Young modulus, LDPE

Fig. 8.11 Tensile strength, Young modulus, and elongation at break of a pure LDPE b LDPE/iPP common blend c LDPE/iPP in situ nanofibrillar composite with epitaxy structure d LDPE/iPP in situ nanofibrillar composite with NHSK structure e pure iPP...

The effect of blending LDPE with EVA or a styrene-isoprene block copolymer was investigated (178). The properties (thermal expansion coefficient. Young s modulus, thermal conductivity) of the foamed blends usually lie between the limits of the foamed constituents, although the relationship between property and blend content is not always linear. The reasons must he in the microstructure most polymer pairs are immiscible, but some such as PS/polyphenylene oxide (PPO) are miscible. Eor the immiscible blends, the majority phase tends to be continuous, but the form of the minor phase can vary. Blends of EVA and metallocene catalysed ethylene-octene copolymer have different morphologies depending on the EVA content (5). With 25% EVA, the EVA phase appears as fine spherical inclusions in the LDPE matrix. The results of these experiments on polymer films will apply to foams made from the same polymers. 

Young s modulus for LDPE foams versus relative density, compared with predictions for the Kelvin foam (a.l5)... 

The faces in low density LDPE foams are partly buckled or wrinkled, as a result of processing (a.l7). This affects both the bulk modulus and the Young s modulus. The foam bulk modulus Kp is predicted, using the Kelvin closed cell foam model, to be ... 

Despite many studies of the effects of photooxidation on mechanical properties (such as Young s modulus, tensile strength, ultimate elongation, etc.. ..), there is very little information about these effects on fatigue life. For that reason, we studied the fatigue life of LDPE films as a function of UV exposure. The results are shown in Fig. 2 where logNp (Np being the number of cycles sustained before failure) is plotted vs. time of UV exposure. In this case the strain amplitude is 8% and the frequency (oj) is 10 cycles/mln. 

The stiffness of PHA copolymers can be controlled by the incorporation of mcl-3HA comonomer units (Noda et al. 2005b). Figure 12 shows Young s modulus of various PHA copolymers systematically decreases with the addition of 3HA comonomers. The effect of reduced crystallinity by incorporating more mcl-3HA is apparent. The incorporation of a higher level of mcl-3HA results in lower crystallinity, which in turn makes the material softer. The value of Young s modulus of PHA varied between that of very stiff polymers, such as poly(lactic acid) (PLA) and PP, and much softer material, such as LDPE. 

Figure 22.4 (a) Tensile strength and (b) Young s modulus of LDPE/TPSS blends reinforced by KCE... 

Xiao and co-workers [79] found that the Young s Modulus and tensile strength of carbon nanofibre reinforced LDPE increased by 89 and 56%, respectively, with incorporation of CNT. 

The effects of modifying particulate surfaces are illustrated in terms of the mechanical properties of the filled LDPE. In Fig. 30 are given the values of Young s modulus vs CaC03 concentrations (wt%) for different particulate surface treatments. Addition of unmodified filler raises the modulus (Fig. 30, curve 1) as may be expected. Modifications of the acid-base interaction characteristics and of the surface energies yield major changes in the effect of filler on modulus. Treatments in Ar, CH4 and both Ar and CH4 plasma are most effective in increasing the modulus of the compounds (curves 2 and 3, Fig. 30), while the treat-... 

The temperature at the maximum degradation rate. Young s modulus. Break strength. Elongation at break. Analyses were performed on commercially available LDPE and PS samples. I = modified BFE initiator, typically (NF05-BFE3). A typical elastomer. 

Figure 3.17 Variation of Young s modulus with angle 0 to draw direction for LDPE sheet drawn...

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