Physical properties of silk fibers grafted with a binary mixture of styrene and n‐butyl methacrylate

Abstract

SYNOPSISThe mechanical and physical properties, as well as the crystalline structure of silk fibers grafted with a binary mixture of styrene (St) and n-butyl methacrylate (BMA) were studied as a function of the weight gain. The size of the fibers increased linearly with the extent of grafting. The strength, the elongation at break, and the tensile modulus decreased with increasing weight gain, but the breaking load remained almost unchanged. The difference among the tensile properties measured in dry and wet states decreased beyond weight gain of 50% because of the hydrophobic properties of grafted silk fibers. The thermal behavior was determined by differential scanning calorimetry (DSC ) , thermomechanical analysis (TMA) , and thermogravimetric analysis (TGA) measurements. Silk fibers attained a higher thermal stability as the amount of loaded polymer increased. The thermally induced molecular movement of St/BMA-grafted silk fibers was enhanced as judged by shifting the onset and the position of the dynamic loss modulus ( E " ) peak to lower temperature when the weight gain increased. X-ray diffraction curves demonstrated that the crystalline structure of silk fibers remained unchanged regardless of the St/BMA grafting. 0 1993 John Wiley & Sons, Inc.

Activation of the phosphoinositide‐3‐kinase and mammalian target of rapamycin signaling pathways are associated with shortened survival in patients with malignant peritoneal mesothelioma

“…The reaction needs a radical initiator as hydrogen peroxide, persulfates,4 redox systems involving metal salts,5–7 or radiations 8–10. Many works on silk grafting have been developed using various vinyl monomers: styrene,11 acrylamide,2 methacrylamide,3, 4, 10, 12–20 N ( n ‐butoxymethyl)methacrylamide,21, 22 methacrylonitrile,23, 24 vinyltrimethoxysilane25 and several methacrylates: methyl‐,4–8, 20, 24, 26–29 ethyl‐,24 isopropyl‐,10 n ‐butyl‐,30 benzyl‐,31 glycidyl‐,2 2‐hydroxyethyl‐,3, 4, 9, 10, 18, 19, 32 ethoxyethyl‐methacrylate 33. Methacrylamide (MAA), however, is the monomer most used in industry because it gives products with soft hand, crease recovery (up to 30% weighting), and increased hygroscopicity 14, 18…”

Silk grafting with methacrylic monomers: Process optimization and comparison

“…[8][9][10] Many works on silk grafting have been developed using various vinyl monomers: styrene, 11 acrylamide, 2 methacrylamide, 3,4,10,[12][13][14][15][16][17][18][19][20] N(nbutoxymethyl)methacrylamide, 21,22 methacrylonitrile, 23,24 vinyltrimethoxysilane 25 and several methacrylates: methyl-, [4][5][6][7][8]20,24,[26][27][28][29] ethyl-, 24 isopropyl-, 10 n-butyl-, 30 benzyl-, 31 glycidyl-, 2 2-hydroxyethyl-, 3,4,9,10,18,19,32 ethoxyethyl-methacrylate. 33 Methacrylamide (MAA), however, is the monomer most used in industry because it gives products with soft hand, crease recovery (up to 30% weighting), and increased hygroscopicity.…”

Chemical modification of silk fibroin with 2-methacryloyloxyethyl phosphorylcholine I. Graft-polymerization onto fabric using ammonium persulfate and interaction between fabric and platelets

“…2) showed absorptions at 970 cm −1 attributed to −N + (CH 3 ) 3 and that at 1240 cm −1 attributed to POCH 2 groups in poly MPC, increased with proceeding graft polymerization. Several monomers—methacrylamide (MAm),8 methyl methacrylate,9 and styrene10—were grafted onto silk fiber and fabric using peroxide as an initiator, and the weight gain with these graft polymers onto silk substrates was ≈ 120 wt %. The maximum weight gain, however, was approximately 10 wt % in our MPC graft polymerization.…”