Quantification of the Young's modulus for polypropylene: Influence of initial crystallinity and service temperature

Li, Jiquan; Zhu, Zhiwei; Li, Taidong; Peng, Xiang; Jiang, Shaofei; Turng, Lih‐Sheng

doi:10.1002/app.48581

Cited by 32 publications

(26 citation statements)

References 44 publications

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“…It has been shown that the degree of crystallinity is linked to the Young's modulus. [ 28,53 ] As shown in Figure S3, the maximum level of both responses was achieved at 30 mm/s. This could be related to the fact that this speed gives enough time to PPS chains to organize into crystalline regions, resulting in a high elastic behavior of the parts.…”

Section: Resultsmentioning

confidence: 94%

Experimental investigation and optimization of printing parameters of3Dprinted polyphenylene sulfide through response surface methodology

Magri

Mabrouk

Vaudreuil

et al. 2020

J of Applied Polymer Sci

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Today fused filament fabrication is one of the most widely used additive manufacturing techniques to manufacture high performance materials. This method entails a complexity associated with the selection of their appropriate manufacturing parameters. Due to the potential to replace poly-ether-etherketone in many engineering components, polyphenylene sulfide (PPS) was selected in this study as a base material for 3D printing. Using central composite design and response surface methodology (RSM), nozzle temperature (T), printing speed (S), and layer thickness (L) were systematically studied to optimize the output responses namely Young's modulus, tensile strength, and degree of crystallinity. The results showed that the layer thickness was the most influential printing parameter on Young's modulus and degree of crystallinity. According to RSM, the optimum factor levels were achieved at 338 C nozzle temperature, 30 mm/s printing speed, and 0.17 mm layer thickness. The optimized post printed PPS parts were then annealed at various temperatures to erase thermal residual stress generated during the printing process and to improve the degree of crystallinity of printed PPS's parts. Results showed that annealing parts at 200 C for 1 hr improved significantly the thermal, structural, and tensile properties of printed PPS's parts. K E Y W O R D S crystallization, glass transition, mechanical properties, thermal properties 1 | INTRODUCTION Fused deposition modeling (FDM), also called fused filament fabrication (FFF), is a very popular additive manufacturing (AM) technology for its simplicity and low investment costs. [1] It relies on the deposition of a liquefied thermoplastic polymer filament in a layer upon layer manner. The precise control of the extruder head enables direct fabrication of three-dimensional complex geometries from a computer-aided design (CAD) system. FFF often considers as a simple and efficient process to print commodity polymers, such as polylactic acid (PLA), acrylonitrile butadiene styrene, polycarbonate, and highdensity polyethylene due to their low cost and simple operation. [2-7] However, when applied to manufacture high performance thermoplastics (HPT), the FFF equipment faces a number of challenges to achieve optimized results for both material properties and part quality. Among these challenges, high melting temperature, large thermal expansion, and large temperature gradient are

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Section: Resultsmentioning

confidence: 94%

Experimental investigation and optimization of printing parameters of3Dprinted polyphenylene sulfide through response surface methodology

Magri

Mabrouk

Vaudreuil

et al. 2020

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…The crystallinities of each layer in the model were obtained by measuring the corresponding positions of molded parts with WAXD. The mechanical properties of each layer necessary for prediction were calculated using the following model describing the elastic modulus with the influence of temperature and crystallinity [ 24 ].

where θ 0 is the reference temperature (room temperature); E 0 is the elastic modulus at the reference temperature; a , b , and c are material parameters; w and θ are the crystallinity and service temperature, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…The thicknesses of the multi-layers were determined as the thicknesses of the skin-core structure in the molded parts, measured using a polarizing microscope (PLM). A model was introduced to describe the elastic modulus with the influence of temperature and crystallinity [ 24 ]. Finally, the predicted results were compared with the warpage information of the parts obtained using a 3D laser scanner.…”

Section: Introductionmentioning

confidence: 99%

Warpage Prediction of RHCM Crystalline Parts Based on Multi-Layers

Bei

Liu

et al. 2021

Polymers

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Warpage is a typical defect for injection-molded parts, especially for crystalline parts molded by rapid heat cycle molding (RHCM). In this paper, a prediction method is proposed for predicting the warpage of crystalline parts molded by the RHCM process. Multi-layer models were established to predict warpage with the same thicknesses as the skin-core structures in the molded parts. Warpages were defined as the deformations calculated by the multi-layer models. The deformations were solved using the classical laminated plate theory by Abaqus. A model was introduced to describe the elastic modulus with the influence of temperature and crystallinity. The simulation process was divided into two procedures, before ejection and after ejection. Thermal stresses and thermal strains were simulated, respectively, in the procedure before ejection and after ejection. The prediction results were compared with the experimental results, which showed that the average errors between predicted warpage and average experimental warpage are, respectively, 7.0%, 3.5%, and 4.4% in conventional injection molding (CIM), in RHCM under a 60 °C heating mold (RHCM60), and in RHCM under a 90 °C heating mold (RHCM90).

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“…In Thomason et al's study, the test is performed from 233 K. However, the matrix Young's modulus below room temperature used in the model predictions is not obtained. Li et al [52] provided the Young's modulus of PP with different crystallinity values above room temperature. We use these values to predict the ISS at elevated temperature, respectively, and then the average values are taken.…”

Section: Fiber Agglomerationmentioning

confidence: 99%

Theoretical characterization of the temperature‐dependent ultimate tensile strength of short‐fiber‐reinforced polymer composites

Yang

Liu

et al. 2021

Polymer Composites

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Short fiber/polymer composites (SFPCs) are increasingly applied in the field of high-temperature structures. Its reliability at high temperatures has always been the core issue concerned by researchers. Here, utilizing the Force-Heat Equivalence Energy Density Principle, we developed a physically based model of temperature-dependent ultimate tensile strength (TDUTS) for SFPCs. This model quantitatively considers the evolution of residual thermal stress, interface, fiber, and matrix performance as temperature increases. Meanwhile, the influence of fiber agglomeration frequently observed in composites and fiber orientation and length distribution is taken into account in the proposed model. The model predictions over a wide temperature range are validated against the experimental data available from the literature, indicating its reasonability and accuracy. The comparison with Kelly-Tyson model and Li's model is also performed. Additionally, the quantitative effects of the fiber agglomeration and interfacial shear strength on the TDUTS are discussed in detail. The present research not only provides an accurate and feasible approach to estimate the TDUTS of SFPCs, but also offers some helpful insights for the fabrication and design of such composites.

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Quantification of the Young's modulus for polypropylene: Influence of initial crystallinity and service temperature

Cited by 32 publications

References 44 publications

Experimental investigation and optimization of printing parameters of3Dprinted polyphenylene sulfide through response surface methodology

Experimental investigation and optimization of printing parameters of3Dprinted polyphenylene sulfide through response surface methodology

Warpage Prediction of RHCM Crystalline Parts Based on Multi-Layers

Theoretical characterization of the temperature‐dependent ultimate tensile strength of short‐fiber‐reinforced polymer composites

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