Reactive Modification of Poly(ethylene terephthalate) and its Foaming Behavior

Liu, Haiming; Wang, Xiangdong; Liu, Wei; Liu, Bengang; Zhou, Hongfu; Wang, Wenzhao

doi:10.1177/026248931403300402

Cited by 23 publications

(16 citation statements)

References 34 publications

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“…The enhancement of the complex viscosity may be attributed to the presence of the branching structure and/or the crosslinking structure, which made HDPE interchain slippage difficult. Similar phenomenon was observed in other study [22]. Figures 6 and 7 show the relationships between the storage modulus (G') and frequency, as well as the relationships between the loss angle (tanδ) and frequency, respectively.…”

Section: Figure 7 Relationships Between Loss Angle (Tanδ) and Frequesupporting

confidence: 86%

Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO₂ as Blowing Agent

Zhou

Wang

et al. 2017

Cellular Polymers

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Different content of dicumyl peroxide (DCP) acting as a crosslinking agent was mixed with high-density polyethylene (HDPE) in a Haake internal mixer to improve the viscoelasticity and foamability of HDPE. The crosslinked HDPE samples were foamed in a high pressure stainless steel autoclave using CO 2 as the physical blowing agent. The molecular weight, crystallization behavior and rheological properties of various HDPE samples were examined by gel permeation chromatography, differential scanning calorimetry, rotational rheometer, and torque rheometer, respectively. The foaming properties of various samples were characterized by scanning electron microscope and densimeter. It was found that with the increasing content of DCP, the molecular weight, crystallization temperature, complex viscosity, and storage modulus of HDPE increased and the crystallization degree of HDPE decreased. When 0.2 phr of DCP was introduced into HDPE, the expansion volume ratio of HDPE showed the highest value, which could be more than 7 times.

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Section: Figure 7 Relationships Between Loss Angle (Tanδ) and Frequesupporting

confidence: 86%

Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO₂ as Blowing Agent

Zhou

Wang

et al. 2017

Cellular Polymers

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“…The melt elasticity could be characterized by the G' and tan δ. The G' increased and the tan δ decreased, indicating that the melt elasticity enhanced [23]. Figs.…”

Section: Rheological Propertymentioning

confidence: 87%

A cooling and two-step depressurization foaming approach for the preparation of modified HDPE foam with complex cellular structure

Wang

Ding

Zhao

et al. 2017

The Journal of Supercritical Fluids

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This article reports on the fabrication of modified high-density polyethylene (HDPE) foams with complex cellular structure (CCS) using supercritical CO 2 as a physical blowing agent by a cooling and two-step depressurization method. HDPE was modified by dicumyl peroxide (DCP) and carbon nanotubes (CNTs) to improve its viscoelasticity and foaming behavior. The gel content test demonstrated that the cross-linking structure formed in the modified HDPE samples. Compared with that of neat HDPE, the viscoelasticity of modified HDPE was improved largely, which was characterized by rotational rheometer and torque rheometer. The introduction of DCP and CNTs had a slightly effect on the thermal behaviors of HDPE. The foaming properties of various HDPE samples showed that the cross-linking structure caused by DCP improved the

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“…Liu et al [25] foamed PET with an initial IV value of 0.8 dl/g using autoclave batching foaming method and applied tetraglycidyl diamino diphenyl methane (TGDDM) as chain extender. The obtained foams had less than 0.07 g/cm 3 density and an average cell diameter of 86 µm.…”

Section: Xia Et Almentioning

confidence: 99%

“…The crystalline ratio of the modified RPET materials is lower than that of the initial material, due to the more difficult ordering of longer molecules and hence slower crystalline 12 nucleation. It is especially true for the material modified by multifunctional epoxide chain extender, even though it contains nucleating agent as well, in this case the obtained branching molecular structure hinders the assembly of PET chains into crystal lattices [25]. The melting peak temperature of RPET+ 1%CE+1% talc material shifted to lower temperature likely due to the nucleation effect of talc resulting thinner lamellae with lower melting temperature.…”

Section: Fig 3 Dsc Curves Of the Different Raw Materialsmentioning

confidence: 99%

Preparation of Low-Density Microcellular Foams from Recycled PET Modified by Solid State Polymerization and Chain Extension

et al. 2018

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Recycled polyethylene-terephthalate (RPET) bottle regrinds were physically foamed after two types of industrially feasible molecular weight increasing processes. Intrinsic viscosity (IV) of initial waste (0.71 dl/g) increased both after reactive extrusion carried out using a multifunctional epoxy-based chain extender (0.74 dl/g) and after solid state polycondensation (SSP) (0.78 dl/g), while capillary rheometry revealed higher degree of branching in the chain extended PET material. Despite the relatively low IV values (below 0.80 dl/g), physical foaming, a mild and cost efficient way, was successful in both cases, uniform microcellular foam structures with void fractions ranging between 75 and 83% were achieved. During the experiments morphology change in the materials was tracked by differential scanning calorimetry (DSC) besides recording IV values. The IV drop during foaming was between 0.03-0.10 depending on the pre-processing technology. Structure of 2 foams produced from the two different modified RPET materials was compared with each other based on scanning electron microscopic imaging (SEM) of cryogenic fracture surfaces.The average cell diameters were measured to be 213 and 360 µm in the case of chain extended and SSP-modified materials, respectively.

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Reactive Modification of Poly(ethylene terephthalate) and its Foaming Behavior

Cited by 23 publications

References 34 publications

Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO₂ as Blowing Agent

Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO₂ as Blowing Agent

A cooling and two-step depressurization foaming approach for the preparation of modified HDPE foam with complex cellular structure

Preparation of Low-Density Microcellular Foams from Recycled PET Modified by Solid State Polymerization and Chain Extension

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Reactive Modification of Poly(ethylene terephthalate) and its Foaming Behavior

Cited by 23 publications

References 34 publications

Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO2 as Blowing Agent

Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO2 as Blowing Agent

A cooling and two-step depressurization foaming approach for the preparation of modified HDPE foam with complex cellular structure

Preparation of Low-Density Microcellular Foams from Recycled PET Modified by Solid State Polymerization and Chain Extension

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Product

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Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO₂ as Blowing Agent

Preparation of Crosslinked High-density Polyethylene Foam Using Supercritical CO₂ as Blowing Agent