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To develop fully biodegradable and reinforced poly(lactic acid) (PLA) melt-blown nonwovens (MBs) for separation and filtration, PLA/aminated halloysite nanotubes (PLA/A-HNTs) MBs were prepared using PLA/A-HNTs master-batches, compatibilized by dual-monomer glycidyl methacrylate-styrene (St-co-GMA) melt-grafted PLA (PLA-g-(St-co-GMA)). The morphology, crystallization, pore size distribution, filtration performance, and mechanical properties of PLA/PLA-g-(St-co-GMA)/A-HNTs MBs were characterized. The results indicated that PLA/PLA-g-(St-co-GMA)/A-HNT MBs could be successfully manufactured, with well dispersed A-HNTs in PLA MB fibers due to improved compatibility by PLA-g-(St-co-GMA). Incorporation of A-HNTs and PLA-g-(St-co-GMA) slightly increased the average diameter and pore size of PLA MBs. A-HNTs increased the crystallinity degree of PLA MBs, while the crystal forms remained unchanged. In comparison with PLA MBs, the tensile strengths of PLA/PLA-g-(St-co-GMA)/A-HNTs MBs were enhanced but the elongation decreased. PLA/PLA-g-(St-co-GMA)/A-HNT MBs could obtain higher filtration efficiency than neat PLA MBs.

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The emergence of graphene-based polymer composite fibers provides a new opportunity to study the high-performance and functional chemical fibers. In this work, we have developed an efficient and convenient method with polydopamine (PDA) to functionalize and reduce graphene oxide (GO) simultaneously, and the modified graphene nanosheets can obtain uniform dispersion and strong interfacial bonding in nylon 6 (PA6). Furthermore, the reinforced PA6 composite fibers were prepared through mixing PDA-rGO into the PA6 polymer matrix and then melt spinning. The functional modification was characterized by surface analysis and structural testing including SEM, TEM, FTIR, and Raman. When the addition amount of the modified GO was 0.15 wt%, the tensile strength and Young’s modulus of the composite fiber reached 310.4 MPa and 462.3 MPa, respectively. The results showed a meaningful reinforcement with an effect compared to the pure nylon 6 fiber. Moreover, the composite fiber also exhibited an improved crystallinity and thermal stability, as measured by DSC and TGA.

The multifunctional nanohybrid llers have attracted widespread attention in the eld of polymer nanocomposites. In this study, carboxyl cellulose nanocrystals/copper nanoparticles (TCNC/Cu NP) nanohybrids were prepared by in situ growth of copper ions on the modi ed carboxyl CNC, and further doped into waterborne polyurethane (WPU)via solution blending. TEM, FTIR, XRD, and UV-vis analysis were used to characterize the morphology, composition, crystallization and structure of the as-prepared nanohybrid. TCNC/Cu NP nanohybrids exhibited good dispersion and interface compatibility in WPU matrix thanks to the modi ed CNC. The nanocomposite lm obtained signi cantly enhanced mechanical, thermal stability and scratch resistance properties, which was attributed to a hydrogen bond network structure formed in the WPU matrix. Additionally, colony count method was performed to test antibacterial properties of various lms. Compared to the pure WPU lm, all of nanocomposite lms showed good antibacterial properties against Escherichia coli and Staphylococcus aureus. The antibacterial ratio of the WPU nanocomposite lm with the addition of TCNC/Cu NP (1:1) reach 99%. Furthermore, the results of a copper ion sustained release experiment showed that the nanocomposite lm had a long-term release effect, which was ascribe to the strong bonding between TCNC/Cu NP nanohybrids and WPU matrix. Thus, Cu NP was rmly embedded in the hydrogen bonding network structure formed. This work gives a new approach to prepare the antibacterial WPU lm with well mechanical properties.Highlights.docx