Suspension polymerization of vinyl chloride (VCM) was carried out in the presence of particle of both pristine Mg-Al layered double hydroxide (LDH) and LDH intercalated by 3-(trimethoxysilyl) propyl methacrylate (MPTMS-LDH) in a pilot-scale reactor. The experiments were conducted at different concentrations of each type of the particles (0, 1, 3, 5, 7 wt. % of VCM). The pure LDH and MPTMS-intercalated LDHs were used as co-monomer for fabrication of LDH or MPTMS-LDH/PVC nanocomposites; the particles were directly pre-dispersed in monomer phase before dispersing in the continuous aqueous phase and starting the suspension polymerization. The basal spacing obtained from the X-ray powder diffraction (XRD) showed that the reaction between VCM and MPTMS-LDH was effective, with a further intercalation of PVC chains in the interlayer space. The molecular characterization showed that the polydispersity index (PDI) and molecular weight of the poly (vinyl chloride) (PVC) resin do not change in the presence of the pristine LDH. The MPTMS-LDH, however, decrease the molecular weight and increase the PDI of PVC resin. Also, from the morphological point of view, scanning electron microscopy (SEM) showed that PVC grains produced with high particles content had a smoother surface with more regular shape. Moreover the incorporation of nanoparticles in the VCM suspension polymerization, made particles with a narrower size distribution. The LDH results in the formation of smaller primary particles with higher internal porosity whereas, the larger primary particles with lower internal porosity in the presence of modified particles was observed.
A series of poly (vinyl chloride) (PVC) composites have been madethrough an in-situ suspension polymerization process in attendanceof 5 wt% of MgAl(NO3) layered double hydroxide (LDH) or 3-(trimethoxysilyl) propyl methacrylate (MPTMS)-intercalated Mg-AlLDH (MPTMS-LDH). The thermal stability and mechanical and phys-ical properties of the prepared composite samples were examined andcompared with the pure PVC. The data obtained from the Brabender®plastograph illustrated that the final PVC grains prepared in atten-dance of MPTMS-LDH have higher thermal stability time and lowerfusion. The fusion degree of PVC particles has been incremented byMPTMS-LDH nanosheet; as a result, it has been observed that alower requirement of temperature/time process. A conventional dehy-drochlorination test proved the improvement of thermal stability. The composite, including MPTMS-LDH, showed a 40% improvement indehydrochlorination rate relative to the pure PVC, this enhance-ment is 12% in comparison with PVC/LDH composite. TGA curvesshow that the 5 and 50% weight loss temperatures of PVC resinshave remarkable growth (∼11 ◦C) with introducing 5 wt% LDH orMPTMS-LDH. The storage modulus of the glassy state(glassy plato)and the Tg of the PVC/MPTMS-LDH is higher than the pure PVCand composite of PVC/LDH. The results of mechanical analysis illus-trated that PVC/LDH-MPTMS composites have larger stiffness andtoughness. The Charpy notched impact strength, tensile strength, andYoung’s modulus of the PVC/LDH-MPTMS composites are signifi-cantly more than the composite of PVC/LDH and the pure PVC.
A series of PVC composites were produced using an in-situ suspension polymerization method with an optimal amount of 5 wt% of MgAl(NO3) layered double hydroxide (LDH) or LDH-MPTMS, which is MPTMS-intercalated Mg-Al LDH. The physical, mechanical, and thermal properties of the composite samples were compared to pure PVC. Results from the Brabender® plastograph showed that the PVC grains produced with LDH-MPTMS had a longer thermal stability time and shorter fusion time. The addition of LDH-MPTMS nanosheets increased the gelation degree of PVC particles, resulting in a lower temperature/time requirement for processing. The thermal stability of the composite material was confirmed through a standard dehydrochlorination test, which demonstrated a 40% improvement in dehydrochlorination rate compared to pure PVC. This improvement was 12% higher than that observed in the PVC/LDH composite. TGA curves indicated a significant increase in the 5 and 50% weight loss temperatures of PVC resins with the addition of 5wt% LDH or LDH-MPTMS, with an approximate growth of 11°C. The glassy state storage modulus and Tg of the PVC/LDH-MPTMS composite were higher than those of pure PVC and the PVC/LDH composite. Mechanical analysis revealed that the PVC/LDH-MPTMS composites exhibited greater stiffness and toughness, as well as significantly higher Charpy notched impact strength, tensile strength, and Young’s modulus compared to both the PVC/LDH composite and pure PVC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.