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A CO2‐based thermoplastic elastomer, poly(propylene carbonate)‐multiblock‐polyamide6 (PPC‐mb‐PA6) copolymer, was constructed through coupling amorphous/soft PPC blocks with crystalline/hard PA6 blocks. The PPC‐mb‐PA6 copolymers with different block length pairs were designed and synthesized, and then fully characterized by structural, thermal, and mechanical analysis. The proton nuclear magnetic resonance (1H‐NMR), diffusion ordered spectroscopy (DOSY), heteronuclear multiple‐bond correlation (HMBC) and gel permeation chromatography (GPC) results confirm that the multiblock sequence structure of PPC‐mb‐PA6. The differential scanning calorimetry (DSC) tests show that all PPC‐mb‐PA6s possess melting points around 179–206°C. The thermal and mechanical analysis indicates improved service temperatures (T5% up to 270°C) and tensile strength ranging from 15.8 to 39.6 MPa with higher PA6 content. The dynamic mechanical analysis demonstrates excellent shape memory effect of PPC‐mb‐PA6 with thermal stimuli responsiveness derived from the micro phase separation between soft PPC and hard PA6 domains. And the characteristic strain fixity parameter (Rf) and deformation recovery rate (Rr) are 98% and 100%, respectively, which are comparable with other excellent shape memory polymers. [ABSTRACT FROM AUTHOR]

In order to study the influence of freeze–thaw cycles on chloride ion corrosion resistance of RPC with copper slag (CS) instead of quartz sand (QS), the 28d uniaxial compressive strength (UCS) of CSRPC with a different CS substitution rate was investigated by unconfined compression tests. The electric flux test method was used to study the chloride ion diffusion resistance of CSRPC after freeze–thaw cycles, and the pore size distribution was obtained through the nuclear magnetic resonance (NMR) method. Then, a mathematical relationship between the chloride ion diffusion coefficient and the pore fractal characteristic parameter T was established to study the effect of freeze–thaw cycles on chloride ion diffusion. Finally, SEM/EDS, XRD, and DTG methods were combined to study the influence of the distribution of Friedel's salts generated after freeze–thaw cycles on chloride ion diffusion in CSRPC. The results indicate that CS has a micro aggregate effect and pozzolanic activity, which can effectively improve the chloride ion diffusion resistance of CSRPC after freeze–thaw cycles. In addition, the electric flux of CSRPC decreases with the increase in freeze–thaw cycles, and the chloride diffusion coefficient is closely related to the pore fractal dimension. [ABSTRACT FROM AUTHOR]