Thermo-mechanical properties of MWCNT-g-poly (l-lactide)/poly (l-lactide) nanocomposites

Amirian, Maryam; Chakoli, Ali Nabipour; Sui, Jie; Cai, Wei

doi:10.1007/s00289-013-0984-2

Cited by 14 publications

(12 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In contrast to the pristine CHWs, the g-CHWs to the crystalline phase of PLLA, as can be seen in Fig. 4 [38,39].…”

Section: Tablementioning

confidence: 84%

“…For the resulting CHW/PLLA and g-CHW/PLLA nanocomposite films, the three diffraction peaks of the PLLA matrix,as mentioned above, shifted slightly to a higher 2θ. This suggested that the crystalline structure of the PLLA matrix may be transformed from α` to α in the CHW/PLLA and g-CHW/PLLA nanocomposite films due to the heterogeneous nucleation effects of CHWs and g-CHWs[38,44]. Additionally, when the content of the CHWs and g-CHWs increased to 10%, the XRD patterns for CHW/PLLA and g-CHW/PLLA nanocomposite films showed an increase in the intensity of the diffraction peak (203), which may be the result of the overlap between the diffraction peaks of the PLLA matrix (203) and the CHWs (110).…”

mentioning

confidence: 97%

See 1 more Smart Citation

Nanocomposites of poly( l -lactide) and surface-modified chitin whiskers with improved mechanical properties and cytocompatibility

Liu

Luo

et al. 2016

European Polymer Journal

View full text Add to dashboard Cite

“…In contrast to the pristine CHWs, the g-CHWs to the crystalline phase of PLLA, as can be seen in Fig. 4 [38,39].…”

Section: Tablementioning

confidence: 84%

mentioning

confidence: 97%

Nanocomposites of poly( l -lactide) and surface-modified chitin whiskers with improved mechanical properties and cytocompatibility

Liu

Luo

et al. 2016

European Polymer Journal

View full text Add to dashboard Cite

“…As discussed in our previous paper , for amorphous polymers, the constrained volume fraction ( φ c ) of PLLA chains around nanoparticles could be estimated by the tan δ values at the glass transition temperature. This constrained region did not contribute to dissipate energy and could be expressed in terms of the ratio between the energy loss of the composite ( H c ) and the neat polymer ( H 0 ) :

φ_{normalc} = 1 - \frac{H_{normalc}}{H_{0}}

where

H = \frac{π \tan δ}{π \tan δ + 1}

…”

Section: Resultsmentioning

confidence: 99%

Rigid amorphous phase and constrained polymer chains in poly(L‐lactide) nanocomposites with carboxylated carbon nanotubes prepared via reactive melt mixing

et al. 2018

View full text Add to dashboard Cite

Evaluation of constrained polymer chains and the glass transition behavior of the nanocomposite constituted by poly(L‐lactide) (PLLA) and functionalized carbon nanotubes (f‐CNTs) have been carried out. To control thermal degradation, nanocomposites were prepared via reactive melt mixing taking advantage of the capacity of carboxylic groups of both PLLA and f‐CNTs to participate in chain extension reactions. At low f‐CNT content (e.g., 0.2 and 0.5 wt%), a good dispersion of f‐CNTs was observed due to scarce bonds established between both components (i.e., the polymer matrix and the nanofiller), whereas at higher f‐CNT content (e.g., 1 wt%), a greater number of epoxy groups of the chain extender were bonded to carboxyl groups of f‐CNTs, giving rise to a highly significant crosslinking of CNT and a lower molecular weight of PLLA. Crystallinity, glass transition temperature and both the rigid polymer chains and constrained polymer chains were influenced by the dispersion state of f‐CNTs after reactive melt mixing and the thermal history (e.g., cooling rate form the melt) of samples. For evaluation of interphases between poly(lactic acid) and f‐CNTs, a simple method was developed for the considered tube‐like nanoparticles. Specifically, thicknesses of the generated interphases were calculated from DMA experiments. POLYM. COMPOS., 39:E1280–E1293, 2018. © 2018 Society of Plastics Engineers

show abstract

“…However, polymers, and specifically polyurethane, also present drawbacks, such as: low shape recovery stress , low mechanical strength , low‐elastic modulus , low stiffness , and high shape‐recovery time . These drawbacks can be overcome by the addition of a filler capable of improving and tailoring the thermo‐mechanical properties of the polymer matrix . It has been verified that the reduction of the size of the particle filler induces the enhancement of the thermo‐mechanical properties of the composite through the increase of the matrix‐filler contact area.…”

Section: Introductionmentioning

confidence: 99%

“…Besides the improvement in the mechanical and electrical properties of the polymer, these carbon nanofillers also present an excellent thermal conductivity (≈5,000 W/m.K for the graphene ; ≈3,000 W/m.K for the CNT ), which provides an enhancement in the thermal properties leading to a faster thermal response and better heat propagation through the polymeric material which results in a faster and improved shape‐memory effect. The underlying mechanism of CNT performance in the polymers lays in their actuation as nucleating agents, hence improving the crystallinity of the soft segments . Clustering is in the nature of CNTs since they are strongly affected by extensive non‐covalent attractive forces between nanotubes, known as van der Waals forces.…”

Section: Introductionmentioning

confidence: 99%

Thermo‐mechanical characterization of shape‐memory polyurethane nanocomposites filled with carbon nanotubes and graphene nanosheets

Fonseca

Oliveira

2018

Polymer Composites

View full text Add to dashboard Cite

The shape‐memory materials are nowadays an important subject in the scientific community due to their huge technological potential. In the present study, in order to pursue the mechanical reinforcement and improvement of the shape‐memory thermoplastic polyurethane (TPU) properties, it was conducted an experimental study in which TPU nanocomposites containing carbon based nanoparticles were produced by melt mixing and injection molding. The resulting nanocomposites contained treated and non‐treated multiwalled carbon nanotubes and graphene. A morphological, thermal and mechanical characterization was performed and in all the samples tested an enhancement on the thermo‐mechanical properties could be observed whenever the pure TPU was concerned. The thermal characterization performed enables to observe that carbon like reinforcement contributes positively to a better heat transfer diffusion. Furthermore, graphene seems to be the most promising reinforcement, when assessing solely the mechanical properties of the obtained nanocomposites. Overall, carbon like reinforcement at the nanoscale on a TPU matrix seems to enhance the shape‐memory ability of the pure TPU material. Nevertheless, the latter requires further insight. POLYM. COMPOS., 39:E1216–E1223, 2018. © 2018 Society of Plastics Engineers

show abstract

Thermo-mechanical properties of MWCNT-g-poly (l-lactide)/poly (l-lactide) nanocomposites

Cited by 14 publications

References 23 publications

Nanocomposites of poly( l -lactide) and surface-modified chitin whiskers with improved mechanical properties and cytocompatibility

Nanocomposites of poly( l -lactide) and surface-modified chitin whiskers with improved mechanical properties and cytocompatibility

Rigid amorphous phase and constrained polymer chains in poly(L‐lactide) nanocomposites with carboxylated carbon nanotubes prepared via reactive melt mixing

Thermo‐mechanical characterization of shape‐memory polyurethane nanocomposites filled with carbon nanotubes and graphene nanosheets

Contact Info

Product

Resources

About