We report on the preparation, characterization, and foaming behavior of cellular polymers based on 1-vinyl-2-pyrrolidone (VP) and methyl methacrylate (MMA). Samples with different feed ratios proportions of VP and MMA were prepared following the bulk radical copolymerization procedure, using commercially available monomers and testing two different initiators (photochemical and thermal), obtaining solid samples of around 1.5 mm thick. To evaluate the polymerization process, the chemical structure of VP/MMA copolymers was determined by proton nuclear magnetic resonance measurements. In a second step, single-batch supercritical carbon dioxide (CO2) foaming tests were carried out at different temperatures to evaluate the influence of the VP to MMA feed ratios and the foaming temperature in the density, the presence of solid outer skin, the CO2 sorption–desorption process, and the cellular morphology of the foamed polymers.
LiuSDuvigneauJGVancsoJ. Nanocellular polymer foams as promising high performance thermal insulation materials. Eur Polym J2015; 65: 33–45.
2.
BordatABoissenotTNicolasJ, et al.Thermoresponsive polymer nanocarriers for biomedical applications. Adv Drug Deliv Rev2019; 138: 167–192.
3.
MalinconicoMCerrutiPSantagataG, et al.Natural polymers and additives in commodity and specialty applications: a challenge for the chemistry of future. Macromol Symp2014; 337: 124–133.
4.
ZhuYRomainCWilliamsCK. Sustainable polymers from renewable resources. Nature2016; 540: 354–362.
5.
SanJuánAMReglero RuizJAGarcíaFC, et al.Recent developments in sensing devices based on polymeric systems. React Funct Polym2018; 133: 103–125.
6.
ZamaniaFGMoulahoumaHOdaciM, et al.The modern role of smartphones in analytical chemistry. Trends Anal Chem2019; 118: 264–276.
7.
VallejosSMuñozAIbeasS, et al.Solid sensory polymer substrates for the quantification of iron in blood, wine and water by a scalable RGB technique. J Mater Chem A2013; 1: 15435–15441.
8.
Trigo-LópezMMuñozAIbeasS, et al.Colorimetric detection and determination of Fe (III), Co (II), Cu (II) and Sn (II) in aqueous media by acrylic polymers with pendant terpyridine motifs. Sensor Actuat B Chem2016; 226: 118–126.
9.
NotarioBPintoJRodríguez-PérezMA. Nanoporous polymeric materials: a new class of materials with enhanced properties. Prog Mater Sci2016; 78-79: 93–139.
10.
Martín de LeónJPuraJLBernardoV, et al.Production and characterization of nanocellular polymers based on nanostructured PMMA blends and PMMA nanocomposites. Polymer2019; 70: 16–23.
11.
PascualBSVallejosSRamosC, et al.Sensory polymeric foams as a tool for improving sensing performance of sensory polymers. Sensors2018; 18: 4378(1)–4378(9).
12.
Reglero RuizJAVallejosSPascualBS, et al.Microcellular polymer films based on cross-linked 1-vinyl-2-pyrrolidone and methyl methacrylate. J Supercrit Fluid2018; 140: 270–278.
13.
NalawadeSPPicchioniFJanssenLPBM, et al.Solubilities of sub- and supercritical carbon dioxide in polyester resins. Polym Eng Sci2006; 46: 643–649.
14.
CurtisTRSchindelinJHinerMC, et al.ImageJ2: ImageJ for the next generation of scientific image data. BMC Bioinf2017; 18: 529(1)–529(26).
15.
PintoJSolórzanoERodríguez-PérezMA, et al.Characterization of the cellular structure based on user-interactive image analysis procedures. J Cell Plast2013; 49: 555–575.
16.
RindfleischFDiNoiaTPMcHughMA. Solubility of polymers and copolymers in supercritical CO2. J Phys Chem1996; 100: 15581–15587.
17.
SatoYFujiwaraKTakikawaT, et al.Solubilities and diffusion coefficients of carbon dioxide and nitrogen in polypropylene, high-density polyethylene, and polystyrene under high pressures and temperatures. Fluid Phase Equilib1999; 162: 261–276.
18.
Ikeda-FukazawaTKitaDNagashimaK. Raman spectroscopic study of CO2 sorption process in poly methyl methacrylate. J Polym Sci B: Polym Phys2008; 46: 831–842.
19.
GuoHKumarV.Solid-state poly (methyl methacrylate) (PMMA) nanofoams. Part I: low-temperature CO2 sorption, diffusion, and the depression in PMMA glass transition. Polymer2015; 57: 157–163.
20.
JinJ-SChangC-WZhuJ, et al.Solubility of poly (vinyl pyrrolidone) with different molecular weights in supercritical carbon dioxide. J Chem Eng Data2015; 60: 3397−3403.
21.
Reglero RuizJATallonJ-MPedrosM, et al.Two-step micro cellular foaming of amorphous polymers in supercritical CO2. J. Supercrit Fluid2011; 57: 87–94.
22.
Trigo-LópezMVallejosSReglero RuizJA, et al.Fabrication of microporous PMMA using ionic liquids: an improved route to classical ScCO2 foaming process. Polymer2019; 183: 121867(1)–121867(9).
23.
RadhakrishnaGRupeshDAbhishekG. Bimodal microcellular morphology evaluation in abs-foamed composites developed using step-wise depressurization foaming process. Polym Eng Sci2020; 60: 113–131.
