Modification of biodegradable polylactide by silica and wood flour through a sol–gel process

Abstract

The aim of this work is the production of new biodegradable nanocomposites from polylactide (PLA), tetraethoxysilane (TEOS), and wood flour (WF) by means of an in-situ sol-gel process and a melt blending method. Characterizations of SiO 2 , PLA, and hybrids were performed by FTIR, 29 Si solid-state NMR, XRD, DSC, TGA, and SEM analyses. As the results, the SiO 2 can be well dispersed into the acrylic acid grafted polylactide (PLA-g-AA) in nanoscale sizes since the TEOS is partially compatible with PLA-g-AA and allows PLA-g-AA chains intercalating into SiO 2 layers.29 Si solid-state NMR analysis showed that Si atoms coordinated around SiO 4 units were predominantly Q 3 and Q 4 . The PLA-g-AA/SiO 2 hybrid demonstrates dramatic enhancement in thermal and mechanical properties of PLA; for example, 808C and 20 MPa increases in IDT and TS with the addition of 10 wt % SiO 2 due to the formation of SiÀ ÀOÀ ÀC bond, and the nanoscale dispersion of silicate layers in the polymer matrix. On the basis of the consideration of thermal and mechanical properties, it is also found that 10 wt % of SiO 2 content is optimal for preparation of PLA-g-AA/SiO 2 nanocomposites. The biodegradable nanocomposites produced from our laboratory can provide a plateau tensile strength at break when the WF content is up to 50 wt %.

Preparation and Characterization of Poly(lactic Acid)-based Composite Reinforced with Oil Palm Empty Fruit Bunch Fiber and Nanosilica

“…The main absorbances of the samples appeared at regions of low wavenumber, specifically from 500 cm -1 to 1800 cm -1 . However, characteristic peaks for PLA were observed at the 2800 cm -1 to 3000 cm -1 region (Wu and Liao 2008). The spectrum of OPEFB was similar to that in the work of Siyamak et al (2012), where main peaks are located almost at the same wavenumbers (3340, 2900, 1729, and 1604 cm -1 ).…”

“…Figure 3 shows the spectra of 1.0 wt.% fiber-reinforced PLA with 1.0 wt.% organic or inorganic silica. There was a shift of the broad band (~3500 to 3800 cm -1 ) to the left corresponds to the OH stretching (Wu and Liao 2008). This phenomenon occurred because of the existence of hetero-associated hydrogen bonds that formed between the carboxylic acid groups of PLA and the silica bonded group (Wu and Liao 2008).…”

“…There was a shift of the broad band (~3500 to 3800 cm -1 ) to the left corresponds to the OH stretching (Wu and Liao 2008). This phenomenon occurred because of the existence of hetero-associated hydrogen bonds that formed between the carboxylic acid groups of PLA and the silica bonded group (Wu and Liao 2008). Hydrogen bonding was the only interfacial force that facilitated the interconnection between the PLA matrix and the nanosilica reinforcement network.…”

“…On the other hand, organic silica extracted from bamboo leaves also contained the same functional group at wavenumbers 1051 and 796 cm -1 . The broad band between 3700 and 2800 cm -1 (centered at 3384 cm -1 ) correspond to OH stretching, whereas the peak at 976 cm -1 was assigned to the formation of the Si-OH bond (Wu and Liao 2008). The peak at 1636 cm -1 was attributed to the aromatic skeletal vibrations of lignin.…”

Degradation Classification of 3D Printing Thermoplastics Using Fourier Transform Infrared Spectroscopy and Artificial Neural Networks

“…Song et al [4] reported biodegradable lactic-acid-based telechelic pre-polymers incorporating CNTs characterized by FTIR, TGA, DSC, POM, and so on. Wu and Liao [5] reported the production of new biodegradable nanocomposites from polyactide (PLA), tetraethoxysilane (TEOS), and wood flour (WF) using an in-sihi sol-gel process and a melt blending method. They used FTIR to characterize SiO 2 , PLA, and hybrids.…”