Effect of crosslinking agents on the structure and properties of polyurethane millable elastomer composites

Abstract

SYNOPSISA study of the effect of crosslinking agents on the structure and properties of the millable polyurethane ( P U ) elastomer is reported here. Effects of the conventionally used dicumyl peroxide (DCP) and tolylene diisocyanate dimer (TDID) on the curing characteristics, mechanical properties, and relative thermal stabilities of the P U composites have been compared. Use of X-ray diffraction as a supportive evidence helps in understanding the nature of crosslinking. The mixture of DCP and TDID is also evaluated as crosslinking agents. A dramatic improvement in the mechanical properties and thermal stability is observed because of the mixed type of crosslinking obtained by the combined use of DCP and TDID. Effect of carbon black loading shows an increase in the mechanical strength with a decrease in the elongation. The results obtained from various properties measurements have been satisfactorily explained with a general model of crosslinking.

Influence of varying hard segments on the properties of chemically crosslinked moisture‐cured polyurethane‐urea

“…The chemical crosslinks have been introduced into the samples in a variety of ways, and studies have been attempted to examine the effects of chemical crosslinking on the material properties of polyurethane elastomers. Some systems contain triols or higher‐functional polyols,8–13 isocyanates with functionalities greater than two,5, 14 NCO/OH ratios greater than one,2, 11–13, 15, 16 or combinations thereof 2, 11–13. Many of these studies have focused on the tensile and mechanical properties of the polymers 2, 5, 8–17.…”

“…Some systems contain triols or higher‐functional polyols,8–13 isocyanates with functionalities greater than two,5, 14 NCO/OH ratios greater than one,2, 11–13, 15, 16 or combinations thereof 2, 11–13. Many of these studies have focused on the tensile and mechanical properties of the polymers 2, 5, 8–17. In addition, the effects of crosslinking on swelling,2, 5, 8, 12–15, 17 thermal degradation,10, 14, 16 thermal properties,2, 5, 14, 17 and morphology13, 14, 16 have been examined.…”

Effects of crosslinking on thermal and mechanical properties of polyurethanes

“…Many of these studies have focused on the tensile properties of the polymers. [2][3][4][5][6][7][8][9][10][11][12][13] In addition, the effects of crosslinking on swelling, 2,3,5,8,9,[11][12][13] thermal degradation, 6,10,12 thermal properties, 5,9 -12 and morphology 10,12,13 have been examined. The chemical crosslinks have been introduced into the samples in a variety of ways.…”

Preparation and characterization of carbonyl iron powder/millable polyurethane elastomer microwave absorbing patch

“…Polyurethane elastomer (PU) is a polymer with a strong polarity that can be pasted to the inner surface of devices easily and firmly. Moreover, PU has many excellent physical, chemical, and mechanical properties, such as softness, high strength, antioxidation, low‐temperature stability, radiation resistance, and abrasion resistance . Millable PU (MPU) is similar in appearance to general‐purpose rubber, which suggests that the materials serve similar functions.…”