Thermally recoverable crosslinked polyethylene

Abstract

ABSTRACT:The thermal recovery of the stored stress in crosslinked polyethylene has been commercially exploited in the preparation of heat shrinkable materials. The study on thermally recoverable crosslinked polyethylene compositions is reported in this paper. Thermally recoverable compositions were prepared by crosslinking of four grades of polyethylenes in air using g-rays from a Co-60 source. The effect of the irradiation dose on the gel fraction and radiation dose to gelation is studied. The effect of the melt index (MI) and the density of the polyethylene on the gel fraction, radiation dose to gelation, and recovery percentage of the stored stress is also studied. It is observed that the gel fraction is higher in case of the lower MI material and that rate of recovery is higher at higher temperatures. The rate of recovery of the stored stress is higher in case of the 100 kGy irradiated sample.

Study of Heat Shrinkability and Flame Retardancy of Poly(ethylene vinyl acetate)/Epichlorohydrin Blends

“…The shrinkage must increase with increase in p-p interaction, which behaves as stored memory in the sample. [8,14] Again Figure 2 shows that with increase in elastomer content the shrinkage increases at a fixed cure time (20 min). Recoiling is controlled by comparatively highly oriented amorphous materials as well as memory points.…”

“…The highest flame retardancy is obtained in presence of Sb 2 O 3 / Chlorohor and TPP/Zn metaborate. tant features of poly(ethylene vinyl acetate) for which it has been selected here are its lower response temperature of the shape memory effect, [8] good recovery and good flow behavior (important for heat shrinkable materials) [9] and low heat conductivity. [10] The objective of the present investigation is to develop blends of poly(ethylene vinyl acetate) with epichlorohydrin (EPH) with reference to their heat shrinkability and flame retardancy for commercial applications.…”

Ultra nano-hardness of surface layer of irradiated high–density polyethylene (HDPE)

“…The aim of this paper is to study the effect of ionizing radiation with different doses, on ultra nano-hardness of surface layer of high-density polyethylene (HDPE) and compare these results with those of non-irradiated samples. The study is carried out due to the ever-growing employment of this type of polymer high-density polyethylene (HDPE) [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20].…”

Heat Shrinkable Behavior and Mechanical Response of a Low‐Density Polyethylene/Millable Polyurethane/Organoclay Ternary Nanocomposite

“…Cross-linked thermoplastics (such as low-density polyethylene (LDPE) and ethylene-vinyl acetate copolymer (EVA), etc. ), [1][2][3][4][5][6] elastomer-plastic blends, [7,8] and segmented block copolymers [9,10] have gained considerable attention over the years from a heat shrinkability point of view. Recently polymer/layered silicate nanocomposites have attracted great interest since they frequently exhibit unexpected hybrid properties derived from their organic and inorganic counterparts.…”