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To improve the chemical, physical, mechanical and thermal properties of polyvinyl acetate (PVAc), N-hydroxymethyl acrylamide (NMA) was used to polymerize with vinyl acetate (VAc). During the emulsion polymerization of VAc using polyvinyl alcohol as protective colloid and ammonium persulfate as initiator, PVAc-NMA was prepared under the conventional...
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... test the chemical structure of PVAc and PVAc-NMA, first the obtained polymers were purified. After being washed in 30 C warm water and filtering for about 5 times, they were tested by the NICOLET 380 Fourier transform infrared spectro- scopy (FTIR; Figure 1). The comparison among FTIR spectra of NMA, PVAc and PVAc-NMA revealed that the absorption peak of PVAc-NMA near 3000 cm became weaker, even disappeared, those near 1600 cm À1 showed a platform from PVAc's originally slightly sharp absorption peak and those near 1100 cm À1 showed two sharp absorption peaks from PVAc's originally wide absorption peaks. ...
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... The polymerization techniques include seeded emulsion polymerization or interpenetrating network (IPN) formation. Hybrid emulsions based on acrylic polymers and polyurethanes are being studied [14][15][16]. These hybrid emulsions are expected to provide the advantages of acrylic polymers, such as hardness, gloss, weathering, and chemical resistance, and the advantages of polyurethanes, such as excellent adhesion and toughness [17,18]. ...
Here, the idea is to synthesize polyvinyl acetate (PVAc)/waterborne polyurethane-based (WPU) hybrid IPN network. The polyvinyl acetate emulsion (PVAc) and vinyl acetate/water-based polyurethane hybrid emulsions were successfully prepared in this research work. The weight percentage of polyurethane components was varied to synthesize emulsions with different properties. Two distinctly designed emulsion’s properties were studied using different characterization techniques such as dynamic light scattering (DLS), gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), nuclei magnetic resonance (NMR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic mechanical and thermal analysis (DMTA) to evaluate emulsion properties. The properties of PVAc and hybrid emulsions were checked, and their relative average molecular weights were determined by GPC. Also, their particle size distribution and zeta potential were performed to analyze the hybrid emulsion’s average volume distribution and stability. Thermomechanical and mechanical properties such as damping factor, storage modulus, loss modulus, tensile strength, and lap shear strength were correlated with the loading of WPU in PVAc emulsion to form a physical crosslinked network. The result showed a minimal change in the thermal response of hybrid emulsion properties but an improvement in lap shear strength was observed in hybrid emulsion compared with PVAc emulsion.Graphical abstract
... These shortcomings have a direct impact on the segment's integrated value of final uses and processing in the wood joinery industry. Numerous studies have been conducted thus far to enhance the performance characteristics of PVAc, including co-polymerization and co-blending [7]- [14]. ...
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... Unsaponified (PVAc/PMMA) (9:1, 7:3, and 5:5) blend films had T g values of 24.1, 25.5, 30.0, and 59.1 • C, respectively, while saponified (PVAc/PMMA) (9:1, 7:3, and 5:5) blend films had T g values of 56.6, 58.0, 58.2, and 59.6 • C, respectively. These results can be explained by the high miscibility between PVAc and PMMA, and PVA and P(MMA-MAA) confirmed by the presence of a single T g peak in the blend films and the results (T g ) are consistent with previous reports [51][52][53]. ...
For the first time, poly(vinyl alcohol) (PVA)/poly(methyl methacrylate–methallyl alcohol) (P(MMA-MAA)) (9:1, 7:3, 5:5) blend films were made simultaneously using the saponification method in a heterogeneous medium from poly(vinyl acetate) (PVAc)/poly(methyl methacrylate) (PMMA) (9:1, 7:3, 5:5) blend films, respectively. The surface morphology and characteristics of the films were investigated using optical microscopy (OM), atomic force microscopy (AFM), X-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Moreover, the effect of the PVAc content on the degree of saponification (DS) of the PVAc/PMMA films were evaluated and revealed that the obtained DS value increased with the increase in PVAc content in the PVAc/PMMA blend films. According to the OM results, the saponified films demonstrated increased surface roughness compared with the unsaponified films. The AFM images revealed morphological variation among the saponified PVAc/PMMA blend films with different mass ratios of 9:1, 7:3, and 5:5. According to the DSC and TGA results, all blend film types exhibited higher thermal property after the saponification treatment. The XRD and FTIR results confirmed the conversion of the PVAc/PMMA into PVA/P(MMA-MAA) films. Thus, our present work may give a new idea for making blend film as promising medical material with significant surface properties based on hydrophilic/hydrophobic strategy.
... In a previous study, VAc and N-hydroxymethyl acrylamide (NMA) were used to form secondary emulsions using different synthesis conditions: Increasing the concentration of the reaction mixture and decreasing the polymerization time influenced the chemical structure, rheology, micelle morphology, and mechanical properties significantly (Cui and Du 2013a). The proportion of NMA had been held constant. ...
In this study, N-hydroxymethyl acrylamide (NMA) and vinyl acetate (VAc) were used in order to prepare secondary emulsions; additionally urea was then introduced into the polymerization to form ternary emulsions, adjusting different proportions of the three components. Compared to pure polyvinyl acetate, these two emulsion types presented shorter curing time, improved water resistance, and higher bond strength; this is based on the crosslinking ability introduced by the NMA, enabling such a partial crosslinking already during the polymerization process and during storage. The viscosity, solid content, storage stability, curing and drying behavior, water resistance, delamination time, and bond strength were influenced by the proportions of NMA and urea in the two systems. Urea had a positive effect on the wet bond strength, but a negative effect on the dry bond strength. The proportion of NMA and of urea during the polymerization preferably was 1–2 % based on VAc.
... It can polymerize with VAc to form a cross-linkable thermosetting copolymerization emulsion of PVAc-NMA. Under heat or in acidic conditions, PVAc-NMA will further cross-link and cure, which had shown better dispersion and longer storage time [12,13] . ...
... Good dispersion or suspension always suggests long pot life and storage time, which has a high practical value in the application [15,16] . From the visual, PVAc-NMA-MMT-STAB was same to the PVAc-NMA and the PVAc-OMMT prepared from the synthesis precursors A to C [9][10][11][12][13] . They were viscous, milk-white, homogeneous, fine emulsions, and all had no coarse particles, no foreign bodies, and no delamination; PVAc-OMMT-D and PVAc-OMMT-E displayed delamination, separation, and precipitates [9][10][11] . ...
... PVAc-OMMT presented large PVAc particles (size 250-500 nm) and small OMMT particles (size 25-100 nm) [9][10][11] . PVAc-NMA particles were about 250 nm together with the condensed polymer of NMA-NMA (size 50-100 nm) [12,13] . ...
In this study, we introduced N-hydroxymethyl acrylamide and an organic montmorillonite intercalated by an octadecyl trimethyl ammonium bromide surfactant together into the in situ polymerization of polyvinyl acetate to form exfoliated nanocomposites. Wide-angle X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, power-law function equation, Newtonian fluid flow equation, Cross-Williamson model viscous equation, Hooke's law, and Poisson's ratio equation revealed the structures, dispersion, rheology, and static tensile properties. The exfoliated nanocomposites were pseudo-plastic non-Newtonian fluids, presented a good dispersion in water, a great storage stability, and a high static tensile strength at 6.78–8.06 MPa.
... Actually, much work on polymer-based inorganic or organic nano-composites was done in our previous work: the synthesis processes of polyvinyl acetate (PVAc) were optimized [3,4], and different intercalated organic montmorillonite (OMMT) was prepared from montmorillonite (MMT) and long alkane chain quaternary ammonium salts [5], such as octadecyl trimethyl ammonium bromide (STAB), dioctadecyl dimethyl ammonium bromide (DOAB), etc. The PVAc [3,4], PVAc-MMT [6,7], PVAc-MMT-STAB [8,9] and PVAc-MMT-DOAB [10,11] were each synthesized through a single process. ...
... Actually, much work on polymer-based inorganic or organic nano-composites was done in our previous work: the synthesis processes of polyvinyl acetate (PVAc) were optimized [3,4], and different intercalated organic montmorillonite (OMMT) was prepared from montmorillonite (MMT) and long alkane chain quaternary ammonium salts [5], such as octadecyl trimethyl ammonium bromide (STAB), dioctadecyl dimethyl ammonium bromide (DOAB), etc. The PVAc [3,4], PVAc-MMT [6,7], PVAc-MMT-STAB [8,9] and PVAc-MMT-DOAB [10,11] were each synthesized through a single process. The polymerization time of 6 h and the water weight of 250 g in the synthesis were fixed as controls. ...
It is very helpful to guide design production and processing conditions for polymer-based inorganic or organic nano-composites by investigating their rheology. In this study, an intercalated nano-composite of montmorillonite (MMT)-dioctadecyl dimethyl ammonium bromide (DOAB) was added and reacted with vinyl acetate (VAc) to form the exfoliated nano-composite of polyvinyl acetate (PVAc)–MMT–DOAB through five different synthesis processes. The MMT–DOAB was exfoliated into nano-particles of layers or sheets and dispersed randomly in PVAc matrix. The different synthesis processes affected the dispersion and apparent viscosity of PVAc and PVAc–MMT–DOAB. With the polymerization time shortening and the water decreasing, the dispersion got bad and the apparent viscosity increased. PVAc and PVAc–MMT–DOAB were pseudo-plastic non-Newtonian fluids and both possessed the normal stress effect (Weissenberg effect) that is also called the pole-climbing phenomenon. By the help of the apparent viscosity analyzed using the power-law function equation, Newtonian fluid flow equation and Cross-Williamson model viscous equation, the different synthesis processes and MMT–DOAB had a certain effect on the rheology of PVAc and PVAc–MMT–DOAB. With the change of different synthesis processes and the increase of MMT–DOAB content in the synthesis system, the estimated molecular weight of PVAc–MMT–DOAB was also increased accordingly.
... [3][4][5][6][7][8][9][10] In our previous work, a natural nanomineral of montmorillonite (MMT) and organic MMT (OMMT) activated by long alkyl chain quaternary ammonium salts were used to polymerize with VAc and the exfoliated nanocomposite of PVAc-MMT 11,12 and PVAc-OMMT was prepared, [13][14][15][16][17][18][19][20] and an amide derivative of N-hydroxymethyl acrylamide (NMA) from unsaturated carboxylic acid was used to copolymerize with VAc to form the copolymer of PVAc-NMA. 21,22 MMT, OMMT and NMA all improved and enhanced the performances and properties of PVAc at a certain extent, but was not perfect. For example, the static tensile of PVAc-MMT and PVAc-OMMT was high, but their dispersion as well as storage time was poor; PVAc-NMA had good dispersion and long storage time, but its static tensile was unsatisfactory. ...
... These differences showed that PVAc-NMA was indeed produced and also PVAc and NMA-NMA. 21,22 The grafted polymer of PVAc-PVA might also be produced according to El-Aasser et al. work. [25][26][27] In that article, PVA was mainly used as the protective colloid. ...
... [11][12][13][14][15][16][17][18][19][20] In PVAc-NMA, PVAc-NMA particles were also larger, their diameter was about 250 nm, and other smaller particles were the condensed polymer of NMA-NMA, their diameter was about 50-100 nm. 21,22 These differences showed that PVAc-NMA had much more significant exfoliation on MMT, and MMT also greatly affected PVAc-NMA. PVAc-NMA particles were much smaller similar with that of MMT particles, so it was difficult to distinguish them clearly. ...
To further improve and enhance the performances and properties of polyvinyl acetate (PVAc), montmorillonite (MMT) and N-hydroxymethyl acrylamide (NMA) were introduced together to polymerize with vinyl acetate (VAc). The exfoliated nanocomposite of PVAc–NMA–MMT was prepared through different synthesis precursors. Linear macromolecular chains of PVAc–NMA were formed in MMT layers. MMT was exfoliated into layers or sheets of nanoparticles and dispersed randomly in PVAc–NMA matrix. Both PVAc–NMA and MMT had small particles with a diameter of 50–100 nm. They dispersed together randomly. PVAc–NMA–MMT was a pseudo-plastic non-Newtonian fluid and possessed the normal stress effect (or Weissenberg effect from the pole-climbing phenomenon. With the change of different synthesis precursors and the increase of NMA content and MMT content in the synthesis system, the molecular weight of PVAc–NMA–MMT increased. PVAc–NMA–MMT had good dispersion, excellent storage stability and high static tensile at 6.47–6.85 MPa.
... In our previous work, some exfoliated nanocomposites of PVAc-MMT [36,37] and PVAc-OMMT [38][39][40][41][42][43][44][45][46][47][48][49] were studied. There, OMMT was prepared by MMT and dioctadecyl dimethyl ammonium bromide (DOAB) and octadecyl trimethyl ammonium bromide (STAB) respectively. ...
... If the content increases or is more than a certain amount, the exfoliated MMT or exfoliated OMMT will decrease while the aggregated ones will increase. In our synthesis, MMT-STAB was optimized to 2% of VAc [36][37][38][39][40][41][42][43][44][45][46][47][48][49] ; this amount would bring helpful effect on the development of exfoliated nanocomposite. ...
Five different processes were designed based on the polymerization time and water amount to investigate their influence on the properties of exfoliated nanocomposites synthesized by vinyl acetate (VAc) and montmorillonite-octadecyl trimethyl ammonium bromide (MMT-STAB). The violent stirring, low MMT-STAB content, high polymerization temperature, favorable polymerization time and suitable water amount were very important. PVAc-MMT-STAB had high static tensile and good dispersion. PVAc's linear macromolecular chains were formed in MMT-STAB layers that was exfoliated into layers or sheets of nanoparticles and dispersed randomly. They dispersed together to form the structures of “Strawberry,” “Swallow,” “Tactoids,” “Half Core-Shell” and “Similar Core-Shell”.
