RAVI KUMAR, VISHWA PRATAP SINGH, MADHUKAR PRAJAPATI, ASHWITH, PRIYANKA SINGH, SATYAJIT SAMANTA, SAIKAT BANERJEE^*

Journal of Polymer Materials, Vol.36, No.4, pp. 323-335, 2019, DOI:10.32381/JPM.2019.36.04.3

Abstract Types of nucleating agents and their dosage level play an important role on the crystallinity of the polymer which controls the final properties like optical clarity, stiffness and reduced cycle time during molding. In this study, the efficiency of two different types of commercially available nucleating agents, phosphate ester and dicarboxylic acid based, have been studied. Both the nucleating agents were compounded with molding grade polypropylene homopolymer having melt flow index (MFI) of 12 g/10min at 2.16 Kg and 230°C, in a co-rotating twin screw extruder at two different dosage level, i.e. 300 ppm and 600 ppm. The effectiveness of… More >

ZHIHUI HUANG¹, JIAMIAO CHEN¹, YANPING HUO¹, JINGWEI ZHAO²

Journal of Polymer Materials, Vol.38, No.3-4, pp. 257-269, 2021, DOI:10.32381/JPM.2021.38.3-4.7

Abstract The effect of the ether/keto ratios on the thermal properties, mechanical performances and crystallization behavior of the Poly(aryl ether ketone)s (PAEK) were investigated. A formula was proposed the estimate the melting temperatures of the PAEKs with high accuracy. Glass transition temperatures were affected by the ether/keto ratios and molecular weights, and were related with the brittle-tough transition of the PAEKs. Mechanical performances of tensile, impact, flexural and compressive strength decreased with the increase of ether/keto ratios, while elongation had a trend of increase. The non-isothermal crystallization curves exhibited well linearity when treated with Jeziorny’s model, and two crystallization processes were… More >

NIKHIL R. MENE¹, SARITA KALLA^1,*, Z.V.P. MURTHY^1,*

Journal of Polymer Materials, Vol.39, No.3-4, pp. 307-323, 2022, DOI:10.32381/JPM.2022.39.3-4.9

Abstract Membrane distillation-crystallization (MDC) is presented as a novel technique in the treatment of waste concentrated water which produces valuable crystals along with pure water. In the present study, multi-walled carbon nanotubes (MWCNT)/polyvinylidene fluoride (PVDF) flat sheet membranes were prepared via the wet phase inversion method and applied in MDC for the treatment of pharmaceutical waste. The pure and modified membrane surface properties are characterized with the help of SEM, FTIR, and contact angle measurement. The present work reported the effect of MWCNT content and feed temperature on the MDCperformance and measured pure water flux and pharmaceutical compounds recovery. The observed… More >

Ruiqiong Wang¹, Tiantian Du², Jinchen Cao^2,*, Guoqiang Wang³

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 129-139, 2024, DOI:10.32604/fhmt.2024.047825

Abstract With the advancement of oilfield extraction technology, since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall, increasing the difficulty of crude oil extraction. In this paper, the mesoscopic dissipative particle dynamics method is used to study the mechanism of the crystallization and deposition adsorbed on the wall. The results show that in the absence of water molecules, the paraffin molecules near the substrate are deposited on the metallic surface with a horizontal morphology, while the paraffin molecules close to the fluid side are arranged in a vertical column morphology. In the emulsified system,… More >

Chunlei Ruan^1,2,*, Cengceng Dong¹, Kunfeng Liang³, Zhijun Liu¹, Xinru Bao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.138, No.3, pp. 3033-3049, 2024, DOI:10.32604/cmes.2023.030607

Abstract Using Euler’s first-order explicit (EE) method and the peridynamic differential operator (PDDO) to discretize the time and internal crystal-size derivatives, respectively, the Euler’s first-order explicit method–peridynamic differential operator (EE–PDDO) was obtained for solving the one-dimensional population balance equation in crystallization. Four different conditions during crystallization were studied: size-independent growth, size-dependent growth in a batch process, nucleation and size-independent growth, and nucleation and size-dependent growth in a continuous process. The high accuracy of the EE–PDDO method was confirmed by comparing it with the numerical results obtained using the second-order upwind and HR-van methods. The method is characterized by non-oscillation and high… More > Graphic Abstract

Qilin Xiong^1,2,*, Wen An^1,2, Chuanzhi Liu^1,2

The International Conference on Computational & Experimental Engineering and Sciences, Vol.25, No.3, pp. 1-1, 2023, DOI:10.32604/icces.2023.010044

Abstract Shear localization is an important failure mode, or even the dominant mode in metals at high-strain rates. However, it is a great challenge to accurately predict the occurrence and evolution of shear localization in metals at the high-strain rate deformation. Here, a dislocation-based crystal plasticity constitutive model with a crucial mechanism of shear instability, namely dynamic recrystallization, was developed. The evolution equations of dislocation density and grain size in the process of dynamic recrystallization were proposed and incorporated into the new constitutive model. The threshold of the stored energy in crystals was used as the criterion for the occurrence of… More >

Alicia Mujica-Garcia^1,2, Iván Navarro-Baena¹, José Maria Kenny^1,2, Laura Peponi^2,*

Journal of Renewable Materials, Vol.2, No.1, pp. 23-34, 2014, DOI:10.7569/JRM.2013.634130

Abstract The main aim of this research is the production of different biopolymeric fi bers by electrospinning and the determination of the optimum working parameters for each polymer analyzed. In particular, three different biopolymers have been studied: poly(lactic acid) (PLA), poly(ε-caprolactone) (PCL) and a synthesized poly(ester-urethane) based on a synthesized PLA-b-PCL-b-PLA tri-block copolymer. This research is focused on the analysis of the infl uence of the processing parameters, such as the concentration and fl ow-rate of the polymer solution and the applied voltage, as well as the physico-chemical properties of the polymers used, on the fi ber formation and crystallization behavior.… More >

Kang Xu, Tong Li, Gaofei Guan, Jianlong Qu, Zhen Zhao, Xinsheng Xu^*

CMES-Computer Modeling in Engineering & Sciences, Vol.130, No.2, pp. 987-1002, 2022, DOI:10.32604/cmes.2022.018128

Abstract By means of the local surface nanocrystallization that enables to change the material on local positions, an innovative embedded multi-cell (EMC) thin-walled energy absorption structures with local surface nanocrystallization is proposed in this paper. The local surface nanacrystallization stripes are regarded as the moving morphable components in the domain for optimal design. Results reveal that after optimizing the local surface nanocrystallization layout, the specific energy absorption (SEA) is increased by 50.78% compared with the untreated counterpart. Besides, in contrast with the optimized 4-cell structure, the SEA of the nanocrystallized embedded 9-cell structure is further enhanced by 27.68%, in contrast with… More >

Xu Yan¹, Changheng Liu², Liang Qiao¹, Kaili Zhu², Hongsheng Tan^1,*, Shuhua Dong¹, Zhitao Lin¹

Journal of Renewable Materials, Vol.10, No.4, pp. 1039-1048, 2022, DOI:10.32604/jrm.2022.017239

Abstract The crystallization behavior, crystal morphology and form, and viscoelastic behavior of poly(butylene succinate) (PBS) and coir fiber/PBS composites (CPB) were investigated by differential scanning calorimetry (DSC), polarized optical microscopy (POM), X-ray diffraction (XRD) and dynamic mechanical analysis (DMA). The results of DSC measurement show that the crystallization temperature increases with the filling of coir fibers. POM images reveal that the spherulitic size and crystallization behavior of PBS are influenced by the coir fibers in the composites. XRD curves show that the crystal form of pure PBS and CPB are remaining almost identical. In addition, the storage modulus of CPB significantly… More >

Michael R. Snowdon^1,2, Amar K. Mohanty^1,2, Manjusri Misra^1,2*

Journal of Renewable Materials, Vol.5, Suppl.1, pp. 94-105, 2017, DOI:10.7569/JRM.2017.634134

Abstract This article assesses the performance of a biobased carbon as a nucleator using common techniques to stimulate poly(lactic acid) crystallization and enhance the thermal stability of PLA during injection molding. The combination of a biodegradable plasticizer, poly(ethylene glycol) (PEG), along with biobased carbon-rich pyrolyzed biomass char residue and an industrially available microcrystalline talc, were tested for nucleating agent capabilities at additions of 10 wt%. Differential scanning calorimetry (DSC) data demonstrated that the inclusion of the plasticizer could increase the PLA crystalline content with further improvements when nucleating agent was present. With a higher mold temperature, the PLA crystallinity surpassed 40%… More >