Preparation, structure, and properties of poly(vinyl acetate-co-methyl methacrylate) nanocomposite microspheres with exfoliated montmorillonite through using two-stage in situ suspension polymerization

2013 ◽  
pp. n/a-n/a
Author(s):  
Jingshui Xu ◽  
Yangchuan Ke ◽  
Qian Zhou ◽  
Xianglong Hu ◽  
Zijuan Tan ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Vinyl Acetate ◽  
Suspension Polymerization ◽  
Structure And Properties ◽  
Two Stage

scholarly journals Combined Chemical Modification of Bamboo Material Prepared Using Vinyl Acetate and Methyl Methacrylate: Dimensional Stability, Chemical Structure, and Dynamic Mechanical Properties

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1651 ◽  
Author(s):  
Saisai Huang ◽  
Qiufang Jiang ◽  
Bin Yu ◽  
Yujing Nie ◽  
Zhongqing Ma ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Chemical Modification ◽  
Methyl Methacrylate ◽  
Vinyl Acetate ◽  
Dimensional Stability ◽  
Chemical Structure ◽  
In Situ Polymerization ◽  
Dynamic Mechanical Properties

Acetylation and in situ polymerization are two typical chemical modifications that are used to improve the dimensional stability of bamboo. In this work, the combination of chemical modification of vinyl acetate (VA) acetylation and methyl methacrylate (MMA) in situ polymerization of bamboo was employed. Performances of the treated bamboo were evaluated in terms of dimensional stability, wettability, thermal stability, chemical structure, and dynamic mechanical properties. Results show that the performances (dimensional stability, thermal stability, and wettability) of bamboo that was prepared via the combined pretreatment of VA and MMA (VA/MMA-B) were better than those of raw bamboo, VA single-treated bamboo (VA-B), and MMA single-treated bamboo (MMA-B). According to scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analyses, VA and MMA were mainly grafted onto the surface of the cell wall or in the bamboo cell lumen. The antiswelling efficiency and contact angle of VA/MMA-B increased to maximum values of 40.71% and 107.1°, respectively. From thermogravimetric analysis (TG/DTG curves), the highest onset decomposition temperature (277 °C) was observed in VA/MMA-B. From DMA analysis, the storage modulus (E’) of VA/MMA-B increased sharply from 15,057 Pa (untreated bamboo) to 17,909 Pa (single-treated bamboo), and the glass transition temperature was improved from 180 °C (raw bamboo) to 205 °C (single-treated bamboo).

Mass-suspension polymerization process as an efficient tool to produce polymer/clay nanocomposites

2021 ◽  
Vol 04 ◽  
Author(s):  
Mariaugusta F. Mota ◽  
Thainá Araruna ◽  
Nathália M. Campelo ◽  
Meiry Gláucia F. Rodrigues ◽  
Gabriella R. Ferreira ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Suspension Polymerization ◽  
Experimental Studies ◽  
Ethyl Acrylate ◽  
Polymerization Process ◽  
Basal Spacing ◽  
Polymeric Nanocomposites ◽  
Poly Methyl Methacrylate ◽  
Modified Clays

Background: This work presents the preparation and characterization of the polymeric nanocomposites based on methyl methacrylate (MMA), ethyl acrylate (EA), and natural and modified clays. The clays used to prepare the composite were natural green bentonite (GBC-N) and organophilic clays modified with ammonium quaternary salts: Praepagen (GCBP), Dodigen (GCB-D) and Praepagen/Dodigen mixture 1:1 in weight (GCB-P/D). Objective: The experimental studies focused on the evaluation of the effect of clays (in natura and chemically modified) on the final quality of the polymeric nanocomposites containing around 3 wt%. of clay nanocharges in association with MMA to produce poly(methyl methacrylate)/clays; and MMA/EA to form poly(methyl methacrylate-co-ethyl acrylate)/clays. Materials and Methods: The poly(methyl methacrylate)/clay and poly(methyl methacrylate-co-ethyl acrylate)/clay materials were synthesized through mass-suspension polymerization process. The natural and modified green bentonite clays were characterized by X-ray powder diffraction (XRD), infrared spectroscopy (IR), Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) analyzes to understand its effect on the basal spacing, d001 (compared to the pure clay), as a result of cation exchange step, in which also improved the thermal efficiency of the final nanocomposites. Results: The proper incorporation of MMA and MMA/AE monomers between the layers of natural and modified clays occurred through in situ mass-suspension polymerization, leading to a successful exfoliation of clay layers during the growth of the polymer chains. Conclusion: The IR, SEM, TGA and DSC analyzes confirmed the improvement in the thermal property of the composites compared to polymers formed in the absence of clays. The experimental results are very promising, indicating that the experimental protocol based on the in situ formation of polymer nanocomposites by the using sequential mass-suspension polymerization consist of an interesting tool.

Preparation of poly(methyl methacrylate) and polystyrene-composite-filled porous epoxy microparticles via in-situ suspension polymerization

2011 ◽  
Vol 30 (8) ◽  
pp. 841-847 ◽  
Author(s):  
Du Ngoc Uy Lan ◽  
Shingo Hadano ◽  
A. Abu Bakar ◽  
B. Azahari ◽  
Z.M. Ariff ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Suspension Polymerization ◽  
Poly Methyl Methacrylate

scholarly journals Ferrocenylmethylphosphanes and the Alpha Process for Methoxycarbonylation: The Original Story

Inorganics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 57
Author(s):  
Kevin M. Fortune ◽  
Christa Castel ◽  
Craig M. Robertson ◽  
Peter N. Horton ◽  
Mark E. Light ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Crystal Structures ◽  
Palladium Complexes ◽  
Two Stage ◽  
Stage Process ◽  
Ligand Precursors ◽  
Original Story ◽  
Methyl Propanoate

The Lucite Alpha process is the predominant technology for the preparation of acrylics. This two-stage process involves the palladium-catalysed formation of methyl propanoate from ethene, CO, and methanol, followed by the oxidative formylation of methyl propanoate into methyl methacrylate. A range of bis-1,2-disubstituted aminomethylferrocenes has been prepared and characterised. These complexes serve as precursors to a variety of bulky ferrocenylmethyldiphosphanes that, in turn, function as ligands in the palladium-catalysed process. We describe the crystal structures of five ligand precursors and provide a rationale for their design. In situ catalyst testing on palladium complexes derived from ferrocenylphosphanes demonstrates that these are highly selective (>99.5%) catalysts for the formation of methyl propanoate from ethene, CO, and methanol and have turnover numbers exceeding 50,000. This article credits those researchers who worked on this project in the early days, who received little or no credit for their achievements and endeavours.

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