The recovery of amorphous PET fiber in global chain orientation but nearly random segmental orientation (GOLR) state was studied by the hot shrinkage measurement above the glass transition temperature. The relaxation ...The recovery of amorphous PET fiber in global chain orientation but nearly random segmental orientation (GOLR) state was studied by the hot shrinkage measurement above the glass transition temperature. The relaxation curves in the form of di-exponential decay were acquired and the change of two special times with the variation of treating temperature and residual recovery ratio ' was discussed.展开更多
Two kinds of aliphatic alternating polyesteramide prepolymers were prepared through melt polycondensation from N,N'-bis(2-hydroxyethyl)-adipamide and adipic acid or sebacic acid.Chain extension of them was conduct...Two kinds of aliphatic alternating polyesteramide prepolymers were prepared through melt polycondensation from N,N'-bis(2-hydroxyethyl)-adipamide and adipic acid or sebacic acid.Chain extension of them was conducted with 2,2'-(1,4-phenylene)-bis(2-oxazoline)and adipoyl biscaprolactamate as combined chain extenders.The chain extended polyesteramides(ExtPEAs)were characterized by IR,1H-NMR,differential scanning calorimetry,thermogravimetric analysis,wide angle X-ray scattering,tensile test and enzymatic degradation.The results showed that the ExtPEA(4,m)s were mainly constituted with the diester adipamide alternating units.ExtPEA(4,4)and ExtPEA(4,8)had Tm of 83.8℃and 85.8℃and initial decomposition temperature above 310.0℃.They crystallized similarly as Nylon-66 did and were flexible thermoplastic materials with tensile strength up to 25.64 MPa and strain at break up to 737%.展开更多
Distributed Lagrange Multiplier/Fictitious Domain （DLM/FD） method was employed to simulate the channel flow with polymer suspension. The polymer molecules were modeled as Finitely Extensible Nonlinear Elastic （FENE...Distributed Lagrange Multiplier/Fictitious Domain （DLM/FD） method was employed to simulate the channel flow with polymer suspension. The polymer molecules were modeled as Finitely Extensible Nonlinear Elastic （FENE） chains and FENE chain cluster. The coiled stretched transition of FENE chains was examined and the change in configuration of FENE chains was presented. The average velocity profile of the fully developed channel flow with 64 FENE chains was given and fitted well with the power-law curve. The change of chain cluster configuration was also simulated. These simulations show that DLM/FD method is capable of simulating the motion of not only FENE chain, but also FENE chain cluster.展开更多
基金the National Key Project for Fundamental Research, "Macromolecular Condensed State" of the State Science and Technology Commissi
文摘The recovery of amorphous PET fiber in global chain orientation but nearly random segmental orientation (GOLR) state was studied by the hot shrinkage measurement above the glass transition temperature. The relaxation curves in the form of di-exponential decay were acquired and the change of two special times with the variation of treating temperature and residual recovery ratio ' was discussed.
基金financially supported by the National Natural Science Foundation of China (Nos.50873013 and 21244006)
文摘Two kinds of aliphatic alternating polyesteramide prepolymers were prepared through melt polycondensation from N,N'-bis(2-hydroxyethyl)-adipamide and adipic acid or sebacic acid.Chain extension of them was conducted with 2,2'-(1,4-phenylene)-bis(2-oxazoline)and adipoyl biscaprolactamate as combined chain extenders.The chain extended polyesteramides(ExtPEAs)were characterized by IR,1H-NMR,differential scanning calorimetry,thermogravimetric analysis,wide angle X-ray scattering,tensile test and enzymatic degradation.The results showed that the ExtPEA(4,m)s were mainly constituted with the diester adipamide alternating units.ExtPEA(4,4)and ExtPEA(4,8)had Tm of 83.8℃and 85.8℃and initial decomposition temperature above 310.0℃.They crystallized similarly as Nylon-66 did and were flexible thermoplastic materials with tensile strength up to 25.64 MPa and strain at break up to 737%.
文摘Distributed Lagrange Multiplier/Fictitious Domain （DLM/FD） method was employed to simulate the channel flow with polymer suspension. The polymer molecules were modeled as Finitely Extensible Nonlinear Elastic （FENE） chains and FENE chain cluster. The coiled stretched transition of FENE chains was examined and the change in configuration of FENE chains was presented. The average velocity profile of the fully developed channel flow with 64 FENE chains was given and fitted well with the power-law curve. The change of chain cluster configuration was also simulated. These simulations show that DLM/FD method is capable of simulating the motion of not only FENE chain, but also FENE chain cluster.
