Preparation of cross-linked PVC-g-(St-MA) copolymer/organoclay nanocomposites and investigation of chemical characteristics, morphology, thermal, and mechanical properties

Abstract

The goal of this work is to investigate the effect of incorporating organoclays on the cross-link structure, morphology, and thermomechanical properties of cross-linked organoclay/polyvinyl chloride grafted with styrene and maleic anhydride (PVC- g-(St-MA)) copolymer nanocomposites (CPN). Cloisite30B (C30B) and Cloisite15A (C15A) organoclays were used for the preparation of cross-linked PVC- g-(St-MA) nanocomposites by the solution mixing route. The nanoclay content in nanocomposites varied from 0.2 wt% to 1 wt%. The chemical structure and interaction between PVC- g-(St-MA) cross-linked segments and nanoclays were studied by Fourier transform infrared (FTIR) peaks deconvolution method. FTIR spectroscopy suggested the lowest extent of hydrogen bonding interaction for C30B containing sample, which decreased with clay content increment. The morphology of nanocomposites was studied by X-ray diffraction and transmission electron microscopy methods. Morphological observation revealed a near to the exfoliation state for organoclays in PVC- g-(St-MA) nanocomposite containing 1 wt% C30B. However, C15A/PVC- g-(St-MA) nanocomposite (C15A-CPN) exhibited partially intercalated and agglomerated morphology. Differential scanning calorimetry examination was conducted to measure the glass transition temperature ( T g) of the segments. At the same clay content, the T g of the C30B containing nanocomposites were higher than that of C15A samples. The mechanical properties of these nanocomposites were also investigated. As a consequence, C30B-CPN showed improved mechanical properties compared to C15A-CPN and cross-linked PVC- g-(St-MA) samples.

Clay-reinforced PVC composites and nanocomposites

“…Stirring, shear mixing, and ultrasonication are the agitation forces that facilitate clay dispersion in the polymer solution. In the final step, the solvent is removed, leading to the reassembling of the polymer-intercalated clay and the nanocomposite formation [ 49 , 95 , [103] , [104] , [105] , [106] , [107] , [108] , [109] , [110] ]. It is noteworthy that the solvent evaporation rate is critical to the quality of the composite films.…”

“…The position, shape, and intensity of XRD peaks reveal the structural variation of the nanocomposites. For example, complete delamination of clay is reflected by the disappearance of XRD peaks [ 121 ], while intercalation results in the shift of XRD peaks to lower angles and a decrease in peak intensity [ 49 , 110 , 113 , 122 , 123 ]. Fig.…”

The effect of formulation and processing parameters on thermal stability of PVC/Poly(epichlorohydrin-co-ethylene oxide)/organoclay nanocomposites prepared by melt mixing

“…This salt can easily release HCl gas at high temperatures and results in self-catalyzed degradation of PVC. [7][8][9] Therefore, introducing a formulation for improving thermal stability of PVC/clay nanocomposites has become a challenging topic during the past several decades. Zheng et al used some stabilizers including organotin, calcium/zinc, barium/zinc, and an epoxy co-stabilizer and showed that the combination of the organotin stabilizer and the epoxy co-stabilizer was effective for this purpose.…”

Physico-mechanical properties and cell microstructure of cross-linked PVC/organoclay nanocomposite foams prepared at various processing conditions

“…1 Low price, high processability with additive materials, self-extinguishability, and great fire and chemical resistances are some of the excellent features of PVC which lead it to extensively be used in various fields, such as automobile, packing, and pipe preparation. 2,3 Among PVC-based productions, PVC foams, in addition to the aforementioned properties, possess high strength-to-weight ratios and low water absorption content. 4 PVC foams are widely employed as a core in sandwich-structured composites in different applications, including wind energy, aerospace, transportation and industrial applications, which require damage tolerance and weight loss.…”

“…13–15 One of the most commonly used nanofillers in the preparation of nanocomposite C-PVC foams is the exfoliated and intercalated layers of montmorillonite layered silicate (MLS), such as montmorillonite (MMT) clay with layered silicate structure, which belongs to dioctahedral smectite. 2,16 Due to their high aspect ratio, the layered silicate sheets have a large contact surface with foam matrix which improves C-PVC’s performance. The dispersion and delamination degrees of layered silicate directly control their effectiveness on C-PVC’s properties and the most ideal state could be achieved by a uniform distribution of exfoliated structure throughout the foam matrix.…”