Crystallization kinetics, morphology, and hydrolytic degradation of novel bio‐based poly(lactic acid)/crystalline silk nano‐discs nanobiocomposites

Patwa, Rahul; Kumar, Amit; Katiyar, Vimal

doi:10.1002/app.46590

Cited by 17 publications

(20 citation statements)

References 62 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thermal data such as glass transition temperature ( T g ), cold crystallization temperature ( T cc ), enthalpy of crystallization (Δ H cc ), melting temperature ( T m ), enthalpy of fusion (Δ H m ), and percentage crystallinity (% X c ) from the second heating cycle were reported. The percentage crystallinity was calculated as per

% X_{c} = \frac{\frac{{Δ H}_{normalm} - {Δ H}_{cc}}{{Δ H}_{m}^{°}}}{93.7 ((), 1 - \frac{% wt of filler}{100})} \times 100

…”

Section: Experimental Methodologymentioning

confidence: 99%

“…To evaluate the effect of OLLA‐ g ‐BC fillers on the crystallization process, relative crystallization ( X t ) with respect to time can be calculated according to the

X_{t} = \frac{{Δ H}_{t}}{{Δ H}_{\infty}} = \frac{\int_{0}^{t} ((), \frac{d H}{d t}) normald t}{\int_{0}^{t_{\infty}} ((), \frac{d H}{d t}) normald t}

where, Δ H t , Δ H ∞ , and

\frac{normald H}{normald t}

are enthalpies at any time t , at complete crystallization, and heat evolution rate, respectively.…”

Section: Experimental Methodologymentioning

confidence: 99%

“…

X_{t} = \frac{{Δ H}_{t}}{{Δ H}_{\infty}} = \frac{\int_{0}^{t} ((), \frac{d H}{d t}) normald t}{\int_{0}^{t_{\infty}} ((), \frac{d H}{d t}) normald t}

where, Δ H t , Δ H ∞ , and

\frac{normald H}{normald t}

are enthalpies at any time t , at complete crystallization, and heat evolution rate, respectively. Furthermore, Avrami theory [] is applied for understanding the isothermal crystallization behavior of PLA and bionanocomposite films . The main assumption of this theory is that relative crystallinity increases with increase in crystallization time.

1 - X_{t} = \exp ((), - {Kt}^{n})

…”

Section: Experimental Methodologymentioning

confidence: 99%

“…For PLA to be able to replace conventional packaging plastics, extensive improvement in its barrier and thermomechanical properties is required. To achieve material properties comparable to other benchmark packaging plastics, various strategies are devised such as stereo‐complexation, blending, addition of nano‐ and micro‐fillers, and so on . Reinforcement of PLA matrix by addition of fillers such as cellulose nanocrystals, chitosan, gum, hydroxyapatite, silk, and so on can be used to form bionanocomposites with the desired properties for packaging .…”

Section: Introductionmentioning

confidence: 99%

“…Superiority of filler reinforced polymer bionanocomposites is dictated by dispersion and interfacial adhesion. Therefore, dispersion of filler particles inside the polymer matrix becomes a key factor for nanocomposite properties . The filler dispersion can be improved by numerous techniques such as grafting, sonication, compounding, in situ polymerization .…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Biocomposites of poly(lactic acid) and lactic acid oligomer‐grafted bacterial cellulose: It's preparation and characterization

Patwa

Saha

Sáha

et al. 2019

J of Applied Polymer Sci

Self Cite

View full text Add to dashboard Cite

This work demonstrates the synthesis of lactic acid oligomer-grafted-untreated bacterial cellulose (OLLA-g-BC) by in situ condensation polymerization which increased compatibilization between hydrophobic poly(lactic acid) (PLA) and hydrophilic BC, thus enhancing various properties of PLA-based bionanocomposites, indispensable for stringent food-packaging applications. During the synthesis of OLLA-g-BC, hydrophilic BC is converted into hydrophobic due to structural grafting of OLLA chains with BC molecules. Subsequently, bionanocomposites films are fabricated using solution casting technique and characterized for structural, thermal, mechanical, optical, and gas-barrier properties. Morphological images showed uniform dispersion of BC nanospheres in the PLA matrix, which shows strong filler-matrix interaction. The degradation temperatures for bionanocomposites films were above PLA processing temperature indicating that bionanocomposite processing can be industrially viable. Bionanocomposites films displayed decrease in glass transition (T g ) and~20% improvement in elongation with 10 wt % fillers indicating towards plasticization of PLA. PLA/OLLA-g-BC films showed a slight reduction in optical transparency but had excellent UVblocking characteristics. Moreover, dispersed BC act as blocking agents within PLA matrix, reducing the diffusion through the bionanocomposite films which showed~40% improvement in water-vapor barrier by 5 wt % filler addition, which is significant. The reduced T g , improved elongation combined with improved hydrophobicity and water-vapor barrier make them suitable candidate for flexible foodpackaging applications.

show abstract

% X_{c} = \frac{\frac{{Δ H}_{normalm} - {Δ H}_{cc}}{{Δ H}_{m}^{°}}}{93.7 ((), 1 - \frac{% wt of filler}{100})} \times 100

…”

Section: Experimental Methodologymentioning

confidence: 99%

“…To evaluate the effect of OLLA‐ g ‐BC fillers on the crystallization process, relative crystallization ( X t ) with respect to time can be calculated according to the