Characterization of the free volume in high‐impact polystyrene/polypropylene and high‐impact polystyrene/high‐density polyethylene blends probed by positron annihilation spectroscopy

Hu, Youhua; Qi, Chenze; Liu, Weiming; Wang, Boyu; Zheng, Houtian; Sun, Xudong; Zheng, Xiaoming

doi:10.1002/app.2379

Cited by 23 publications

(10 citation statements)

References 16 publications

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“…It has been reported that as the alkyl branches of α‐olefins are increased, there is an increase in the amorphous phase free volume and in the interfacial surface area, leading to plasticization 38–40. Qi et al41 showed that the free‐volume holes in semicrystalline polymers (e.g., polypropylene and high‐density polyethylene) are not large enough to accommodate the branched chains and end groups of the macromolecular chains in high‐impact polystyrene (HIPS) to produce favorable interactions between the semicrystalline polymers and the HIPS polymer, and thus immiscible blends are formed. As the filler size decreases, the interfacial area between the fillers and the polymer matrix increases dramatically; the increasing interfacial area can influence the chain mobility and results in a depression of T g .…”

Section: Resultsmentioning

confidence: 99%

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Effect of nanoscale diamondoids on the thermomechanical and morphological behaviors of polypropylene and polycarbonate

Ghosh

Sciamanna

Dahl

et al. 2007

J Polym Sci B Polym Phys

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Nanoscale MolecularDiamond products (various diamondoid materials), obtained from petrochemical feedstocks, have been investigated as additives for polypropylene and polycarbonate. Three of the homologues of this family (diamantane, triamantane, and the [121]tetramantane isomer) have marginal effects on the thermal and mechanical properties of nonpolar/semicrystalline polypropylene. Mixtures of methylated tetramantane nanofillers also increase the stress-strain behavior of polypropylene composites without significantly impacting their glass transition temperatures. The addition of the selected diamondoids to amorphous/moderately polar polycarbonate increases the polymer tensile modulus significantly with marginal increases in the yield stress. The effects of the selected diamondoids on the thermal stability, crystallinity, and optical properties of polypropylene and polycarbonate are also reported. The results for the mechanical properties show that the selected diamondoids behave as plasticizers in polypropylene, whereas in polycarbonate, they act as antiplasticizers without adversely affecting the optical clarity.

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Section: Resultsmentioning

confidence: 99%

“…The free‐volume size in the polypropylene molecules is not sufficiently large to accommodate the large and rigid diamondoid molecules. As the alkyl branches of α‐olefins are increased, there is an increase in the free volume in the amorphous phase and interfacial surface area, leading to the plasticization 38–41…”

Section: Discussionmentioning

confidence: 99%

Effect of nanoscale diamondoids on the thermomechanical and morphological behaviors of polypropylene and polycarbonate

Ghosh

Sciamanna

Dahl

et al. 2007

J Polym Sci B Polym Phys

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“…The longest lived component of the positron lifetime spectra, τ 3 , and the corresponding o ‐Ps intensity, I 3 , are correlated with the mean radius ( R ) and the relative number of free volume cavities in the polymer material, respectively. A mixture of polymers with different structures of lateral groups and condensed states usually results in an obvious change in blend properties of the polymers . Results (Fig.…”

Section: Resultsmentioning

confidence: 99%

Effect of confinement on glass dynamics and free volume in immiscible polystyrene/high‐density polyethylene blends

Zhu

Liao

et al. 2015

Polymer International

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The effect of confinement on glass dynamics combined with the corresponding free volume changes of amorphous polystyrene (PS) in blends with semi-crystalline high-density polyethylene (HDPE) have been investigated using thermal analyses and positron annihilation lifetime spectroscopy (PALS). Two different glass transition temperatures (T g ) were observed in a PS/HDPE blend due to the dissimilarity in the chemical structure, consistent with an immiscible blend. However, T g of PS in the incompatible PS/HDPE blend showed an upward trend with increasing PS content resulting from the confinement effect, while T g of the semi-crystalline HDPE component became lower than that of neat HDPE. Moreover, the elevation of T g of PS was enhanced with a decrease of free volume radius by comparing annealed and unannealed PS/HDPE blends. Positron results showed that the free volume radius clearly decreased with annealing for all compositions, although the free volume hole size agreed well with linear additivity, indicating that there was only a weak interaction between the two components. Combining PALS with thermal analysis results, the confinement effect on the glass dynamics and free volume of PS phase in PS/HDPE blends could be attributed to the shrinkage of HDPE during crystallization when HDPE acted as the continuous phase.

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“…It has been considered that such kind of impurities or contaminant would affect the mechanical properties deteriorate of the recycled plastic materials, however, quantitative investigations on the validity of contamination in order to use the recycled material as the desired performance has not been conducted sufficiently. 2,[7][8][9][10] In OA equipments, casing plastic materials often contact with gear wheal, at that place, grease is commonly used in order to avoid abrasion by friction. As the result, the recycled plastic casing is possibly adhered with grease, and it is difficult to remove the grease because of its high viscosity.…”

Section: Introductionmentioning

confidence: 99%

Miscibility and Mechanical Properties of High-Impact Polystyrene Blended with Poly(α-olefin) Grease

Inomata

Ogiso

Kobayashi

et al. 2011

J. Soc. Rheol., Jpn

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Small amount of impurities or contaminations in recycled plastic have a possibility to influence on mechanical properties of product. In this study, miscibility and mechanical properties of melt-blended high-impact polystyrene (HIPS) and poly(a-olefin) (PO)-based grease have been investigated. We have focused attention on the molecular weight (M w ) of PO, and the range of M w for PO in the used greases was 690-8,500. Changes of glass transition temperature were observed for polystyrene and polybutadiene phases in the HIPS/grease blends, that indicated small amount of PO was solubilized into HIPS. When M w of PO was higher than 5,000, insoluble excess PO acted as lubricant, and sample preparation was difficult since slipping between the polymer and chamber wall or screw occurred during melt blending. By this limitation in solubility of HIPS/grease, depression of mechanical properties such as flexural modulus and strength for the obtained blends was not remarkable. On the other hand, blends with high grease content could be obtained for PO with low M w because of its good solubility with HIPS, as the result, their flexural properties were highly deteriorated than the original HIPS. Therefore, the grease containing high molecular weight PO has a smaller influence on the mechanical properties of HIPS/grease because of the limitation in solubility. Results of chemical stress crack tests for HIPS/grease were also explained by the miscibility of PO with HIPS.

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Characterization of the free volume in high‐impact polystyrene/polypropylene and high‐impact polystyrene/high‐density polyethylene blends probed by positron annihilation spectroscopy

Cited by 23 publications

References 16 publications

Effect of nanoscale diamondoids on the thermomechanical and morphological behaviors of polypropylene and polycarbonate

Effect of nanoscale diamondoids on the thermomechanical and morphological behaviors of polypropylene and polycarbonate

Effect of confinement on glass dynamics and free volume in immiscible polystyrene/high‐density polyethylene blends

Miscibility and Mechanical Properties of High-Impact Polystyrene Blended with Poly(α-olefin) Grease

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