title: Reinforced Mechanical Properties and Tunable Biodegradability in Nanoporous Cellulose Gels: Poly(L-lactide-co-caprolactone) Nanocomposites.
abstract: Incorporation of nanofillers into aliphatic polyesters is a convenient approach to create new nanomaterials with significantly reinforced mechanical properties compared to the neat polymers or conventional composites. Nanoporous cellulose gels (NCG) prepared from aqueous alkali hydroxide/urea solutions can act as alternative reinforcement nanomaterials for polymers with improved mechanical properties. We report a simple and versatile process for the fabrication of NCG/poly(L-lactide-co-caprolactone) (NCG/P(LLA-co-CL) nanocomposites through in situ ring-opening polymerization of L-lactide (LLA) and ε-caprolactone (ε-CL) monomers in the NCG. The volume fraction of the NCG in the nanocomposites was tunable and ranged from 4.5% to 37%. Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) results indicated that P(LLA-co-CL) were synthesized within the NCG and partially grafted onto the surface of the cellulose nanofibrils. The glass-transition temperature (Tg) of the NCG/P(LLA-co-CL) nanocomposites could be altered by varying the molar ratio of LLA/ε-CL and was affected by the volume fraction of NCG. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) images confirmed that the interconnected nanofibrillar cellulose network structure of the NCG was finely distributed and preserved in the P(LLA-co-CL) matrix after polymerization. The dynamic mechanical analysis (DMA) results showed remarkable reinforcement of the tensile storage modulus (E') of the P(LLA-co-CL) nanocomposites in the presence of NCG, especially above the Tg of the P(LLA-co-CL). The modified percolation model agreed well with the mechanical properties of the NCG/P(LLA-co-CL) nanocomposites. The introduction of NCG into the P(LLA-co-CL) matrix improved the mechanical properties and thermal stability of the NCG/P(LLA-co-CL) nanocomposites. Moreover, the NCG/P(LLA-co-CL) nanocomposites have tunable biodegradability and biocompatibility and potential applications in tissue engineering repair, biomedical implants, and packing.
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University , Wuhan, 430072, People's Republic of China.
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University , Wuhan, 430072, People's Republic of China.
authors.forename: Junchao
authors.initials: J
authors.lastname: Huang
authors.affiliation: School of Materials Science and Engineering, South China University of Technology , Guangzhou, 510641, People's Republic of China.
authors.forename: Huichang
authors.initials: H
authors.lastname: Gao
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University , Wuhan, 430072, People's Republic of China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhong
authors.affiliation: School of Materials Science and Engineering, South China University of Technology , Guangzhou, 510641, People's Republic of China.
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Cao
authors.affiliation: Department of Biomedical Engineering, School of Basic Medical Science, Wuhan University , Wuhan, 430071, People's Republic of China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Chen
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University , Wuhan, 430072, People's Republic of China.
authors.forename: Lina
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University , Wuhan, 430072, People's Republic of China.
authors.forename: Jie
authors.initials: J
authors.lastname: Cai
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001672:Biocompatible Materials / Q000737:chemistry*; D001673:Biodegradation, Environmental; D002152:Calorimetry, Differential Scanning; D002208:Caproates / Q000737:chemistry; D002448:Cell Adhesion / Q000502:physiology; D002460:Cell Line; D049109:Cell Proliferation / Q000502:physiology; D002482:Cellulose / Q000737:chemistry*; D004146:Dioxanes / Q000737:chemistry; D005782:Gels / Q000737:chemistry*; D007783:Lactones / Q000737:chemistry; D051379:Mice; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D053761:Nanocomposites / Q000737:chemistry*; D058608:Nanopores; D011091:Polyesters / Q000138:chemical synthesis / Q000737:chemistry*; D058105:Polymerization; D011108:Polymers / Q000737:chemistry; D019736:Prostheses and Implants; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D023822:Tissue Engineering / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D002208:Caproates; D004146:Dioxanes; D005782:Gels; D007783:Lactones; D011091:Polyesters; D011108:Polymers; C121056:caprolactone; C062968:lactide-caprolactone copolymer; D002482:Cellulose; C091880:dilactide