Vanillic acid (VA), an abundant renewable biomaterial derived from lignin, has been employed as a new building skeleton to formulate esters. These esters with different alkyl chains (VA4-Cn) were synthesized, characterized, and used as plasticizers for phthalate-free flexible poly(vinyl chloride) (PVC). Miscibility analysis reveals that VA4-Cn exhibits good miscibility with PVC and that the length of the alkyl chains of VA4-Cn is the key factor for improving its miscibility. The PVC blends of esters derived from vanillic acid display flexibility and stretchability comparable to or better than those of the PVC blend of dioctyl phthalate (DOP). In particular, PVC/VA4-C1 has a 55% higher elongation at break than PVC/DOP. The thermal stability of PVC/ VA4-Cn blends and plasticizer volatility and thermal stability are improved by increasing the alkyl chain length, which may be explained by an increase in the molecular weight. However, the leaching in n-hexane increases with increasing alkyl chain length due to the increased nonpolarity of the plasticizer. Nevertheless, in terms of glass transition temperature reduction, VA4-Cn demonstrated a plasticizing performance that was comparable to or better than that of DOP. In particular, good plasticization was achieved when VA4-C1 was used. The plasticizing effect is excellent without any phase separation at high concentrations. These results suggest that VA4-Cn has great potential as a biobased alternative to traditional phthalate plasticizers.

This Article reports the facile fabrication of robust and durable superhydrophobic and superoleophilic cotton for highly efficient oil–water separation based on the combination of hydrophobic octadecanoyl chain bonding and polymer grafting via surface-initiated atom transfer radical polymerization (SI-ATRP). Octadecanoyl chain-tethered and polymer-grafted superhydrophobic cotton was obtained by simultaneous treatment with stearoyl chloride and α-bromoisobutyryl bromide to generate hydrophobic cotton bearing initiating sites for ATRP (C18-Cotton-Br), followed by SI-ATRP of acrylonitrile and styrene to obtain polymer-grafted cotton (C18-Cotton-g-PSAN). The surface morphologies, chemical composition, and structural identity of the modified cotton were investigated by scanning electron microscopy (SEM), FT-IR, X-ray photoelectron spectroscopy (XPS), and the nitrogen physisorption experiments. The water contact angle (WCA), oil–water separation, oil absorption, and mechanical properties of the cotton samples were evaluated systematically. The results showed that octadecanoyl and α-bromoisobutyryl groups were successfully bonded on pristine cotton to exhibit hydrophobicity, and further polymer grafting of PSAN was realized with a high grafting density of about 0.47 nm–2. Compared with C18-Cotton-Br, after polymer grafting C18-Cotton-g-PSAN displayed enhanced superhydrophobicity with the WCA increasing from 154° to 159° due to the increased surface roughness. C18-Cotton-g-PSAN exhibited a highly efficient oil–water separation achieving 99.2%, excellent absorption capacity of 26 g/g for toluene with an easily recovered performance, and remarkable mechanical durability withstanding the severe environmental conditions. The biodegradable and recyclable C18-Cotton-g-PSAN demonstrated high selectivity for the absorbing of oil and is expected to become sustainable and highly effective materials for oil-spill cleanup and the oily wastewater treatment from households and industries. Endowed with the robust superhydrophobic durability, the superhydrophobic and superoleophilic cotton can be further woven into cotton fabric to demonstrate their versatilities.

A series of tartaric acid (TA) esters with different side chain lengths [dibutyl TA esters (DBTAE)-Cn], as plasticizers for poly(vinyl chloride) (PVC), is herein reported. Their structures have been fully characterized using proton nuclear magnetic resonance and Fourier-transform infrared spectroscopy. Their compatibility and plasticizing effect for soft PVC were evaluated using thermogravimetric analysis, dynamic mechanical analysis, tensile testing, and migration testing. The results showed that all these TA esters exhibit good plasticizing performance. At a concentration of 30 phr in PVC, the best results for the plasticizing effect, in terms of glass transition temperature reduction and elongation at break, were achieved when the ester DBTAE-C4 was used. However, the longer side chains of these esters improved the thermal stability of soft PVC blends yet exacerbated the migration behavior of these esters from PVC films in n-hexane. The properties of the plasticized PVC blends depended on the structural features of DBTAE-Cn. The plasticizing performances of the esters DBTAE-C1 and DBTAE-C4 rivaled that of dioctyl phthalate (DOP), suggesting that they have the potential to replace DOP in soft PVC materials.

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