POLYMER ENGINEERING AND SCIENCE
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2025
·
IF 3.2
Min Xu,Jinrong Yin,Zhenyong Li,Yangqi Jiang,Opoku Bismark,Xiaoji Fu,Yu Song,Xianyan Ren,Yuwang Zhong
To solve the problem that the self-generated proppant in fractures grows slowly and cannot support the fractures in time, nano-graphite (NG) was introduced into a phase change liquid (PCL) composed of “styrene-divinylbenzene (SDB)” and the resulting self-generated proppants were constructed with a high growth speed. The NG/PCL started the phase transition from liquid to solid after 8 min at about 55°C in the wellbore section, and the phase transition was completed for only 2.5 min at a constant temperature of 65°C in fracture. Moreover, due to the high thermal conductivity and heterogeneous nucleation of the NG powder, the maximum strength of self-generated proppant in the NG-containing system can reach about 56.2 N during its growth process, which is 34.4% higher than that of pure SDB. The yield of the well-dispersed spherical self-generated proppants NG/SDB under the completely static condition can reach about 80%, of which the proppants with a particle size of 0.4 ~ 0.7 mm account for about 80%. NG/SDB exhibited an ultra-low apparent density of approximately 1.004 g/cm 3 , high compressive strength, and a crushing ratio of less than 1% at a closure pressure of 52 MPa, which is lower than that of commercial quartz sand and ceramsite proppants. Highlights Self-generated proppants with rapid growth were developed by the introduction of NG. Positive effects of NG in PCL system are obvious on phase transition and growth. NG/SDB is qualified in phase transition timing and compressive strength. The single-microsphere yield of NG/SDB is about 80%. The crushing ratio of NG/SDB as low as 3.92% at a closure pressure of 69 MPa.
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2017
·Vol. 57
·期 12
·1277-1284
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IF 1.449
Jia Qiu,Fei Liu,Junwu Zhang,Jing Chen,Haining Na,Jin Zhu
The controllable polyesters with high overall performance are obtained by tuning the stereostructure of 1,4-cyclohexylene ring moieties (CHRMs) in poly(butylene adipate- co −1,4-cyclohexanedicarboxylate) (PBAC). After increasing the number of irregular cis -CHRMs in the polyester, PBAC can transform from semicrystalline polymer to amorphous one. PBAC with 58% cis -CHRMs starts to exhibit good elasticity with shape recovery of 60% at 250% deformation, indicating the transition from plastic to thermoplastic elastomer. Through blending with polylactic acid (PLA), the elastic PBAC greatly enhances the impact strength of PLA to 7.5 kJ/m 2 . While the tensile elongation at break is dramatically improved to 161% with the addition of plastic PBAC. The mechanism related to the stereostructure of non-planar ring of PBAC on the properties of PLA is also analyzed. Therefore, this research suggests a particular way to build non-planar ring contained polyesters to modify PLA with high toughness. POLYM. ENG. SCI., 57:1277–1284, 2017. © 2017 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2016
·Vol. 56
·期 12
·1432-1436
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IF 1.719
Shiping Zhan,Nan Liu,Weijing Wang,Shuhua Chen,Jingchang Wang
To improve the properties of chitosan (CS) and poly(L-lactic acid) (PLLA) and obtain fully biodegradable materials, CS- g -PLLA copolymers were prepared using 1-(3-Dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)/N-hydroxyl succinimide (NHS) as a coupling agent. The copolymers were characterized by Fourier transform infrared analysis (FTIR), 1 H nuclear magnetic resonance ( 1 H NMR), elemental analysis, differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results obtained by FTIR and 1 H NMR showed that CS and PLLA were grafted successfully via an amide bond. DSC and XRD results showed that the thermal stability of CS had been significantly improved by grafting PLLA to the molecular chains of CS and the crystallinity of the CS- g -PLLA copolymers decreased significantly. Elemental analysis showed that the achieved the maximum degree of substitution of PLLA was 60.88%, while the concentration of CS was 2 mg/mL, the PLLA molecular weight was 10,000, and the EDC/NHS ratio was 2:1. Images from SEM demonstrated that the copolymers had a spherical shape and smooth surface. Moreover, the products were well dispersed without any aggregation. POLYM. ENG. SCI., 56:1432–1436, 2016. © 2016 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2016
·Vol. 56
·期 6
·643-649
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IF 1.719
Changlin Cao,Lichao Liu,Qiangpin Li,Pingqin Chen,Qingrong Qian,Qinghua Chen
Wasted polytetrafluoroethylene fibers were recycled using high-energy ball milling technique, and the recylced polytetrafluoroethylene (r-PTFE) was employed to prepare nitrile rubber (NBR)/r-PTFE composites. The structure of r-PTFE and properties of NBR/r-PTFE composites were investigated by polarized optical microscope, laser particle size analyzer, differential scanning calorimetry, and scanning electron microscopy, respectively. The results show that increasing the milling time from 4 to 7 h leads to decreasing the average particle size, the degree of crystallinity and the number-average molecular weight of r-PTFE, whereas no obvious change is found by further prolonging the milling time. It is also clear that the NBR/r-PTFE composite with the r-PTFE obtained from a longer milling time possesses a higher mechanical and solvent resistance property. Compared with pure NBR, NBR/r-PTFE composites with r-PTFE for 7 h milling show a 21.9% increase in modulus at 300% and 27.8% decrease in swelling index. POLYM. ENG. SCI., 56:643–649, 2016. © 2016 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2017
·Vol. 57
·期 12
·1301-1310
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IF 1.449
Xianming Zhang,Menghan Sun,Wenxing Chen
This study examines the selective dispersion of nano-SiO 2 in polystyrene (PS) and polyamide 6 (PA6) blends. With the coupling assistance of 3-methacryloylpropyl trimethoxysilane (MPS), nano-SiO 2 surfaces are grafted with PS chains of different molecular weights (SiO 2 –MPS–PS) or reactive random copolymer of styrene (St) and 3-isopropenyl-α,α′-dimethylbenzene isocyanate (TMI) to produce SiO 2 –MPS–P(St–co–TMI). The isocyanate groups of the reactive copolymer can react with the terminal group of the PA6 to form a graft copolymer, which helps in controlling the location of nano-SiO 2 between the PS and PA6 phases. Field-emission scanning electron microscopy imaging combined with the rheological method was used to investigate the location and dispersion of nano-SiO 2 , as well as the morphology of the PS/PA6 blends, at low nano-SiO 2 loading. Compared with pristine SiO 2 , the modified SiO 2 with different chain lengths adjusted the PA6 phase with refined size and narrow size distribution because of the strong interaction with both phases. The SiO 2 –MPS–PS with appropriate length is the most effective. The use of nano-SiO 2 along with the reactive compatibilizer provides synergistic effects for improving the compatibilization of PS/PA6 blends. POLYM. ENG. SCI., 57:1301–1310, 2017. © 2017 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2017
·Vol. 57
·期 11
·1252-1261
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IF 1.449
Yuan Zong,Hao Tang,Ling Zhao
Poly(p-phenylene terephthalamide) (PPTA) is a typical high-performance fiber and usually synthesized by low temperature solution polycondensation in twin screw extruder. During the reactive extrusion, flow behavior, rheokinetics, and temperature are highly coupled, which makes it difficult to ensure the quality of product. In the present work, the rheokinetics of the PPTA solution is established by experiments and its reactive extrusion is investigated via 3-D numerical simulation. The flow pattern, molecular weight distribution and temperature have been investigated for the extruders with three different elements, i.e., full flight screw (FF), kneading block (KB), and screw mixing element (SME). The results indicate that the unique flow characteristic of different screw elements affects mixing experience of the reactants and further the PPTA qualities. By numerical simulation, it shows the temperature increase within the tested extrusion stage is 7 K and reaction heat is found the main energy source for extrusion stage. Furthermore, heat removal method is verified with consideration of industrial production process. The numerical simulation work also discusses the reaction and mixing process in the extruders with three combined screws. The results show the introduction of more reverse FF and KB elements can lead to higher quality of PPTA. POLYM. ENG. SCI., 57:1252–1261, 2017. © 2017 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2017
·Vol. 58
·期 8
·1381-1390
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IF 1.449
Xianyuan Gu,Ni Li,Jin Cao,Jie Xiong
The polyurethane (PU)/hydrophobic silica gel (HSG) fibrous membranes with the hydrophobic and breathable surface was fabricated via electrospinning. By employing the HSG incorporation, mechanical properties, thermal stability, and waterproofness of the composite membranes could be improved. The porous structure of the membranes would be regulated by tuning the temperatures of thermal treatment. When HSG content increased to 3 wt%, the PU/HSG composite membranes possessed remarkable tensile strength of 6.3 MPa and high water contact angle (WCA) of 134°. Furthermore, the maximum WCA (142° ± 1°), good hydrostatic pressure (5.45 kPa), large water vapor transmission rate (8.05 kg/m 2 /day), and high air permeability (9.25 L/m 2 /s) of the composite membranes could be achieved by heat treatment at 120°C. The resultant membranes performed significantly better when compared to the pure PU membranes under the same conditions, such as the higher tensile strength (100%), better waterproofness (200%), and stronger breathablity (25%). POLYM. ENG. SCI., 58:1381–1390, 2018. © 2017 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2017
·Vol. 58
·期 9
·1523-1529
·
IF 1.449
Yusheng Dong,Jizong Chen,Fredrick Nzioka Mutua,Yuanbo Gao,Tingting Yang,Yong He
To modify the properties of poly(hexamethylene oxamide) (PA62), amine-terminated polyoxypropylene glycols (PGs) were introduced into the polyoxamide main chain as soft segments. A series of PA62/PG2 copolymers were synthesized successfully by a two-step method. Fourier transform infrared spectroscopy, solution proton nuclear magnetic resonance spectroscopy ( 1 H-NMR), differential scanning calorimetry, thermogravimetric analysis, and wide-angle X-ray diffraction were used to analyze the structures and to investigate the properties of these copolymers. The saturated water absorption was also evaluated by gravimetric analysis for PA62/PG2 copolymers. The results revealed the incorporation of PG2 effectively modified the properties of PA62 and the copolymers with PG2 content of 10–20 mol% possessed high melting point (293°C–314°C), good thermal stability and low saturated water absorption. POLYM. ENG. SCI., 58:1523–1529, 2018. © 2017 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2013
·Vol. 54
·期 1
·59-63
·
IF 1.243
Guangren Yu,Qingzeng Li,Na Li,Ziwei Man,Chenghao Pu,Charles Asumana,Xiaochun Chen
A new poly(ionic liquid) of N , N -methylenebisacrylamide (MBA)-crosslinked-poly(4-vinylbenzyltriethylammonium hexafluorophosphate)(MBA-crosslinked-P[VBTEA][PF 6 ]) is prepared through the ion exchange of KPF 6 with the precursor of MBA-crosslinked-P[VBTEA][Cl]; the precursor is synthesized by 4-vinylbenzyltriethylammonium chloride and MBA via inverse suspension polymerization. MBA-crosslinked-P[VBTEA][PF 6 ] is a thermally stable (decomposes at nearly 300°C) and porous (apparent porosity of 64.3% and specific surface of 39.12 m 2 /g) polymer particle with high purity, as indicated by Fourier transformed infrared, energy dispersive spectroscopy, thermogravimetric, scanning electron microscopy, and porous analyses. It is observed that MBA-crosslinked-P[VBTEA][PF 6 ] has good CO 2 adsorption capability of 14.04 mg/g at 0.2 MPa and 25°C, and can be recovered by desorption at vacuum and 80°C, and reused with 99% CO 2 adsorption after four cycles. POLYM. ENG. SCI., 54:59–63, 2014. © 2013 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2014
·Vol. 55
·期 1
·8-13
·
IF 1.441
Tian Lan,Wenjie Yang,Juan Peng,Mingke Li,Yinghan Wang
The article aimed to decrease the memory effect of polymer dispersed liquid crystals (PDLCs) films, reversible additional-fragmental chain transfer (RAFT) polymerization was used to synthesize RAFT-polystyrene (RAFT-PS), which was a kind of RAFT macroinitiators and used to prepare PDLCs via photo polymerization induced phase separation (PIPS). Different RAFT agents were used to synthesize RAFT-PS. The effect of photoinitiator concentration on the memory effect of these PDLCs was investigated, and the effect of structures of RAFT macroinitiators on the memory effect of the PDLCs was also discussed. The results showed that PDLC films with higher photoinitiator concentration and polymer matrix which had two rigid chains in two ends showed lower memory effect, which could be reduced from 10.9% to 2.5% in this experiment. POLYM. ENG. SCI., 55:8–13, 2015. © 2014 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2013
·Vol. 54
·期 11
·2595-2604
·
IF 1.243
Huan Wang,Jingzhao Mo,Baoqing Shentu,Zhixue Weng
The multiepoxy-terminated low-molecular-weight poly (phenylene oxide) (PPOE) was synthesized by modifying the terminal hydroxyl group of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) with epoxy-novolac resin (EPN). The curing kinetics, phase morphology, and thermal stability of the cured EPN/PPOE blends were investigated and compared to the unmodified EPN/PPO and EPN/EPPO (epichlorohydrin-modified PPO) blends. As revealed by the Fourier transform infrared and differential scanning calorimetry analyses, PPOE took part in the curing reaction and formed a crosslinked structure with EPN. The curing rate of EPN/PPOE blends first increased and then decreased with the increase of PPOE fraction. PPOE had both catalytic and steric hindrance effects on the curing reaction. EPN/PPOE blends showed faster curing rate and higher degree of curing than the corresponding EPN/PPO and EPN/EPPO blends. The reactive blending improved the dispersion of PPOE in EPN matrix and the thermal stability of the blend. POLYM. ENG. SCI., 54:2595–2604, 2014. © 2013 Society of Plastics Engineers
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高影响因子
POLYMER ENGINEERING AND SCIENCE
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2014
·Vol. 55
·期 3
·604-613
·
IF 1.441
Yuhong Liu,Xiying Zhang,Ning Gao
In the study, isocyanate-functionalized hyperbranched polyurethane (HPU NCO ) with a degree of branch of 35.2% was synthesized via an A 2 + B 3 method. This novel HPU NCO was used to fabricate a blend system with hydroxyl groups bearing benzoxazine precursor (BZ OH ) to investigate its effective on the thermal properties of BZ OH . The structure of HPU NCO is confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance spectroscopy. The curing behavior of the reactive HPU NCO /BZ OH blend is investigated via differential scanning calorimetry and FTIR analyses. HPU NCO /BZ OH blend indicates two successively broad exotherm peaks centered at 132 and 204°C, respectively, which is obviously different from that of BZ OH with one broad peak centered at 206°C. Thermogravimetric analysis results confirmed that the thermal stability was enhanced and the char yield of BZ OH was increased from 34.3 to 43.2% by cocuring with 10 wt% HPU NCO . POLYM. ENG. SCI., 55:604–613, 2015. © 2014 Society of Plastics Engineers
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高影响因子
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