https://espace.library.uq.edu.au/view/UQ:08f48a6/UQ08f48a6_OA.pdf

Degradation and stabilization of polyurethane elastomers

Tuning nanophase separation behavior in segmented polyhydroxyurethane via judicious choice of soft segment

Correlation between the micro-structure and macroscopic mechanical properties of GAP-based propellant during aging

The cavity beneath the pavement will be further expanded by the self-expansion pressure of polyurethane foam after grouting, leading to a decline in its density and mechanical properties of the polyurethane foam. This study proposed a cavity expansion model that coupled the influence of expansion characteristics of polyurethane foam and the mechanical behavior of surrounding soil, thus, the cavity expansion performance with declining expansion pressure and changing mechanical parameters in confined soil and pavement was accurately characterized. The study sequences are as follows: (1) a series of confined expansion tests and uniaxial compression tests were conducted via a self-developed device under various densities and material ratios of the polyurethane foam, thus the prediction formula of expansion pressure with material ratio and density was obtained, and the variation of the ultimate compressive strength and elastic modulus of polyurethane foam can also be quantified; (2) a cavity expansion model considering the decrease of expansion pressure and compressive strength of polyurethane foam during the expansion was proposed based on the combination of the conventional cavity expansion model and the conducted expansion test results; (3) the parametric analysis was conducted to investigate the influence of the initial density (ρ0, refers to the density when the self-expansion pressure starts to apply on the surrounding soil), material ratio of polyurethane foam and the original cavity size on the expansion radius, so the evolution of mechanical properties after cavity expansion under the pavement was revealed based on the density change after expansion (ρ). The feasibility of the improved model for the expansion of polyurethane foam in soil was evaluated in this study, which can provide a reference for the design and optimization of a polyurethane foam filling scheme for the cavity underneath a pavement. 

The expansion and mechanical property-based cavity expansion model for polyurethane grouting underneath the airport pavement

In order to design and fabricate hydrophobic, durable and anti-icing coating for aircraft, a polyurethane elastomer matrix was hydrophobically modified and incorporated with fluorinated SiO2 nanoparticles to prepare a micro/nanostructured coating. The micro/nanostructured coating with low surface energy displayed significantly improved mechanical properties and hydrophobicity, which exhibited the water contact angle of 162° as well as the sliding angle of 2°. The coating is highly stretchable, which could sustain large-scale extension, and exhibits tensile strength and elongation at break up to 16.22 MPa and 385%, respectively. Furthermore, the coating exhibited a remarkably weak ice adhesion strength of 14.33 kPa, on which the accumulative ice is prone to fall off under natural wind and its own weight. The coating sustained long-term superhydrophobic properties and anti-icing performance even after 1000 abrasion cycles. The proposed method for the production of scalable superhydrophobic coating is cost-effective and can be applied in aerospace and automotive anti-icing systems.

Fabrication of a durable anti-icing composite coating based on polyurethane elastomer and silica nanoparticles

To study the tensile properties of GAP/CL-20/HMX (GCH) propellant, a new generation high energy solid propellant, uniaxial tensile test and dynamic mechanical analysis (DMA) test were performed at different temperatures (233.15–333.15 K) and strain rates (0.000476–0.9524 s−1). The experimental results show that, unlike Hydroxyl-terminated Polybutadiene (HTPB) and Nitrate Ester Plasticized Polyether (NEPE) propellants, GCH propellant have special arc section in the initial tensile stage at room temperature and high temperature. This phenomenon may be caused by the stretching of the curled molecular chains. The variation of mechanical properties shows that the maximum tensile strength and initial elastic modulus increase with the decrease of temperature and the increase of strain rate. The variation of maximum elongation is complex, which increases with the increase of strain rate at room temperature and high temperature, and first increases then decreases with the increase of strain at low temperature. The constitutive model of the GCH propellant was established by introducing the chain extension and the debonding damage thresholds. Both of which show a linear double logarithmic increasing trend with the increase of strain rate at room and high temperature. The latter shows a linear double logarithmic decrease trend with the increase of strain rate at the low temperature. 

Study on Tensile Mechanical Properties of GAP/CL‐20/HMX Propellant

A hydrogenated hydroxy-terminated butadiene–acrylonitrile copolymer (HHTBN)-based polyurethane elastomer (PUE) was prepared by using HHTBN as the soft segments in a casting method. The HHTBN-based PUE exhibited improved mechanical properties and aging resistance.

A hydrogenated hydroxy-terminated butadiene–acrylonitrile copolymer-based polyurethane elastomer with improved mechanical properties and aging resistance

The polyurethane has been successfully applied to reinforce the railway ballasted track and the bonding properties of the polyurethane to ballast particles have significant effects on track performance. However, the mechanical behaviors of the polyurethane-ballast bonds(PBBs) haven’t been reported leaving the particle scale mechanism of the polyurethane reinforcement still unclear. A novel laboratory experimental method was developed in this paper to characterize the mechanical behaviors of the PBBs. Using standard test specimens with various specimen size and bond thickness, a series of laboratory tests were conducted to measure the stress–strain responses of the PBBs under tensile, compressive and shear loadings. The measured results show that the stress of a PBB increases nonlinearly with its strain when it subjects to uniaxial tensile or compressive loads. The test results also validate that the strength envelope of a PBB follows the linear Mohr-Coulomb criterion. A modified parallel bond model was proposed to predict the nonlinear stress–strain behaviors of the PBB with high accuracy. Furthermore, it is found that the bond thickness has distinct effects on the tensile and the cohesion strength of the PBB but negligible effect on its friction angle. The initial tangent elastic modulus of the PBB increases approximately linearly with the increase of the bond thickness. The experimental method, results and the modified bond model introduced in this paper are very helpful for the performance evaluation and the numerical simulations of polyurethane reinforced ballast. 

A novel laboratory investigation to characterize the mechanical behaviors of polyurethane-ballast bonds under complex stress states

An Experimental Study to Identify the Micro-Mechanical Parameters of the Bonds in the Polyurethane Stabilized Ballast

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

Xu Zhang

Author Tools

Chat about Author

Papers

Study on Tensile Mechanical Properties of GAP/CL‐20/HMX Propellant

A hydrogenated hydroxy-terminated butadiene–acrylonitrile copolymer-based polyurethane elastomer with improved mechanical properties and aging resistance

A novel laboratory investigation to characterize the mechanical behaviors of polyurethane-ballast bonds under complex stress states

An Experimental Study to Identify the Micro-Mechanical Parameters of the Bonds in the Polyurethane Stabilized Ballast