites are approximately 50 and 60 % higher than those without r-GO. It is shown that the r-GO can enhance the mechanical properties and thermal stability of composites.

Preparation, curing, and properties of boron-containing bisphenol-S formaldehyde resin/o-cresol formaldehyde epoxy resin/nano-SiO2 composites

Co-reporter:Weihong Wu;Jingjing Leng;Zheng Wang;Hongqiang Qu

Macromolecular Research 2016 Volume 24( Issue 3) pp:209-217

Publication Date(Web):2016 March

DOI:10.1007/s13233-016-4031-7

Boron-containing bisphenol-S formaldehyde resin (BBPSFR) with different amounts of nano-SiO2 by in situ formation was used to cure o-cresol formaldehyde epoxy resin (o-CFER). The curing kinetics, dynamic mechanical properties, and thermal stability of BBPSFR/o-CFER/nano-SiO2 composites (BCS) were investigated by differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermogravimetry (TG), and thermogravimetrymass spectrometry (TGMS). Morphology of nano-SiO2-containing BBPSFR and glass fiber laminates of the BCS were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The mechanical properties and electrical properties were also determined. The results showed that nano-SiO2 accelerated the curing process and decreased the curing temperature; the non-isothermal curing kinetics of the BCS can be described by the two-parameter (m, n) Šesták-Berggren kinetic model, and the average value of m was 0.32 and n was 1.00. The thermal stability was enhanced by the addition of nano-SiO2, especially at higher temperatures, and the residual weight increased with increasing nano-SiO2 content. Incorporation of 6 wt% of nano-SiO2 increased the impact strength from 105 to 149 kJ/m2 and storage modulus at ambient from 6.85 to 12.7 GPa, and the TEM photograph of which showed that nano-SiO2 particles (about 50 nm) were dispersed in the matrix more uniformly. The volume resistance, Rv, and dielectric constant, ε, slightly increased when the nano-SiO2 content was 3 wt%.

Effect of carbon nanotube on the mechanical, plasticizing behavior and thermal stability of PVC/poly(acrylonitrile–styrene–acrylate) nanocomposites

Co-reporter:Chao Wang;Na Li;Li Huo

Polymer Bulletin 2015 Volume 72( Issue 8) pp:1849-1861

Publication Date(Web):2015 August

DOI:10.1007/s00289-015-1376-6

Polyvinylchloride (PVC)/poly(acrylonitrile–styrene–acrylate) (ASA)/multi-walled carbon nanotubes (MWCNTs) nanocomposites were prepared. The plasticizing behavior, dynamic mechanical properties, mechanical properties and thermal stability of the nanocomposites were studied. The results demonstrate that the plasticizing time shortens as the MWCNTs content increases. The nanocomposites show the best impact strength, which is 83.7 % higher than pure PVC/ASA blend and is 2.1 times higher than pure PVC, when the MWCNTs content is 0.054 wt%. MWCNTs can enhance the thermal stability of PVC/ASA blends; the initial decomposition temperature (Tid) and thermal degradation activation energy (Ea) increase by 13.1 °C and 5.7 kJ mol−1, respectively, when the MWCNTs content is 0.066 wt%. The storage modulus (E′) and glass transition temperature (Tg) also increase when MWCNTs are added. MWCNTs can be used as an efficient toughening modifier and processing aid for PVC/ASA blends.

Preparation and characterization of nanocomposite films by hybrid cationic ring opening polymerization of glycidyl-POSS

Co-reporter:Guixiang Hou, Jungang Gao, Cong Tian, Xiaojing Wu

Materials Chemistry and Physics 2014 Volume 148(1–2) pp:236-244

Publication Date(Web):14 November 2014

DOI:10.1016/j.matchemphys.2014.07.040

•Hybrid cationic ring-opening polymerization of the epoxyl-containing POSS (G-POSS).•Preparation of nanocomposites from G-POSS and 3-glycidyloxypropyl-trimethoxysilane.•Reaction kinetics of polymerization was simulated by the Šesták–Berggren model.•Tg and initial decomposition temperature Tid increase 4 and 65 °C respectively.•Microstructure of film is the particle structure which diameter is less than 1.76 nm.Epoxy-polyhedral oligomeric silsesquioxanes (G-POSS) monomers were synthesized from 3-glycidyloxypropyl-trimethoxysilane (GTMS) by hydrolytic condensation. The G-POSS-containing nanocomposite film was prepared by hybrid cationic ring-opening polymerization from G-POSS and GTMS. The curing reaction kinetics, dynamical mechanical properties, thermal degradation properties and morphological structures of G-POSS/GTMS system were investigated by non-isothermal DSC, dynamic mechanical analysis (DMA), TGA, AFM and SEM. The results show that the curing reaction activation energy Ea decrease when GTMS is added into the reaction system, and the curing reaction kinetics can be simulated by the Šesták–Berggren (S–B) model. DMA and TG analysis results show that the glass transition temperature Tg and initial thermal decomposition temperature Tid of materials is 4 and 65 °C higher than pure polymerized G-POSS, respectively, when the content of GTMS is 2 wt%. AFM analysis shows that the membrane surface of pure polymerized G-POSS has uniform distribution of less than 1.76 nm high protrusion. SEM analysis shows that have uniform spherical particle distribution on the membrane surface with about 20–25 nm diameter.In this work, the hybrid cationic ring-opening polymerization of the glycidyl-POSS was investigated and the nanocomposites from glycidyl-POSS and 3-glycidyloxy propyltrimethoxysilane were prepared. This reaction kinetics of polymerization was simulated by the Šesták–Berggren model. The Tg and initial decomposition temperature Tid increase 4.06 and 65 °C than pure glycidyl-POSS polymer respectively. The microstructure of film was characterized by AFM and SEM.

Mechanical and thermal properties of epoxy-POSS reinforced-(biphenyl diol formaldehyde/epoxy hybrid resin) composites

Co-reporter:Shihui Chen;Hongzhe Han;Chao Wang

Iranian Polymer Journal 2014 Volume 23( Issue 8) pp:609-617

Publication Date(Web):2014 August

DOI:10.1007/s13726-014-0255-6

To enhance the properties of epoxy composites, the biphenyl diol formaldehyde resin (BPFR) and glycidyloxypropyl polyhedral oligomeric silsesquioxane (G-POSS) were synthesized and used for modification of fiber-glass reinforced composites of epoxy resin (ER). The BPFR was employed to cure epoxy resin with different G-POSS contents and the laminates of fiber-glass reinforced hybrid composites prepared from BPFR, ER and G-POSS. The dynamic mechanical properties, thermal properties, mechanical and electrical properties of the hybrid composites were characterized by dynamic mechanical analyzer, thermogravimetric analyzer and electroproperty detector. The results showed that the Tg of the composites is increased with the addition of G-POSS. When the content of G-POSS is 5 wt%, the tensile and impact strength of the hybrid composites are 249.87 MPa and 63.83 kJ/m2, respectively, which are all 30 % higher than those of non-added composites. At G-POSS content of 7 wt%, Tg of the material is 9.6 °C higher than pure BPFR/ER composite, and the initial decomposition temperature, Tid, is enhanced by about 29 °C. Dielectric constant, ε, and dielectric loss, tanδ, of the hybrid composites are between 0.53–0.7 and between 0.004–0.012, respectively.

Synthesis and properties of waterborne epoxy acrylate nanocomposite coating modified by MAP-POSS

Co-reporter:Jungang Gao, Hongqiu Lv, Xuefang Zhang, Hongchi Zhao

Progress in Organic Coatings 2013 Volume 76(Issue 10) pp:1477-1483

Publication Date(Web):October 2013

DOI:10.1016/j.porgcoat.2013.06.006

Dynamic rheological behavior and mechanical properties of PVC/CPE/MAPPOSS nanocomposites

Co-reporter:Yonggang Du;Jianbo Yang;Xiaoqian Liu

Journal of Applied Polymer Science 2013 Volume 129( Issue 1) pp:174-180

Publication Date(Web):

DOI:10.1002/app.38719

Abstract

Poly(vinyl chloride)/chlorinated polyethylene (PVC/CPE)/methylacryloylpropyl-containing polyhedral oligomeric silsesquioxane (MAP–POSS) nanocomposites are prepared. The plastic behavior and dynamic rheological behavior of PVC/CPE/MAP–POSS are investigated. The influences of composition on dynamic storage modulus G′, loss modulus G″, and complex viscosity η* of PVC/CPE/MAP–POSS melts are discussed. The dynamic mechanical properties, mechanical properties, and morphology are determined. The results show that both plastic time and balance torque of the nanocomposites decrease, but the G′, G″, and η* all increase with increasing MAP–POSS content. The maximum value of the dynamic mechanical loss tan δ decreases and elasticity increases when MAP–POSS is added. The impact strength of the nanocomposites increases with increasing MAP–POSS content and has the best value at 10% content of MAP–POSS, which is 5.38 kJ/m² higher than that of the blend without MAP–POSS. The MAP–POSS can be used as an efficient process aid and impact aid for the PVC/CPE blend. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Non-isothermal crystallization kinetics of polypropylene/MAP-POSS nanocomposites

Co-reporter:Jungang Gao;Xinxin Cao;Chong Zhang;Wentao Hu

Polymer Bulletin 2013 Volume 70( Issue 7) pp:1977-1990

Publication Date(Web):2013 July

DOI:10.1007/s00289-013-0907-2

Non-isothermal crystallization kinetics of polypropylene (PP)/methylacryloypropy polyhedral oligomeric silsesquioxanes (MAP-POSS) nanocomposites (PP/MAP-POSS) were investigated by DSC at various cooling rates. Jeziorny and Mo method were used to study the non-isothermal crystallization kinetics. The results show that the Jeziorny and Mo method are all successful in describing the non-isothermal crystallization kinetics of PP/MAP-POSS nanocomposites. The MAP-POSS can act a role of heterogeneous nucleation and increase the crystallization rate constant Zc and decrease crystallization half time t1/2, and the spherulite crystal size decreases, the inter-spherulitic action or crosslinking structure each other appear at the appropriate content. The DSC peak temperature Tp increase about 5 °C, t1/2 reduce 0.21 min at 6 % content of MAP-POSS and heating rate of 10 °C/min. The MAP-POSS can also increase the mechanical property of PP/MAP-POSS nanocomposites, the tensile strength and impact strength increase from 12.97 to 19.93 MPa and from 33.2 to 52.6 kJ/m2, respectively, at 4 % content of MAP-POSS. But the spherulitic crystal becomes larger and boundaries become clearer again; the macrophase separation will occur and mechanical properties decrease when more and more MAP-POSS was added. The nanocomposite has the best mechanical property at 4 % content of MAP-POSS.

Hybrid free radical-cationic thermal polymerization of methylacryloylpropyl-POSS/epoxy resins nanocomposites

Co-reporter:Gui-xiang Hou;Jun-gang Gao;Cong Tian

Journal of Polymer Research 2013 Volume 20( Issue 8) pp:

Publication Date(Web):2013 August

DOI:10.1007/s10965-013-0221-6

Methylacryloylpropyl polyhedral oligomeric silsesquioxanes (MAP-POSS) was prepared from methylacryloyloxypropyl three methyl silane (MAPTMS) by hydrolytic condensation. The hybrid cationic thermal polymerization of MAP-POSS with bisphenol-A epoxy resin (E-51) using diphenyliodonium fluoride-borate (DPI·BF4) as a cationic initiator and benzoyl peroxide (BPO) as co-initiator were investigated by the DSC and FTIR. The dynamic mechanical properties of MAP-POSS/E-51 nanocomposites were characterized by DMA. The results showed that polymerization of MAP-POSS/E-51 are the double hybrid free radical/cationic polymerization. The hybrid cationic polymerizing mechanism and curing kinetics could be simulated by the autocatalytic Šesták-Berggren(S-B) model. The cationic ring-opening average activation energy Ea decrease with added MAP-POSS, when 0, 2, 6, and 10 wt.% MAP-POSS were added into reaction system, the curing reaction Ea of sample is 96.53, 95.16, 93.98, 89.15 kJ/mol, respectively. The glass transition temperature Tg of 8 wt.% MAP-POSS containing sample is 175.6 °C, which is 6.1 °C higher than the pure E-51 resin.

Dynamic rheological behavior and mechanical properties of PVC/ACS blends

Co-reporter:Jungang Gao;Jianbo Yang;Yonggang Du;Xiaoqian Liu

Iranian Polymer Journal 2013 Volume 22( Issue 4) pp:285-292

Publication Date(Web):2013 April

DOI:10.1007/s13726-013-0127-5

In order to increase the processability and mechanical properties of poly(vinyl chloride) (PVC), the terpolymer of acrylonitrile-chlorinated polyethylene-styrene (ACS) is used to modify the PVC. The plasticizing, rheological, and dynamic mechanical properties of PVC/ACS blends are investigated by means of torque rheometer, oscillation rheometer, and dynamic mechanical analyzer. The measurements of torque rheometer showed that both plasticizing time and stabilization torque are decreased with increasing ACS content. The PVC/ACS melts displayed larger dynamic storage modulus (G′), loss modulus (G′′), and complex viscosity (η*) than that of pure PVC, and these values reached maximum for the blend with 10 wt% ACS. When ACS content was below 10 wt%, PVC and ACS showed good compatibility in the blends by displaying a single Tg; however, when ACS content was more than 15 wt%, the phase separation phenomena occurred in the blends. PVC/ACS blends showed larger storage modulus (E′) and loss modulus (E′′) than that of pure PVC, but these values decreased with increasing ACS content. ACS can enhance both tensile and impact strength of PVC, and the impact strength reached maximum with 15 wt% ACS content which is higher 2.5 kJ/m2 than the pure PVC. These results suggested that ACS is an efficient processing aid and toughening modifier for PVC at appropriate content.

Kinetics of thermal degradation of nanometer calcium carbonate/linear low-density polyethylene nanocomposites

Co-reporter:Xinxin Cao;Xin Dai;Yufei Liu;Xiaofang He

Journal of Applied Polymer Science 2012 Volume 126( Issue 3) pp:1159-1164

Publication Date(Web):

DOI:10.1002/app.36949

Abstract

To improve the thermal properties of linear low-density polyethylene (LLDPE), the CaCO₃/LLDPE nanocomposites were prepared from nanometer calcium carbonate (nano-CaCO₃) and LLDPE by melt-blending method. A series of testing methods such as thermogravimetry analysis (TGA), differential thermogravimetry analysis, Kim-Park method, and Flynn-Wall-Ozawa method were used to characterize the thermal property of CaCO₃/LLDPE nanocomposites. The results showed that the CaCO₃/LLDPE nanocomposites have only one-stage thermal degradation process. The initial thermal degradation temperature T₀ increasing with nano-CaDO₃ content, and stability of LLDPE change better. The thermal degradation activation energy (E_a) is different for different nano-CaCO₃ content. When the mass fraction of nano-CaCO₃ in nanocomposites is up to 10 wt %, the nanocomposite has the highest thermal degradation E_a, which is higher (28 kJ/mol) than pure LLDPE. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Dynamic rheological behavior and mechanical properties and of PVC/ASA blends

Co-reporter:Yong-gang Du;Jun-gang Gao;Jian-bo Yang;Xiao-qian Liu

Journal of Polymer Research 2012 Volume 19( Issue 11) pp:

Publication Date(Web):2012 November

DOI:10.1007/s10965-012-9993-3

Poly (vinyl chloride) (PVC)/acrylonitrile-styrene-acrylate resin (ASA) blends were proposed in this paper. Plastic and dyanmic rheology behavior of melts were investigated. The influences of composition on storage modulus G′, loss modulus G′′ and complex viscosity η* were discussed. The dynamic mechanical properties, mechanical properties and morphology were determined. The results showed that both the plastic time and balance torque of the blends decreased. The G′, G′′ and η* of PVC/ASA melts all exhibited a monotonic change with increasing frequency and ASA content. The η* of melts was all higher than that of pure PVC. When ASA content in the blend was not over 10 wt.%, both the impact and tensile strength of the blends were increased. The blend had the best impact strength at 10 % content of ASA, which is 4.8 kJ/m2 higher than pure PVC. ASA can be used as an efficient impact aid of PVC at appropriate content, but also can decrease the balance torque and plastic time in the processing.

Reaction kinetics and physical properties of unsaturated polyester modified with methylacyloxylpropyl-POSS

Co-reporter:Jun-gang Gao;Shi-rong Li;De-juan Kong

Journal of Polymer Research 2011 Volume 18( Issue 4) pp:621-626

Publication Date(Web):2011 July

DOI:10.1007/s10965-010-9456-7

The polyhedral oligomeric silsesquioxanes which contains methylacryloylpropyl group (MAP-POSS) was synthesized and used to modify unsaturated polyester resin (UPR). The cure kinetics was investigated by isothermal DSC technique. The mechanical and electrical properties of fiberglass-reinforced laminate were determined. The result shows that the reaction can be described by a Kamal autocatalytic model which has two reaction rate constants k1 and k2, and two apparent activation energies Ea1 and Ea 2 are 98.12 kJ/mol and 74.01 kJ/mol, respectively. UPR and MAP-POSS can co-cure in free radical polymerization. When the MAP-POSS content is 5 wt%, the impact and tensile strength of fiberglass-reinforced laminate enhanced 10% and 6%, respectively, and has better electrical properties than no MAP-POSS. The dielectric constant ε and dielectric loss tanδ are all decrease. The surface resistance ρs is 4.7 times higher than pure UPR laminates