| In the first part of this paper, the anionic polymerizationε-caprolactam initiated by activators with different structure at relatively high temperature was investigated. And the polyamide-polysiloxane copolymer was synthesized by the anionic polymerization ofε-caprolactam initiated by the activator modified by polysiloxane. Results show that the ether block of the polysiloxane can improve the compatibility between the polyamide block and polysiloxane block. The introducing of hydrophobic flexible polysiloxane block can improve the water resistance, surface properties and impact toughness of the polyamide-polysiloxane copolymer. However, the experiments on the Haake extruder indicate that it is difficult to realize the preparation of polyamide-polysiloxane copolymer via reactive extrusion for the increased reaction induce time resulted from the effect of polysiloxane chain on the reactivity of the activator.The second part of the paper is focused on the polycaprolactone based polyurethanes. First, the modified titanium alkoxide mixture used for the ring-opening polymerization (ROP) ofε-caprolactone (CL) was synthesized through the ester-exchange reaction of titanium n-propoxide and poly ether diol. The mechanism and kinetics of the bulk polymerization of CL initiated by the modified titanium alkoxide mixture were investigated by DSC and 1H-NMR. The results demonstrate that the polymerization of CL initiated by the modified titanium alkoxide mixture proceeds through the coordination-insertion mechanism and all hydroxyl groups of the polyether share a similar activity in initiating ROP of CL, including the free and potential hydroxyl groups of the polyether. The isothermal polymerization process can be well predicted by the obtained kinetic parameters, and the activation energy is 108-109 KJ/mol. The activation energies of the non-isothermal CL ROP determined by Flynn-Wall, Kissiger and Ozawa methods agree quite well, for Ti(OPEG400)4 and PEG-400 mixture is 55-61 KJ/mol and Ti(OPEG1000)4 and PEG-100069-73 KJ/mol. The ROP of CL initiated by the modified titanium alkoxide mixture can approximately to be 1 order reaction.On the basis of the kinetics for CL ROP, PCLU with multi-block copolymer of polycaprolactone (PCL) and poly(tetramethylene oxide) glycol (PTMG) or polyethylene glycol (PEG) as soft segment was in-situ synthesized via reactive extrusion from CL and 4,4'-diphenylmethane diisocyanate (MDI). The modified titanium alkoxide mixture was utilized as initiator and catalyst. Compared to the reported fabrication of PCLU, the in-situ reactive extrusion preparation not only explored a new rapid route for fabrication of PCLU but also offered a simplified controllable approach for the production of PCLU in a successive mass scale. A series of PTMG-PCLU and PEG-PCLU of different PCL block average degree of polymerization (DPn) were prepared by only adjusting the relative concentration of the CL in the reaction system, with the mole ratio of MDI to titanium alkoxide kept at a certain constant.1H-NMR, GPC and DSC results indicate that all the CL monomers have been converted in the polymerization and the molecular weight of the copolymers is about 8×104 g/mol with a polydispersity index of approximate 2.4. With increasing the PCL block DPn in PTMG-PCLU from 25 to 40, the tensile strength increases from 16.5 MPa to 22.7 MPa, and the melting point increases from 46.1℃to 49.5℃. It was also verified by PEG-PCLU prepared with organic Ti of lowered content in the initiator mixture that the mechanical properties can be greatly affected and dropped with the decrease of the content of organic Ti in the initiator mixture.Since the properties of the PCLU will be affected by the crystallization behavior of the PCL block, to study the effects of the PCL block DPn and the type of polyether block on the PCLU obtained via reactive extrusion, the non-isothermal crystallization kinetics were investigated by DSC. The DSC experiment data was analyzed by a Jeziorny modified Avrami model, Ozawa model, and Mo mixed Avrami-Ozawa model, respectively. The results demonstrate that the non-isothermal crystallization can be well described by the Jeziorny modified Avami model, and Mo mixed model, but Ozawa model can only do for some of the products. The kinetic results indicate that the nucleation and crystal growth for the non-isothermal crystallization of PCLU is complicated, but mainly in a way of a thermal nucleation followed by three-dimensional spherical growth. In the non-isothermal crystallization, the PCL block DPn and the type polyether block does not affect the crystallization mechanism. The activated energy of non-isothermal crystallization decreases with increasing the PCL block DPn.The shape memory properties were investigated in terms of the deformation amplitude, temperature and rate by DSC, DMA and POM. DSC analysis shows that the crystalline melting temperature and crystallinity of PCLU increased monotonically with increasing the PCL block DPn. The retract force increased with increasing the temperature and reached the maximum within 45-55℃. The maximum retract force of PCLU is 6-7 MPa which is as high as that of polylactic acid based polyurethanes. Furthermore, a modified model with two recovery stages was postulated to elucidate the shape memory process, which is visually presented by POM analysis. The two stages of tensile and compressive recovery are distinguished by the inflexion temperature, within 43-48℃and 64-66℃respectively. The temporary shape fixity of the products is about 60-70% and can be improved to 100% by choosing proper deformation temperature. The tensile deformation recovery ratio was 80-98% due to the water absorption, while the compressive deformation recovery ratio was almost 100%. Besides, recovery tests show that the lowest recovery temperature which ranged from 24-47℃was influenced by the deformation temperature, deformation rate, the PCL block DPn and the molecular weight of the polyether diol. Thus, the shape memory properties can be adjusted according to different purposes.
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