Synthesis and characterization of organically modified clay/castor oil based chain extended polyurethane nanocomposites

Synthesis and characterization of polyurethane–organoclay nanocomposites based on renewable castor oil polyols

“…Some bands in the region located at 2,930, 2,856 and 1,472 cm -1 are attributed to the -CH 2 stretching frequencies, the presence of methylene group. FTIR spectra of pure COPUs and (COPUs-C30B) nanocomposites show a small broad band in the range 4,000-3,500 cm -1 which is associated with O-H stretching vibrations hydroxyl ended compounds [29]. Characteristic peaks of hydrogen bonded -NH groups of urethane linkages were observed at 3,325-3,390 cm -1 and a small band, seen at 3,420 cm -1 is characteristic of stretching of unbound -NH groups.…”

“…3), presence of small bands at 1,560-1,680 cm -1 was observed, which is related to the stretching vibrations of hydrogen bonded organoclay were seen in the spectrum of COPUs-C30B nanocomposites, signifying that the polymer chains have intercalated into the galleries of organoclay and formulation of hydrogen bonding more than COPUs due to the COPUs molecules can be grafted onto the organically modified clay surface through the reaction between the -NCO groups and the -OH groups on the organically modified clay. The tethered organoclay may interfere with the H-bond formation in COPUs composites [25,29].…”

“…Number of research works has been reported related to the castor oil-based polyurethane-organoclay nanocomposites, depending upon type and ratios of diisocyanates, chain extenders and weight percentages of organoclay [28]. Kaushik et al [29] studied a series of 1,4-butane diol chain extended polyurethane nanocomposites based on castor oil, 4,4-diphenylmethane diisocyanate (MDI) with modified clay (Cloisite 30B) as a filler. These nanocomposites exhibited lower water absorption and diffusivity values as compared to neat polyurethane and thermal stability improved with increased percentage of organoclay.…”

Pure Polyurethane and Castor Oil Based Polyurethane: Synthesis and Characterization

“…Comparative FTIR spectra for PU (pure PPG & PPG and castor oil) the larger organic chains present in castor-oil-based PU. Peaks at 1727 cm -1 represent (C=O) non-bonded urethanes [13], which are likely to be present in larger numbers, in the castor-oil-based PU synthesis.…”

“…The study of the preparation from castor oil exhibited increasing diisocyanate groups in relation to the polyol amount and increased the strength at rupture of the obtained polymers and decreased polymer elongation, resulting in an increasing modulus [12]. A series of 1,4-butane diol chain extended PU nanocomposites based on castor oil, and 4,40-diphenylmethane diisocyanate (MDI) were synthesized with modified clay (Cloisite 30B) as the filler [13]. In this study pure PU and PUs based on castor oil were synthesized.…”