Taking the polycarbonate (PC) as research objective, the migration properties and morphological evolution of polymer chains under three dimensional periodic boundary condition were studied based on molecular dynamics (MD) simulation. And the flow induced orientation mechanism of polymer was revealed by comparing simulated and experimental results. The mean square displacement indicated that the orientation process was actually an coordinated conformation of polymer conglomeration, although the mean square displacement increased largely and the non-bond energy decreased rapidly while the shear rate increasing, the structure of polymer chains did not changed at all. At the same time, the randomly entangled polymer chains not only arranged along flow direction, but also separated from each other and tended to be dispersive distribution. The experimental results showed that birefringence increased with the increase of the injection rate and decreased along the flow direction, while the tensile properties in the orientation direction also increased with the increase of the degree of orientation, which is well consistent with the migration behavior and morphology evolution rules indicated by the simulation results.
Tadmor Z . Molecular orientation in injection molding[J]. Journal of Applied Polymer Science, 1974,18(6):1753.
2
Patcharaphun S, Mennig G . Simulation and experimental investigations of material distribution in the sandwich injection molding process[J]. Polymer-Plastics Technology and Engineering, 2006,45(6):759.
3
Krueger W L, Tadmor Z . Injection molding into a rectangular cavity with inserts[J]. Polymer Engineering & Science, 1980,20(6):426.
4
Jie Z, Hong L, Lei Z , et al. The effects of vibration field on crystal structures and orientation of isotactic polypropylene injection samples[J]. Polymer Bulletin, 2012,68(1):239.
5
Isayev A I . Orientation development in the injection molding of amorphous polymers[J]. Polymer Engineering & Science, 2004,23(23):271.
6
Abbasi S, Carreau P J, Derdouri A . Flow induced orientation of multiwalled carbon nanotubes in polycarbonate nanocomposites: Rheology, conductivity and mechanical properties[J]. Polymer, 2010,51(4):922.
7
Arjmand M, Mahmoodi M, Gelves G A , et al. Electrical and electromagnetic interference shielding properties of flow-induced oriented carbon nanotubes in polycarbonate[J]. Carbon, 2011,49(11):3430.
8
Ozcelik B, Ozbay A, Demirbas E . Influence of injection parameters and mold materials on mechanical properties of ABS in plastic injection molding[J]. International Communications in Heat and Mass Transfer, 2010,37(9):1359.
9
Sadabadi H, Ghasemi M . Effects of some injection molding process parameters on fiber orientation tensor of short glass fiber polystyrene composites (SGF/PS)[J]. Journal of Reinforced Plastics & Compo-sites, 2007,26(17):1729.
10
Tiusanen J, Vlasveld D, Vuorinen J . Review on the effects of injection moulding parameters on the electrical resistivity of carbon nanotube filled polymer parts[J]. Composites Science and Technology, 2012,72(14):1741.
11
Min I, Yoon K . An experimental study on the effects of injection-molding types for the birefringence distribution in polycarbonate discs[J]. Korea-Australia Rheology Journal, 2011,23(3):155.
12
Isayev A I, Lin T H . Frozen-in birefringence and anisotropic shrin-kage in optical moldings: I. Theory and simulation scheme[J]. Polymer, 2010,51(1):316.
13
Katletz S, Pfleger M, Pühringer H , et al. Polarization sensitive terahertz imaging: Detection of birefringence and optical axis[J]. Optics Express, 2012,20(21):23025.
14
Barrat J L, Baschnagel J, Lyulin A . Molecular dynamics simulations of glassy polymers[J]. Soft Matter, 2010,6(15):3430.
15
Mahajan D K, Hartmaier A . Mechanisms of crazing in glassy polymers revealed by molecular dynamics simulations[J]. Physical Review E, 2012,86(1):1818.
16
Venkatesan S, Basu S . Investigations into crazing in glassy amorphous polymers through molecular dynamics simulations[J]. Journal of the Mechanics and Physics of Solids, 2015,77:123.
17
Sommer J U, Luo C . Molecular dynamics simulations of semicrystalline polymers: Crystallization, melting, and reorganization[J]. Journal of Polymer Science Part B Polymer Physics, 2010,48(21):2222.
18
Wang L Z, Duan L L . Isothermal crystallization of a single polyethylene chain induced by graphene: A molecular dynamics simulation[J]. Computational & Theoretical Chemistry, 2012,1002(48):59.
19
Pandiyan S, Rousseau B . Factors influencing properties of interfacial regions in semicrystalline polyethylene: A molecular dynamics simulation study[J]. Polymer, 2013,54(14):3586.
20
Peng Y, Locker C R, Rutledge G C . Molecular dynamics simulation of homogeneous crystal nucleation in polyethylene[J]. Macromolecules, 2013,46(11):4723.
21
Yamamoto T . Molecular dynamics simulations of steady-state crystal growth and homogeneous nucleation in polyethylene-like polymer[J]. Journal of Chemical Physics, 2008,129(18):2732.
22
Hossain D, Tschopp M A, Ward D K , et al. Molecular dynamics simulations of deformation mechanisms of amorphous polyethylene[J]. Polymer, 2010,51(25):6071.
23
Sahputra I H, Echtermeyer A T . Molecular dynamics simulations of strain-controlled fatigue behaviour of amorphous polyethylene[J]. Journal of Polymer Research, 2014,21(11):1.
24
4 Bunte S W, Sun H . Molecular modeling of energetic materials: The parameterization and validation of nitrate esters in the COMPASS force field[J]. The Journal of Physical Chemistry B, 2000,104(11):2477.
25
5 Jie Y, Ren Y, Tian A , et al. COMPASS force field for 14 inorganic molecules, He, Ne, Ar, Kr, Xe, H2, O2, N2, NO, CO, CO2, NO2, CS2, and SO2, in liquid phases[J]. Journal of Physical Che-mistry B, 2000,104(20):4951.
26
6 Andersen, H C . Molecular dynamics simulations at constant pressure and/or temperature[J]. The Journal of Chemical Physics, 1980,72(4), 2384.
27
27 Berendsen H J C, Postma J P M, Gunsteren W F V , et al. Molecular dynamics with coupling to an external bath[J]. Journal of Chemical Physics, 1984,81(8):3684.
28
28 De Gennes P G. Scaling concepts in polymer physics[M].Cornell University Press, 1979.
29
9 Davies M, Clemett C . Molecular dynamics simulations of the chain dynamics in monodisperse oligomer melts and of the oligomer tracer diffusion in an entangled polymer matrix[J]. The Journal of Chemical Physics, 2010,132(19):96.
30
0 Grosse A V . Viscosity and self-diffusion of liquid metals[J]. Science, 1964,145(3627):50.
31
Isayev A I . Orientation development in the injection molding of amorphous polymers[J]. Polymer Engineering & Science, 1983,23(5):271.
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2018, Vol. 32 
