Preparation and characterization of graft copolymers of methyl methacrylate and poly(n-hexyl isocyanate) macromonomers

Abstract

Living poly(n-hexyl isocyanate) (PHIC) was deactivated with methacryloyl chloride to produce methacryl-terminated poly(n-hexyl isocyanate) (PHIC-MA) rodlike macromonomers. Radical copolymerization of methyl methacrylate (MMA) with PHIC-MA was performed using 2, 2'-azobis(isobutyronitrile) as an initiator in benzene at 60°C to prepare poly(methyl-2-methacrylate)-graft-poly(n-hexyl isocyanate) (PMMA-graft-PHIC) graft copolymers. The monomer reactivity ratios of MMA (M 1) and PHIC-MA (M 2) were evaluated as r 1 = 11.5 and r 2 = ~ 0, exhibiting remarkably lower reactivity of PHIC-MA macromonomer than that of common macromonomers. The resultant graft copolymers were characterized using gel permeation chromatography equipped with low-angle laser light-scattering to determine the molecular weights, and equipped with a refractive index detector and an ultraviolet light detector to estimate a PHIC weight fraction of PMMA-graft-PHIC at the ith elution volume of the GPC chromatogram. There are 2-3 PHIC grafts per PMMA molecule, and the PHIC rodlike chains might be difficult to introduce into the PMMA main chains having higher molecular weights. A specific dimension of PMMA-graft-PHIC in solution was discussed in detail.

Al2O3/SnO2 Co‐Nanoparticle Modified Grafted Collagen for Improving Thermal Stability and Infrared Emissivity

“…However the weight loss of the grafted collagen-Al 2 O 3 /SnO 2 composites was very fast, which only occurred in the range of 210-420 ℃ with a dramatic decrease from 360 to 400 ℃. Furthermore the weight variations of the grafted collagen-S 24 and S 30 were much larger than that of the grafted collagen-xerogel. The original degradation temperature of collagen was only 39 ℃.…”

“…The infrared emissvity testing data were given in Table 1, where it was observed that the infrared emissivity 24 : 0.708). As known, there were two main modes of heat transfer (infrared energy) through a fibrous insulator: (1) the heat conduction through the gas filling the space between the fibers, and (2) the heat transferred by thermal radiation that was emitted, absorbed, and scattered by the fibers.…”

“…22 Noticeable improvement of the surface properties of the collagen has been obtained by radical copolymerization with some lipophilic materials such as methyl methacrylate (MMA). 23,24 The polymer of MMA (PMMA) obtained by using 2,2'-azobis(isobutyronitrile) as an initiator possesses good biocompatibility and has been used in biomedical field particularly in strengthening of some biopolymer. 23,25 In this paper, we prepared a grafted collagen matrix with a graft copolymerization method and synthesized Al 2 O 3 /SnO 2 co-nanoparticles by a modified sol-gel technique followed by a thermal treatment process.…”

“…The thermal decomposition of the bimetal xerogel was carried out after it was completely dried. The solid residue was heated to 450 in air ℃ at a heating rate of 10 •min ℃ -1 and then annealed at this temperature for 24, 30 and 36 h under an air atmosphere to produce three powdery products marked as S 24 , S 30 and S 36 , respectively.…”

Anionic living polymerization of macromonomers: Preparation of a particle-like purging reagent and characterization of poly(macromonomer)s

“…The M GPC n star values correspond to the dimensions of the star polymers in THF as a result of the mechanism of the GPC measurements. Hence, the M GPC n star = M LALLS n star ratios might correspond to the specific volume ðv star s Þ of the poly(PSM) n star polymers in THF [29]: …”