ZHAO JUN^a, LIU AIQIN^a, ZHOU HONG^a, LUO JUN^b,*, AND LIU YUAN^b,*

Journal of Polymer Materials, Vol.37, No.1-2, pp. 29-42, 2020, DOI:10.32381/JPM.2020.37.1-2.3

Abstract Heteroatoms (N, O, and F) and hydrogen groups are important elements for forming the H-bonds. It is well known that a large number of hydrogen groups are formed after curing reaction of epoxy. However, literatures about epoxy resins containing heteroaromatic ring and the H-bonds after cure reaction of the epoxy resins are seldom published. To bridge the gap, a kind of new epoxy monomer containing pyridine ring (EMP) has been synthesized in this work, andit is further cured by 4,4-diaminodiphenyl methane (DDM). The properties of cured EMP/ DDM are evaluated by DSC, DMA, and static contact angle measurement. Moreover, the… More >

JITENDRA. S. TATE^1,2,*, HARISH KALLAGUNTA^1,2, ANDREW ALVAREZ¹

Journal of Polymer Materials, Vol.38, No.1-2, pp. 101-120, 2021, DOI:10.32381/JPM.2021.38.1-2.9

Abstract The exponential growth in composites and their increased use in military, aerospace, energy, and automotive industry is driven by their high performance and light weight. High performance thermosetting polymers such as cyanate ester have received considerable attention due to its ability of volatile-free curing. It also offers advantages such as excellent radiation shielding, high thermal stability, and hydrophobicity with lots of potential for enhanced mechanical strength. This research article discusses the results of effects of multiwalled carbon nanotubes (MWCNT) at predetermined loading levels of 0.5wt%, 1wt% and 1.5wt% on mechanical, thermal and flammability properties of cyanate ester modified carbon fiber… 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 >

Oulfa Harrat^1,*, Yazid Hadidane¹, S. M. Anas^2,*, Nadhim Hamah Sor^3,4, Ahmed Farouk Deifalla⁵, Paul O. Awoyera⁶, Nadia Gouider¹

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 3435-3465, 2024, DOI:10.32604/cmes.2023.044950

Abstract Given their numerous functional and architectural benefits, such as improved bearing capacity and increased resistance to elastic instability modes, cold-formed steel (CFS) built-up sections have become increasingly developed and used in recent years, particularly in the construction industry. This paper presents an analytical and numerical study of assembled CFS two single channel-shaped columns with different slenderness and configurations (back-to-back, face-to-face, and box). These columns were joined by double-row rivets for the back-to-back and box configurations, whereas they were welded together for the face-to-face design. The built-up columns were filled with ordinary concrete of good strength. Finite element models were applied,… More > Graphic Abstract

Jing Yu¹, Jie Ren², Guangming Shen³, Weixiang Sun², Hui Wang^4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.9, pp. 2385-2398, 2023, DOI:10.32604/fdmp.2023.027877

Abstract In this paper, the influence of NaCl freeze-thaw (F-T) cycles and dry-wet (D-W) alternations on the flexural, compressive and bonding strengths of alkali-activated fly ash (FA) and a blast furnace slag powder (BFS) is investigated. The considered NaCl concentration is 3%. The effect of polypropylene fibers on the mechanical strengths is also examined. Scanning electron microscopy (SEM), thermogravimetry (TG) and X-ray diffraction (XRD) are selected to discern the mechanisms underpinning the NaCl-induced erosion. The obtained results indicate that the best results in terms of material resistance are obtained with admixtures containing 60% BFS and 40% FA in terms of mass… More >

Yihan Sun^1,2, Lihua Chu³, Yudong Cheng^4,*, Fengxia Chi^1,2, Chenchen Zhang^1,2, Pengcheng Sun^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 2171-2180, 2023, DOI:10.32604/fdmp.2023.026892

Abstract In general, acid aggregates are not used in combination with asphalt concrete because of their poor compatibility with the asphalt binder, which typically results in a scarce water stability of the concrete. In the present study, the feasibility of a new approach based on the combination of acid granite fine aggregate with alkaline limestone coarse aggregate and Portland cement filler has been assessed. The mineral and chemical compositions of these three materials have first been analyzed and compared. Then, the effect of different amounts of Portland cement (0%, 25%, 50%, 75% and 100% of the total filler by weight) on… More >

Peng Zhang^1,2, Wenshuai Wang¹, Yuanxun Zheng^1,*, Shaowei Hu^2,3

Journal of Renewable Materials, Vol.11, No.4, pp. 1853-1879, 2023, DOI:10.32604/jrm.2023.024981

Abstract Using recycled aggregate (RA) and slag instead of natural aggregate (NA) and cement can reduce greenhouse gas emissions (GHGE) and achieve effective waste recovery. In recent years, RA has been widely used to replace NA in concrete. Every year, several researchers conduct investigations on the mechanical performance and durability of recycled aggregate concrete (RAC). Due to the loose and porous material properties of RA, the mechanical properties and durability of RAC, such as strength, carbonation resistance, permeability resistance and chloride ion penetration resistance, are greatly reduced compared with natural aggregate concrete. In contrast, concrete containing slag instead of NA and… More >

Henghui Deng^1,2, Jingyi Lu^1,2, Dunsheng Liang^1,2, Xiaomin Wang^1,2, Tongyao Wang^1,2, Weihao Zhang^1,2, Jing Wang^3,*, Chaoqun Zhang^1,2,*

Journal of Renewable Materials, Vol.11, No.3, pp. 1209-1222, 2023, DOI:10.32604/jrm.2022.023371

Abstract In this study, acrylic acid was used as a neutralizer to prepare bio-based WPU with an interpenetrating polymer network structure by thermally induced free radical emulsion polymerization. The effects of the content of acrylic acid on the properties of the resulting waterborne polyurethane-poly (acrylic acid) (WPU-PAA) dispersion and the films were systematically investigated. The results showed that the cross-linking density of the interpenetrating network polymers was increased and the interlocking structure of the soft and hard phase dislocations in the molecular segments of the double networks was tailored with increasing the content of acrylic acid, leading to enhancement of the… More > Graphic Abstract

Claudio Del Menezzi^1,2,3, Antonio Pizzi^2,*, Siham Amirou², Xuedong Xi^4,5

Journal of Renewable Materials, Vol.11, No.2, pp. 539-553, 2023, DOI:10.32604/jrm.2022.024971

Abstract

This article presents the first applied results of using citric acid in combinations with a melamine-urea-formaldehyde (MUF) resin for bonding wood veneers. The chemical reactions involved are shown based on a MALDI ToF analysis of the reaction of the MUF resin with citric acid. The preliminary results of the physical and mechanical properties of the LVL prepared are also presented. Veneers from Populus sp were used to manufacture 5-layer laminated veneer lumber (LVL) of small dimensions. Five combinations of the amount of citric acid, MUF spread rate and pressing parameters were tested. LVL bonded with 20% of citric acid +… More > Graphic Abstract

Jingjing Liao^1,2, Jinxing Li², Fuxian Yang², Yan Zhu², Hongyan Wang³, Guanben Du^1,2,*, Hisham Essawy⁴, Xiaojian Zhou^2,*

Journal of Renewable Materials, Vol.10, No.2, pp. 359-372, 2022, DOI:10.32604/jrm.2021.016335

Abstract Polyvinyl alcohol (PVA)-based films containing Chinese bayberry tannin (BT) were prepared by cross-linking using glyoxal, glutaraldehyde and dialdehyde starch, individually. The presence of cross-linkers was evident to promote the transparency and decrease the moisture content of PVA/BT films, while the water solubility stayed almost unchanged in the cross-linked PVA/BT films. All cross-linkers provided promotion of the water vapor permeability, mechanical property and thermal stability of PVA/BT films. The best water vapor barrier capacity was found in case of glutaraldehyde cross-linked PVA/BT film, while the highest tensile strength was encountered in case of glyoxal cross-linked PVA/BT films, compared with the uncross-linked… More > Graphic Abstract