The effect of initiator encapsulation on methyl methacrylate polymerization by isothermal differential scanning calorimetry

2020 ◽  
Vol 37 (3) ◽  
pp. 183-192
Author(s):  
Seok Min Lee ◽  
Mi Rae Kim ◽  
Hee Jung Park ◽  
Kang Ho Cheon ◽  
Kee Yoon Lee
e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Christian Goretzki ◽  
Helmut Ritter

AbstractThe synthesis and free radical polymerization of a methacrylamide monomer, 5, bearing non-covalently attached cyclodextrins and the chalcone function with a barrier group, is described. The first step of preparation of the monomer was the condensation of 4-(N-methacryloyl-6-aminohexanoylamino)- acetophenone, 1, with 4-nitrobenzaldehyde. The resulting 1-(N-methacryloyl-6- aminohexanoyl-4-aminophenyl)-3-(4-nitrophenyl)-2-propen-1-one, 2, was reduced with tin(II) chloride dihydrate to the corresponding 1-(N-methacryloyl-6-aminohexanoyl- 4-aminophenyl)-3-(4-aminophenyl)-2-propen-1-one, 3. After this, the aminochalcone was condensed with a barrier group, triphenylacetyl chloride, yielding 1-(N-methacryloyl-6-aminohexanoyl-4-aminophenyl)-3-(N’-triphenylacetyl- 4-aminophenyl)-2-propen-1-one, 4. Monomer 4 was copolymerized with methyl methacrylate to the model polymer poly[4-co-methyl methacrylate], 6, and also complexed with dimethylated β-cyclodextrin to the semi-rotaxane (4 / 2,6-Me2-β- CD) 5, which was copolymerized with methyl methacrylate, yielding a polyrotaxane (5-co-methyl methacrylate) 7, containing a cyclodextrin ring in the side-chain. The semi-rotaxane 5 and both copolymers 6 and 7 were characterized spectroscopically and also by means of differential scanning calorimetry, gel permeation chromatography and thermogravimetrical analysis, and - in the case of 5 - by mass spectrometry. Furthermore, the UV-induced E/Z-isomerization of both polymers 6 and 7 was examined in tetrahydrofuran solution. A retarding effect of the noncovalently attached cyclodextrin was finally detected.


1970 ◽  
Vol 33 (1) ◽  
pp. 15-24 ◽  
Author(s):  
MF Mina ◽  
GH Michler ◽  
FJ Balta Calleja

Glass transition temperature (Tg) of core-shell particles-toughened poly(methyl- methacrylate) (CSPTPMMA) and natural rubber-toughened PMMA (NRTPMMA), which are basically the PMMA/elastomer blends with different concentrations of elastomer heterogeneously distributed in the samples, was investigated by means of differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) and microindentation technique (MT). Microhardness (H) of the samples was measured using MT. Core-shell particles (CSP) with a rubbery shell and natural rubber (NR) were used as reinforcing materials for the production of compatible and incompatible blends, respectively. Results reveal a good correlation of the glass transition temperature (Tg) obtained from DSC and DMA, and that deduced from MT.  The H-value of each sample is compared with its Tg-value. Increase of Tg with the increase of H, which is a general behavior of polymers, is not maintained in the both blends investigated. Contrary to expectation, H is shown to decrease with increasing glass transition temperature in case of CSP-toughened compatible blends while it decreases with the decrease of Tg-value only in case of NR-modified incompatible blends for lower NR concentration (<1 wt%) and does not depend on Tg for rubber content higher than 1 wt%.  Keywords: Glass transition temperature, microhardness, rubber-toughened poly(methyl -methacrylate), core-shell particle, differential scanning calorimetry DOI: 10.3329/jbas.v33i1.2946 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 1, 15-24, 2009


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