The effect of electron irradiation on the structure and mechanical properties of highly drawn polyethylene fibers

Klein, P. G.; Woods, Daniel; Ward, I. M.

doi:10.1002/polb.1987.090250701

Cited by 65 publications

(71 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…They found that the creep and recovery behavior of the irradiated fibers was greatly improved and that the acetylene effectively lowered the dose at which these improvements were achieved. The work reported in this paper is concerned with extending the application of gamma irradiation to large diameter (10 mm) HOPE.…”

Section: Introductionmentioning

confidence: 99%

The effect of gamma ray irradiation on the mechanical properties of large cross‐section oriented polyethylene rods

Sangster

Barry

1991

J of Applied Polymer Sci

View full text Add to dashboard Cite

SYNOPSISThe effect of gamma irradiation, in acetylene, on large diameter oriented polyethylene has been investigated. The dependency of gel content, melting point, and crystallinity on dose was evaluated. The gel content dose relationship showed two regions, indicating that an effective network is formed at low doses, 60 kGy. Irradiating the oriented rod in acetylene was found to more than double the initial tensile modulus. This improvement in the tensile properties resulted in improved creep-strain resistance for the material. These improvements in the mechanical properties were attributed to crosslinks formed both in the amorphous regions and a t the surfaces of the crystalline regions. At high doses > 180 kGy degradation of the oriented polymer resulted in a deterioration in mechanical properties.

show abstract

Section: Introductionmentioning

confidence: 99%

The effect of gamma ray irradiation on the mechanical properties of large cross‐section oriented polyethylene rods

Sangster

Barry

1991

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…This is in agreement with our results for unoriented and oriented LLDPE and UHMWPE 4 • 5 and also with decreasing of activation volume observed in creep measurements. 12 crystallinity which are related to melting endotherms of unoriented samples in Figure 8a. Irradiation produces an increase in the heat of fusion and consequently in crystallinity due to scission of tie molecules.…”

Section: Resultsmentioning

confidence: 99%

“…31, No. 12,1999 high coefficient of viscosity (17 1 ), is associated to crystal fraction. The second process is characterized by a small viscosity coefficient (17 2 ) and corresponds to the amorphous fraction.…”

Section: Discussionmentioning

confidence: 99%

Stress Relaxation in High Density Polyethylene. Effects of Orientation and Gamma Radiation

Djoković¹,

Kostoski²,

Dramićanin³

et al. 1999

Polym J

View full text Add to dashboard Cite

ABSTRACT:The stress relaxation of unoriented (A= I) and oriented().= 9) high density polyethylene (HDPE) was studied for different levels of radiation (0, 100, 300, and 500 kGy). The relaxation behavior is analyzed in terms of a formerly established two-process model. In that model, one process is related to the crystal and the other to the amorphous fraction of a polyethylene sample. The modified viscoelastic properties of HDPE, due to effects of orientation and irradiation, are reflected in changes in viscosity coefficients and elasticity moduli of these two fractions. This made possible better comprehension of the nature of changes in the relaxation behavior of HDPE induced by irradiation and orientation.KEY WORDS Stress Relaxation I Crystal Fraction I Amorphous Fraction I Polyethylene IThe effects of ionizing radiation and orientation on the mechanical relaxation of polyethylene have been the subject of recent publications. 1 -6 Some of these studies have shown an increase in intensity of the stress relaxation with orientation. 1 -3 This behavior is a consequence of the reduced mobility of highly stretched tie molecules in oriented samples. It has also been shown that radiation crosslinking can improve stability to applied stress up to 30%. 2 -6 Formation of network suppresses the cold flow and increases internal resistance of the sample.For better understanding of the influence of irradiation and orientation on the relaxation behavior, in our previous paper 4 we proposed a two-process model for the stress relaxation in linear low density polyethylene (LLDPE). The model is based on the assumption that the stress relaxation can be represented with two thermally activated processes acting in parallel, each related with one fraction of polyethylene sample: crystal or amorphous. The process which takes place in a crystal domain is, in fact, a propagation of defects through the lattice, as it has been established earlier by Wilding and Ward. 7 This approach is explored further in the present paper by examining the effects of orientation and different adsorbed doses of radiation on the relaxation behavior of high density polyethylene (HDPE). Since the relaxation process is very sensitive to prior structure of the samples, we used differential scanning calorimetry (DSC) and gel measurements to find out the changes in the crystal fraction and the degree of network formation respectively. EXPERIMENTALIn these investigations HDPE HIPLEX EHM 6003 p=0.96gcm-3 and Mw=76700 was used. Preparation and irradiation of the samples are described in previous studies. 3 -5 There are two types of samples, unoriented (A= 1) and oriented (A=9), which were exposed to 6°C o gamma-source up to absorbed doses of 0, 100, 300, and 500 kGy. Initial elasticity moduli of unirradiated samples were E=0.6GPa for A= 1 and E=2.9GPa for A= 9. These values were obtained from stress-strain 1194 measurements using Zwick tensile testing machine at a load rate of 20 em min-1 .The stress relaxation measurements are also performed on a Zwick tensile...

show abstract

“…Chemical crosslinking is performed before drawing [17] at intermediate state of drawing [18][19][20][21][22][23] or after drawing. [24][25][26][27][28][29][30][31][32][33][34][35][36] Extensive chemical crosslinking before or during drawing inevitably limits the maximum attainable draw ratio and reduces the maximum attainable Young's modulus and tensile strength. [17][18][19] On the other hand, a low degree of crosslinking before or during drawing results in minor improvements of the creep resistance.…”

Section: Introductionmentioning

confidence: 99%

A novel, efficient route for the crosslinking and creep improvement of high modulus and high strength polyethylene fibres

Jacobs

Heijnen

Bastiaansen³

et al. 2000

Macromol. Mater. Eng.

View full text Add to dashboard Cite

The effect of electron irradiation on the structure and mechanical properties of highly drawn polyethylene fibers

Cited by 65 publications

References 20 publications

The effect of gamma ray irradiation on the mechanical properties of large cross‐section oriented polyethylene rods

The effect of gamma ray irradiation on the mechanical properties of large cross‐section oriented polyethylene rods

Stress Relaxation in High Density Polyethylene. Effects of Orientation and Gamma Radiation

A novel, efficient route for the crosslinking and creep improvement of high modulus and high strength polyethylene fibres

Contact Info

Product

Resources

About