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1.
Ultra-high-molecular-weight polyethylene (UHMWPE) – carbon black (CB) blends were prepared by gelation/ crystallization from
PE dilute solutions containing CB particles. The UHMWPE/CB composition chosen were 1/0.15, 1/0.25, 1/0.5, 1/0.75, 1/1, 1/3,
1/5, and 1/9, etc. The cross-linking of PE chains was performed by chemical reaction of dicumyl-peroxide at 160 °C. X-ray diffraction patterns indicate that the crystallinity of PE within the blends decreased drastically through the chemical
reaction at high temperature. The sample preparation method by gelation/crystallization provided the UHMWPE–CB system with
various CB contents up to 90% and the conductivities for the resultant specimens were in the range from 10-9 to 1 Ω-1 cm-1 corresponding to the electric conductivity range of semiconductors. The blends assured thermal stability of electric conductivity
by cross-linking of PE chains, although the mechanical property such as the storage and loss moduli were very sensitive to
temperature. The conductivity of the blends with CB content ≥20% were almost independent of temperature up to 220 °C and the values in the heating and cooling processes were almost the same. On the other hand, for the UHMWPE–CB blends with
13% CB content corresponding to the critical one, temperature dependence of electric resistivity showed positive temperature
coefficient (PTC) effect. The PTC intensities for non-cross-linked and cross-linked materials were lower than that of the
corresponding low-molecular-weight-polyethylene (LMWPE)–CB blend but the maximum peak appeared at 160 °C which is higher than the peak temperature of LMWPE–CB blend.
Received: 10 December 1997 Accepted: 9 April 1998 相似文献
2.
Composite materials based on ultrahigh-molecular-weight polyethylene (UHMWPE)–low- molecular-weight polyethylene (LMWPE)
and carbon black (CB) particles were prepared by a gelation/crystallization process from dilute solution. The method was developed
to obtain composite materials with an improved and reproducible positive temperature coefficient (PTC) effect. Drastic improvement
of the PTC effect was achieved when specimens with a LMWPE/UHMWPE composition of 9/1 containing 13 wt% CB were treated at
170 °C without restraint before measurement. The maximum PTC intensity, defined as the ratio of the maximum resistivity to
the resistivity at room temperature, was about 5 orders of magnitude, which equals that of the LMWPE-CB system prepared by
a kneading method. Interestingly, electrical resistivity during the heating-cooling process showed good reproducibility in
the temperature range 30–190 °C, but has never been reported before even for cross-linked LMWPE-CB compostie. Scanning electron
micrographs revealed that CB particles were dispersed in the LMWPE matrix, but not on the UHMWPE fibrils. It turns out that
the network structure of UHMWPE, with a very low melt index, plays an important role in removing the negative temperature
coefficient effect usually observed for the LMWPE-CB system and in ensuring the quality and the reproducibility of the PTC
effect.
Received: 31 August 1998 Accepted in revised form: 4 January 1999 相似文献
3.
Ultra-high molecular weight polyethylene UHMWPE (M
w=4 · 106,I
s=O g/ 10 min), high density polyethylene of normal molecular weight NMWPE (I
s= 4.8 g/10 min) and their blends have been investigated by means of thermomechanical loading in constant and impulse regime. It has been established that after melting, NMWPE passes to a viscous-liquid state. After melting at 138 °C UHMWPE passes to a high-elastic state. The transition of UHMWPE to a viscous-liquid state takes place at temperatures higher than 180 °C and is accompanied by a high-elastic reversible deformation. The blends of UHMWPE with 10 and 20 mass % of NMWPE show a plateau on the thermomechanical curves, corresponding to a high-elastic state, in a shorter temperature range where the deformation is greater. The blends containing the higher percent of NMWPE show thermomechanical curves lacking such a plateau. All blends are characterized by a singular thermomechanically defined temperature of melting, which increases with increase of UHMWPE content. The existence of the high-elastic state in the curves of UHMWPE and its blends containing NMWPE less than 30 mass % above their melting temperatures is explained by the high degree of physical crosslinking of UHMWPE. 相似文献
4.
Morphology and mechanical properties of poly(vinyl alcohol) and starch blends prepared by gelation/crystallization from solutions 总被引:1,自引:0,他引:1
In an attempt to produce biodegradation materials, poly(vinyl alcohol) (PVA)–starch (ST) blends were prepared by gelation/crystallization
from semidilute solutions in dimethyl sulfoxide (Me2SO) and water mixtures and elongated up to 8 times. The content of mixed solvent represented as Me2SO/H2O (volume percent) was set to be 60/40 assuring the greatest drawability of PVA homopolymer films. The PVA/ST compositions
chosen were 1/1, 1/3, and 1/5. The elongation up to 8 times could be done for the 1/1 blend but any elongation was impossible
for blends whose ST content was beyond 50%. When the blends were immersed in water at 20 or 83 °C, the solubility became considerable
for an undrawn blend with 1/5 composition and a drawn 1/1 blend with λ=8. To avoid this phenomenon, cross-linking of PVA chains
was carried out by formalization under formaldehyde vapor. Significant improvement could be established by the cross-linking
of PVA chains. For the 1/1 blend, the amount of ST dissolved in water at 23 °C was less than 3% for the undrawn state and
25% for the drawn film. The decrease in the ST content was enough for use as biodegradation materials. Namely, the water content
relating to the biodegradation in soil is obviously different from such a serious experimental condition that a piece of blend
film was immersed in a water bath. At temperatures above 0 °C, the storage modulus of the formalization blends became slightly
higher than those of the nonformalization blends. The Young's modulus of the drawn films with a draw ratio of 8 times was
2 GPa at 20 °C.
Received: 23 June 2000 Accepted: 30 October 2000 相似文献
5.
L. Vincent S. N. Connolly F. Dolan P. H. Willcocks S. A. A. Jayaweera 《Journal of Thermal Analysis and Calorimetry》2006,86(1):155-164
The fracture toughness of blends
of polypropylene terephthalate (PPT) with polyethylene terephthalate (PET)
and polybutylene terephthalate (PBT) were investigated. Binary blends were
prepared comprising 10:90, 30:70, 50:50, 70:30 and 90:10 mass/mass%. The fracture
toughness was determined for each blend using the essential work of fracture
(EWF) method and thin film double edge notched tension (DENT) specimens. The
specific essential work of fracture, w
e,
values obtained for blends of PET/PPT ranged from 27.33 to 37.38 kJ m–2
whilst PBT/PPT blends yielded values ranging from 41.78 to 64.23 kJ m–2.
Differential scanning calorimetry (DSC) was employed to assess whether or
not crystallinity levels influence the mechanical properties evaluated. The
fracture toughness of PPT deteriorated with PET incorporation. However, high
we values exceeding that of pure PPT were obtained for PBT/PPT blends across
the composition range studied. 相似文献
6.
Setsuko Isaji Yuezhen Bin Masaru Matsuo 《Journal of Polymer Science.Polymer Physics》2009,47(13):1253-1266
Conductive polymer composites (CPC) containing nickel‐coated carbon fiber (NiCF) as filler were prepared using ultra‐high molecular weight polyethylene (UHMWPE) or its mixture with ethylene‐methyl methacrylate (EMMA) as matrix by gelation/crystallization from dilute solution. The electrical conductivity, its temperature dependence, and self‐heating properties of the CPC films were investigated as a function of NiCF content and composition of matrix in details. This article reported the first successful result for getting a good positive temperature coefficient (PTC) effect with 9–10 orders of magnitude of PTC intensity for UHMWPE filled with NiCF fillers where the pure UHMWPE was used as matrix. At the same time, it was found that the drastic increase of resistivity occurred in temperature range of 120–200 °C, especially in the range of 180–200 °C, for the specimens with matrix ratio of UHMWPE and EMMA (UHMWPE/EMMA) of 1/0 and 1/1 (NiCF = 10 vol %). The SEM observation revealed to the difference between the surfaces of NiCF heated at 180 and 200 °C. Researches on the self‐heating properties of the composites indicated a very high heat transfer for this kind of CPCs. For the 1/1 composite film with 10 vol % NiCF, surface temperature (Ts) reached 125 °C within 40 s under direct electric field where the supplied voltage was only 2 V corresponding to the supplied power as 0.9 W. When the supplied voltage was enough high to make Ts beyond the melting point of UHMWPE component, the Ts and its stability of CPC films were greatly influenced by the PTC effect. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 1253–1266, 2009 相似文献
7.
Li-Ting Lee Eamor M. Woo Wei-Ting Chen Ling Chang Kai-Cheng Yen 《Colloid and polymer science》2010,288(4):439-448
Miscibility with a linear T
g–composition relationship was proven for blend of poly(butylene adipate-co-butylene terephthalate) [P(BA-co-BT)] with poly(4-vinyl
phenol) (PVPh). In comparison to the blends of PBA/PVPh and poly(butylene terephthalate) (PBT)/PVPh, the Kwei’s T
g model fitting on data for the P(BA-co-BT)/PVPh blend yields a q value between those for the PBA/PVPh and PBT/PVPh blends. The q values suggest that the interaction strength in the P(BA-co-BT)/PVPh blend is not as strong as that in the PBT/PVPh blend.
Upon mixing the PVPh into the immiscible blend of PBA and PBT, the ternary PBA/PBT/PVPh blends only exhibits partial miscibility.
Full-scale ternary miscibility in whole compositions is not possible owing to the significant ∆χ effect (χ
ij
– χ
ik
). The wavenumber shifts of the hydroxyl IR absorbance band indicates that the H-bonding strength is in decreasing order—PBT/PVPh
> P(BA-co-BT)/PVPh > PBA/PVPh—and shows that the BA segment in the copolymer tends to defray interactions between P(BA-co-BT)
and PVPh in blends. 相似文献
8.
Ya-Ting Hsieh Nai-Tzu Kuo Eamor M. Woo 《Journal of Thermal Analysis and Calorimetry》2012,107(2):745-756
Abstract
Thermal behavior, miscibility, and crystalline morphology in blends of low-molecular-weight poly(l-lactic acid) (LMw-PLLA) or high-molecular-weight PLLA (HMw-PLLA) with various polyesters such as poly(butylene adipate) (PBA), poly(ethylene adipate) (PEA), poly(trimethylene adipate) (PTA), or poly(ethylene succinate) (PESu), respectively, were explored using differential scanning calorimeter (DSC), and polarized-light optical microscopy (POM). Phase behavior in blends of PLLA with other polyesters has been intriguing and not straight forward. Using a low- and high molecular weight PLLA, this study aimed at mainly using thermal analyses for probing the phase behavior, phase diagrams, and temperature dependence of blends systems composed of PLLA of two different molecular weights (low and high) with a series of aliphatic polyesters of different structures varying in the (CH2/CO) ratio in main chains. The blends of LMw-PLLA/PEA and LMw-PLLA/PTA show miscibility in melt and amorphous glassy states. Meanwhile, the LMw-PLLA/PESu blend is immiscible with an asymmetry-shaped upper critical solution temperature (UCST) at 220–240 °C depending on the blend composition. In contrast to miscibility in LMw-PLLA/PTA and LMw-PLLA/PEA blends, HMw-PLLA with polyesters are mostly immiscible; and HMw-PLLA/PTA blend is the only one showing an asymmetry-shaped UCST phase diagram with clarity points at 195–235 °C (depending on composition). Reversibility of UCST behavior, with no chemical transreactions, in these blends was proven by solvent recasting, gel permeation chromatography, and Fourier transform infrared spectroscopy (FT-IR). Crystalline morphology behavior of the LMw-PLLA/PEA and LMw-PLLA/PTA blends furnishes addition evidence for miscibility in the amorphous phase between LMw-PLLA and PTA or PEA. 相似文献9.
Phase behavior and crystal morphology in poly(ethylene succinate) biodegradably modified with tannin
Siti Nurkhamidah Eamor M. Woo I-Han Huang Chean C. Su 《Colloid and polymer science》2011,289(14):1563-1578
Specific interactions, growth kinetics, and dendritic morphology in poly(ethylene succinate) (PESu) biodegradably modified
with various contents of tannic acid (TA) were characterized using differential scanning analysis, Fourier-transform infrared
(FTIR) spectroscopy, polarized-light optical microscopy, and atomic force microscopy. Strong interactions and highly retarded
growth between PESu and a macromolecular ester with polyphenol groups, TA, interaction-induced highly retarded growth rates
for the PESu/TA (80:20) composition are proven to lead to single-crystal-like dendrites when crystallized at high crystallization
temperature (T
c). At T
c = 70 °C, the growth rate for neat PESu is 12 μm/min while it is dramatically depressed to one tenth-fold at 1.5 μm/min with
20 wt.% TA in the blend. Strong specific interactions between the carbonyl group of polyesters and the phenolic hydroxyl group
of TA are confirmed by (1) the blend’s glass transition temperature (T
g)–composition relationship exhibits a sigmoidal curve, well fitted by the Kwei T
g model for miscible blends with large negative q = −90; (2) thermal analysis on crystal melting revealed an interaction parameter χ = −0.64 between PESu and TA; and (3) IR peak shifting analyzed using two-dimensional FTIR technique. A comparative blend
of another polyester poly(hexamethylene sebacate) with TA, lacking the specific interactions, does not exhibit such single
crystals upon similar melt crystallization. 相似文献
10.
J. Pablo Tomba Daniel Portinha Walter F. Schroeder Mitchell A. Winnik Willie Lau 《Colloid and polymer science》2009,287(3):367-378
This paper describes experiments that investigate the use of low glass transition temperature (T
g) latex particles consisting of oligomer to promote polymer diffusion in films formed from high molar mass polymer latex.
The chemical composition of both polymers was similar. Fluorescence resonance energy transfer (FRET) was used to follow the
rate of polymer diffusion for samples in which the high molar mass polymer was labeled with appropriate donor and acceptor
dyes. In these latex blends, the presence of the oligomer (with M
n = 24,000 g/mol, M
w/M
n = 2) was so effective at promoting the interdiffusion of the higher molar mass poly(butyl acrylate-co-methyl methacrylate; PBA/MMA = 1:1 by weight) polymer (with M
n = 43,00 g/mol, M
w/M
n = 3) that a significant amount of interdiffusion occurred during film drying. Additional polymer diffusion occurred during
film aging and annealing, and this effect could be described quantitatively in terms of free-volume theory.
This paper is dedicated to Professor Haruma Kawaguchi to honor his many contributions to the field of latex particles and
their applications. 相似文献
11.
This article describes the structure and electrical performance of positive‐temperature‐coefficient/negative‐temperature‐coefficient (PTC/NTC) effects of the following three‐component blends: poly(4‐methyl pentene‐1)/ultra‐high molecular weight polyethylene/carbon black (TPX/UHMWPE/CB), poly(4‐methyl pentene‐1)/crosslinked‐ultra‐high molecular weight polyethylene/carbon black (TPX/XL‐UHMWPE/CB), and γ‐irradiated, compression‐molded plaques of these blends. CB particles are preferentially attracted to the UHMWPE and XL‐UHMWPE particles, which constitute the dispersed phase within the TPX matrix, but practically cannot or can only very slightly penetrate them because of their extremely high viscosity. Thus, CB particles initially form conductive networks on the UHMWPE phase; this is followed by distribution in the TPX matrix, electrically connecting the CB‐covered UHMWPE particles. This unusual CB distribution results in a reduced percolation threshold of all blends. A double‐PTC effect is exhibited by the XL‐UHMWPE‐containing samples. Irradiation of compression‐molded plaques improves their thermoelectric behavior by amplifying the PTC effect and reducing the NTC effect. A schematic model of the double‐PTC effect is suggested, describing the morphological changes of 70TPX/30XL‐UHMWPE/CB blends at different stages of heating with respect to their thermoelectric behavior. Irradiation of TPX/UHMWPE/CB plaques converts these systems into high‐intensity PTC materials free of the NTC effect. © 2001 John Wiley & Sons, Inc. J Polym Sci B Part B: Polym Phys 39: 1415–1428, 2001 相似文献
12.
This paper deals with the morphology and mechanical properties of blend films for polytetrafluoroethylene (PTFE) and ultra-high molecular weight polyethylene (UHMWPE) prepared by kneading techniques. This experiment was carried out for blend films, prepared with different compositions of PTFE and UHMWPE to improve thermal properties of PE. In spite of the incompatibility of the two polymers, the blend film with the PTFE/UHMWPE composition =75/25 was maintained under the measurement of complex modulus at temperature higher than 300°C. This indicates that the UHMWPE chains dispersed in PTFE fibrous texture were not separated by the melting flow of UHMWPE at 300°C. To check the origin of this interesting phenomenon, the morphology of the blend films was investigated by using scanning electron microscopy, X-ray diffraction, and13C nuclear magnetic resonance. 相似文献
13.
超高分子量聚乙烯(UHMWPE)具有优异的综合性能,本文采用凝胶结晶溶液方法制备了分别以碳纤维(CF)和镀镍碳纤维(NiCF)为导电填料,UHMWPE为基体的3个系列导电聚合物复合材料—UHMWPE/CF、UHMWPE/NiCF和UHMWPE/EMMA/CF复合体系,并分别对它们进行了室温伽马射线辐射处理,重点研究了这些材料的电性能和自发热性能,利用DSC、SEM、WAXS、DMA和体积膨胀等仪器进行了一系列测试表征。结果表明,NiCF作为导电填料时体系的逾渗阈值最低,为3vol%。伽马射线辐射处理不仅能有效提高材料的PTC效应,而且在合适的辐射剂量时也能有效提高材料的自发热性能。对材料介电性能的研究揭示了材料的交流电阻率与温度、频率的依赖关系。 相似文献
14.
Polyethylene-polyethylene blend films were prepared by gelation/crystallization from semidilute solution by using ultrahigh molecular-weight (mw) polyethylene (UHMWPE) (mw=6×106) and low molecular weight polyethylene (LMWPE) (mw=4×104). The UHMWPE/LMWPE compositions chosen were 50/50, 67/33, and 91/9. Elongation was carried out in a hot oven at 115–130°C. The drawn films were exposed to an electron beam under nitrogen flow. Radiation doses chosen were 10, 20, 40, and 100 Mrad. crosslinking caused a significant effect in improving high temperature resistance for the blend film with draw ratio of 20 in the case of irradiation doses less than 20 Mrad. The elongation beyond 20 times and high doses beyond 20 Mrad hampered the crosslinking effect and the specimens were easily torn manually. This is thought to be due to the fact that the excess irradiation dose causes main chain scission apart from crosslinking. 相似文献
15.
Qingyun Chen Ying Xi Yuezhen Bin Masaru Matsuo 《Journal of Polymer Science.Polymer Physics》2008,46(4):359-369
Carbon fiber (CF) filled low‐molecular‐weight polyethylene (LMWPE) and ultra‐high molecular weight polyethylene (UHMWPE) composites were prepared by the gelation from solution and the kneading in the melting state. The content of carbon fibers was fixed to be 23.5 vol %. The resistivity, positive temperature coefficient (PTC), and dielectric behaviors of the composites became more pronounced with increasing content of LMWPE with much higher thermal expansion than that of UHMWPE. The PTC effect became most significant, when the blend ratio of LMWPE to UHMWPE was 9/1. Beyond 9/1, the PTC effect was less pronounced. Scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) revealed that the UHMWPE and LMWPE chains within the composite crystallized independently by gelation from solution and were virtually unaffected by the presence of carbon fibers. Consequently, it was confirmed that carbon fibers selectively were localized in the mixed region of LMWPE and UHMWPE for the composite (3/1 and 6/1) and mainly in the region of LMWPE for the 9/1, 12/1, and 15/1 composites. This indicated that the content of carbon fibers within LMWPE region was the highest for the 9/1 composite and the 9/1 composite provides the most significant PTC effect. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 359–369, 2008 相似文献
16.
Wiriya Thongruang C. Maurice Balik Richard J. Spontak 《Journal of Polymer Science.Polymer Physics》2002,40(10):1013-1025
Conductive polymer composites possessing a low percolation‐threshold concentration as a result of double percolation of a conductive filler and its host phase in an immiscible polymer blend afford a desirable alternative to conventional composites. In this work, blends of high‐density polyethylene (HDPE) and ultrahigh molecular weight polyethylene (UHMWPE) were used to produce ternary composites containing either carbon black (CB), graphite (G), or carbon fiber (CF). Blend composition had a synergistic effect on electrical conductivity, with pronounced conductivity maxima observed at about 70–80 wt % UHMWPE in the CB and G composites. A much broader maximum occurred at about 25 wt % UHMWPE in composites prepared with CF. Optical and electron microscopies were used to ascertain the extent to which the polymers, and hence filler particles, are segregated. Differential scanning calorimetry of the composites confirmed that the constituent polymers are indistinguishable in terms of their thermal signatures and virtually unaffected by the presence of any of the fillers examined here. Dynamic mechanical analysis revealed that CF imparts the greatest stiffness and thermal stability to the composites. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1013–1023, 2002 相似文献
17.
The morphology, crystallization behavior, and properties of an impact-modified polypropylene (PP) copolymer with or without
sodium benzoate were investigated. The contents of ethylene–propylene rubber (EPR) in the reactor-made PP copolymer is about
15 wt%. For comparison, blends of PP and EPR containing the same EPR composition were prepared by melt-mixing. Morphological
studies by scanning probe microscopy indicated that the impact-modified copolymer consists of three different phases, i.e.,
polyethylene, PP, and EPR phases, which is considerably different from the morphology of the conventional PP/EPR blend of
the corresponding composition. The impact-modified PP copolymer exhibited a higher crystallization rate in terms of the lower
crystallization half-time and thus higher thermal and mechanical properties, such as impact strength and hardness, than the
PP/EPR blend did. The addition of sodium benzoate as a nucleating agent to the copolymer increased the crystallization rate
and the mechanical properties.
Received: 4 June 2001 Accepted: 31 October 2001 相似文献
18.
The melting and the crystallization of blends of ultra-high molecular weight polyethylene (UHMWPE) and polyethylene high density with normal molecular weight (NMWPE) are investigated by means of differential scanning calorimetry (DSC). Mixing the components at a temperature below the flow temperature of UHMWPE (215 °C) results in segregated melting and crystallization. The segregated melting and crystallization temperatures of both components do not depend on composition of the blend. The extreme enthalpy dependence on blend composition is explained in terms of mutual influence exhibited by the components with respect to each other. It is due to the inner stresses in nonflowing UHMWPE characterized with a lot of entangled tie molecules. Mixing the components above the flow temperature of UHMWPE results in only one peak of melting and crystallization respectively. Complete mixing and probably co-crystallization between the components takes place on mixing NMWPE with flowing UHMWPE. 相似文献
19.
Aqueous polysaccharide blends based on hydroxypropyl guar gum and carboxymethyl cellulose: synergistic viscosity and thixotropic properties 总被引:1,自引:0,他引:1
Aqueous polysaccharide blends, formed from 2.5% (w/v) solution of hydroxypropyl guar gum (HPG) and 2.5% (w/v) solution of carboxymethyl cellulose (CMC) according to different blending ratios, were investigated at 20 °C in terms of their shear-dependent viscosity and thixotropic properties. The Cross viscosity equation was found to fit the shear-dependent viscosity data with reasonable accuracy. When the HPG solution with the mass fraction (f
HPG) of 0.87 was mixed, the zero shear viscosity (η
o) of the corresponding blend was found to be 168.5753 Pa s, while the η
o values of component HPG and CMC solutions were found to be 3.3859 and 98.6525 Pa s, respectively. For the aqueous HPG/CMC blends investigated, the resulting zero shear viscosity was observed to be much greater than the combined zero shear viscosity of the component polysaccharide solutions, showing a synergistic viscosity property. The quantitative determination of the hysteresis loop area, developed during viscometer tests on shear rate–shear stress reverse paths, was used to describe the thixotropic behavior. When compared with aqueous solutions of the component polysaccharides, these polysaccharide blends could afford enhanced thixotropic property. Maximum thixotropy synergism was observed for the HPG/CMC blend with the f
HPG of 0.67. 相似文献
20.
A significant reduction in melt viscosity of ultrahigh molecular weight polyethylene (UHMWPE) was obtained by blending with polypropylene (PP) and poly(ethylene glycol) (PEG). The mechanism of viscosity reduction was investigated from the view of disentanglement effect. Dynamic mechanical analysis indicated that the pseudoequilibrium modulus (E′) of UHMWPE/PP(80/20) blend in the rubbery plateau was much lower than that of UHMWPE. Accordingly, the calculated entanglement density (νe) of UHMWPE/PP (80/20) blend was smaller than that of UHMWPE. Further reduction in E′ and νe of the blend was obtained by the incorporation of 1 phr PEG. Slow DSC analysis showed that the high temperature endotherm and exotherm for UHMWPE at slow temperature ramp diminished and increased, respectively when 5 phr PEG was added. It also revealed that the entanglement level of UHMWPE decreased with the addition of a small amount of PEG. 相似文献