POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 8
·2245-2252
·
IF 2.137
Lin Tong,Yakai Feng,Xujun Sun,Ying Han,Dongshun Jiao,Xiaohua Tan
The encapsulation of high power light emitting diode (LED) needs the silicone resins to have relative high refractive index and thermal-aging properties. Herein, high refractive index adamantane-based phenyl epoxy-silicone (APES) resins for LED encapsulation were synthesized by the sol-gel condensation of 1-adamantane methanol propyltrimethoxysilane-3-urethane, γ-(2,3-epoxypropoxy)propytrimethoxysilane and diphenylsilanediol. These adamantane-based silicone resins have multifunctional groups including adamantyl group, phenyl group, and epoxy group in order to meet the various requirements for LED encapsulation. Importantly, the adamantane group in the silicone resins benefits for high refractive index and anti-thermal properties. These APES resins were characterized by proton nuclear magnetic resonance and Fourier transform infrared spectroscopy. When APES resins were cured by methylhexahydrophthalic anhydride, they showed relatively high refractive index of 1.56, high hardness, and high thermal resistance. The encapsulated LED demonstrated high adhesion properties by red-ink tests. These merits make adamantane-based silicone resins promising candidates as LED encapsulation materials.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 10
·2665-2673
·
IF 2.137
Xiaodong Guo,Xin Wang,Xiongrui Liu,Yanyang Zheng,Jianzhong Xu,Haiyun Ma
A phosphazene derivative flame retardant with a highly cross-linked microsphere structure, named poly(cyclotriphosphazene-c-sulfonyldiphenol) (PCPS) microspheres, were synthesized by 1-pot reaction and then applied on flame retarded epoxy (EP) resin. The microstructure and chemical composition of PCPS microspheres were characterized using scanning electron microscopy, transmission electron microscopy, and element mapping. The thermal stability of PCPS microspheres and PCPS/EP composites was explored through thermogravimetric analysis. Thermogravimetric data showed that the PCPS microspheres have excellent thermal stability, and the char yield is about 43% at the end of 800°C. The incorporation of PCPS microspheres significantly increased the char yield of PCPS/EP composites. The flammability was investigated by limited oxygen index tests and cone calorimeter. The limited oxygen index value of PCPS/EP composite was increased to 29.8 from 26.6 when 3 wt% of PCPS microspheres was added. Compared with neat EP, the flame retardancy was greatly improved. The peak heat release rate and smoke production rate of PCPS/EP composites were reduced by 45.0% and 43.6%, respectively. The mechanical properties including tensile strength and modulus were both improved due to the enhancement of PCPS microspheres. The PCPS microspheres act as a dual function for improving both the flame resistance and mechanical strength of PCPS/EP system.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 11
·2724-2734
·
IF 2.137
Wei Liu,Xiaolian Zhu,Xinlin Yang,Ke Li,Zupeng Yang
An effective polymerization system was developed for the synthesis of highly cross-linked hydrophilic monodispersed microspheres with both the micropores and mesopores inside. A series of poly( N , N ′-methylenebisacrylamide) (PMBA) microspheres with the diameters ranging from 100 to 300 nm were synthesized by distillation precipitation polymerization with N , N -dimethylacetamide (DMAC) as the porogen, acetonitrile as the solvent, and MBA as the cross-linker and monomer. The particle size, morphology, and porosity varied according to the variation of the DMAC content. The porosity was determined by physical adsorption of nitrogen, and reached the maximum at 7.5 vol% of DMAC with the specific surface area at 135.8 m 2 g −1 and the total pore volume at 0.43 cm 3 g −1 . The porous and hydrophilic microspheres showed excellent swelling property in water and adsorption property for the Cd(II) in aqueous solution. Meanwhile, carboxylic groups were incorporated into the porous microspheres to achieve porous poly( N , N ′-methylenebisacrylamide- co -acrylic acid) (P (MBA- co -AA)-P), which exhibited obvious synergies of the pores and functional groups on the adsorption and provided a perspective application of the Cd(II) removal.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 10
·2574-2582
·
IF 2.137
Xi Chen,Jun Wang,Siqi Huo,Shuang Yang,Bin Zhang,Haopeng Cai
Ternary flame-retardant modified cyanate ester blends (CEPG and CEPA) are formed by combining triazine compounds (TGIC or TAIC) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide with cyanate ester resin. The curing behaviors, thermal and mechanical properties, and the flame-retardant properties are investigated. The results show that the CEPG and CEPA blends result in lower curing temperatures and glass transition temperatures than those of neat CE. Both of CEPG and CEPA blends significantly improve the flame-retardant properties of CE resins, and UL-94V-0 rate is achieved for CEPG-1.0 and CEPA-0.5. The dielectric constant and loss of CEPA blends are lower than those of CEPG blend with the same phosphors content, and both of them are lower than those of neat CE. Therefore, the ternary flame-retardant modified cyanate ester blends provide 2 ways for composites of producing printed circuit board with high flame-retardant property and low dielectric constant and loss.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 9
·2545-2552
·
IF 2.137
Wei Cai,Xiaowei Mu,Ying Pan,Wenwen Guo,Junling Wang,Bihe Yuan,Xiaming Feng,Qilong Tai,Yuan Hu
Although hexagonal boron nitride (h-BN) has presented a potential prospect in polymer composite fields, undesirable interfacial interaction with polymer matrix that generates serious aggregation of nanomaterials has suppressed its enhancement effect. Moreover, the chemically inert surface of h-BN also makes the commonly used approach that improves the interfacial interaction between nanofillers and polymeric matrix invalid. Herein, the functionalized modification of chemically inert h-BN was successfully fabricated by the adsorption of cetyl-trimethylammonium bromide, with electrostatic interactions. The obtained h-BN (cetyl-trimethylammonium bromide-BN) was well characterized by systematic tests and then added into thermoplastic polyurethane (TPU) matrix. The inclusion of functionalized h-BN can dramatically improve thermal stability, flame retardant, and mechanical properties of TPU composites. With the incorporation of as low as 4.0 wt% nanofillers, maximal value of heat release rate and total heat release of TPU were reduced by 57.5% and 17.8%, compared with those of pure TPU, respectively. Moreover, tensile strength of TPU composite with a loading of 2.0 wt% was increased by 79.3% in comparison with that of neat TPU. The facile functionalized approach of chemically inert h-BN paves the way for promising applications of h-BN in the development of flame retardant polymer materials.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 12
·3142-3150
·
IF 2.137
Si Chen,Shichao Lin,Yan Hu,Meng Ma,Yanqin Shi,Junding Liu,Feng Zhu,Xu Wang
The fast biodegradation rate and inflammability of polybutylene succinate (PBS) severely restrict its applications in many areas. To solve the above problems and broaden its applications, herein, a halogen-free flame retardant (CP-lignin) based on lignin was successfully synthesized. After adding 30 wt% CP-lignin into PBS, the peak heat release rate and total heat release of PBS are remarkably reduced by 27 and 31%, respectively. Additionally, the higher char yield was beneficial to improving the flame retardant properties of PBS. After adding 10 wt% CP-lignin, the ratio of weight loss is reduced by about 33%, and the ratio of weight loss is decreased gradually as the CP-lignin loading increases. This research provides a reasonably way to make full use of the lignin and to broaden the application of PBS. At the same time, it also provides a new idea for the production and preparation of completely biodegradable materials.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 7
·1922-1929
·
IF 2.137
Yuanyuan Song,Lishuai Zong,Feng Bao,Guiyang Li,Zuoqiang Wu,Nan Li,Jinyan Wang,Xigao Jian
The effects of inorganic particles such as Al 2 O 3 and B 4 C on the solidification kinetics and heat resistance of phthalonitrile resin were investigated. The properties of the blends and the cured products were tested by rheometer, differential scanning calorimetry, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The results revealed that B 4 C and Al 2 O 3 inorganic particles could prolong the gel time of phthalonitrile resin and broaden the processing window. The curing kinetic analysis showed that the presence of the particles could significantly reduce the curing activation energy of phthalonitrile resins by 72.38 kJ/mol down to 43.03 kJ/mol. Meanwhile, the heat resistance of the phthalonitrile resin was improved. Among them, the blend system combined with 30% B 4 C showed prominent thermoresistance. And while the T d5% weight loss temperature was 600°C, char yield at 1000°C was higher than 86% under nitrogen atmosphere; while the T d5% weight loss temperature was 581°C, char yield at 1000°C was higher than 80% under air atmosphere. Hence, the resulting resins were good candidate matrix of high-temperature structural composites.
✓ 已验证
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 7
·2147-2160
·
IF 2.137
Ping Zhu,Zhongji Gu,Shu Hong,Hailan Lian
Layered double hydroxides (LDHs) are emerging as a new and green high-efficient flame retardant. But LDHs aggregate seriously because of their hydrophilicity, which affect deeply the mechanical and flame retardant properties of their composites. For the first time in this paper, microencapsulated LDHs (MCLDHs) with melamine-formaldehyde (MF) resin were prepared by microencapsulation technology to enhance their compatibility and dispersion within epoxy resin (EP). The mechanical and flame retardant performances of EP/MCLDH composite were studied by comparing with EP/LDH composite. Results showed that the water contact angle of MCLDHs increased from 8.9° to 122.1°, which indicated good compatibility. The particle size of MCLDHs decreased sharply, and more than one-third were up to submicron scale, which can be conducive to dispersion. Moreover, the tensile strength and elongation at break of EP/MCLDHs with different flame retardant contents were higher than those of EP/LDHs. And the addition of MCLDHs increased the glass transition temperature (Tg) of EP/MCLDHs, which meant a strong interfacial interaction. Besides, compared with EP/LDHs, the limiting oxygen index values of EP/MCLDHs were higher, and its peak of heat release rate and total heat release decreased by 16.3% and 5.5% respectively. EP/MCLDHs achieved from V-1 to V-0 rate with the increasing content of MCLDHs from 20% to 30%, while LDHs/EP never passed tests. In the process of heating, H 2 O, CO 2 , and NH 3 released from MCLDHs formed gaseous phase, and the remaining dense char layers and oxides produced condensed phase, which played an important role in inhibiting combustion.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 30
·期 1
·40-50
·
IF 2.137
Feng Su,Xiangke Sun,Rongye Li,Yuandou Wang,Laishun Xi,Yangsheng Chen,Suming Li
A series of poly(ɛ-caprolactone/glycolide)-poly(ethylene glycol) (P(CL/GA)-PEG) diblock copolymers were prepared by ring opening polymerization of a mixture of ɛ-caprolactone and glycolide using mPEG as macro-initiator and stannous octoate as catalyst. Self-assembled micelles were prepared from the copolymers using nanoprecipitation method. The micelles were spherical in shape. The micelle size was larger for copolymers with longer PEG blocks. In contrast, the critical micelle concentration of copolymers increased with decreasing the overall hydrophobic block length. Drug loading and drug release studies were performed under in vitro conditions, using paclitaxel as a hydrophobic model drug. Higher drug loading was obtained for micelles with longer poly(ε-caprolactone) blocks. Faster drug release was obtained for micelles of mPEG2000 initiated copolymers than those of mPEG5000 initiated ones. Higher GA content in the copolymers led to faster drug release. Moreover, drug release rate was enhanced in the presence of lipase from Pseudomonas sp., indicating that drug release is facilitated by copolymer degradation. The biocompatibility of copolymers was evaluated from hemolysis, dynamic clotting time, and plasma recalcification time tests, as well as MTT assay and agar diffusion test. Data showed that copolymer micelles present outstanding hemocompatibility and cytocompatibility, thus suggesting that P(CL/GA)-PEG micelles are promising for prolonged release of hydrophobic drugs.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 12
·3159-3170
·
IF 2.137
Kai Huang,Xiao Quan,Xipeng Li,F. Handan Tezel,Baoan Li
Organic fouling has been a major impediment for the widespread application of nanofiltration membranes because it could degrade the performance and shorten the service life of such membranes. In this study, the NH 2 -functionalized silica nanoparticles (NH 2 –SiO 2 NPs) were grafted on the surface of commercial NF90 membrane to improve the hydrophilicity and antifouling property with the N -(3-dimethylaminopropyl)- N -ethylcarbodiimide hydrochloride coupled with the N -hydroxysuccinimide (EDC/NHS) to activate carboxyl groups on the membrane surface. The surface roughness (Ra) of this modified membrane decreased from value of 47.4 nm of the pristine membrane to 43 nm. The water contact angle of the modified membrane decreased from 48.4° to 15°, indicating the high hydrophilicity of the surface. Moreover, the EDC/NHS membrane showed good stability when it was exposed to the ruinous physical stress (2-min sonication). The optimized grafting conditions, including the SiO 2 concentration (0.5 wt%), the activation time of EDC/NHS (20 min), and the reaction time of NH 2 –SiO 2 NPs with membrane surface (12 h), were obtained by a series of experiments. Under the antifouling test of 36 hours with bovine serum albumin (BSA) and hexadecyltrimethylammonium bromide (CTAB) as foulants, the EDC/NHS membrane lost 42.1% and 49.6% of its initial flux, respectively, which is lower than that of the pristine membrane (52.2% and 68%, respectively). After cleaning with deionized water for 2 hours, the EDC/NHS membrane also showed significant improvement of flux recovery ratio (92% and 87%, respectively) than did the pristine membrane (70.3% and 60%, respectively).
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 11
·2797-2805
·
IF 2.137
Hanyuan Li,Wei Wang,Guofei Chen,Xiaoqi Chen,Yantao Li,Haijun Zhou,Xingzhong Fang
Novel highly soluble phenylethynyl-endcapped oligoimides with different calculated molecular weights were prepared by using mellophanic dianhydride and bis(4-amino-2-trifluoromethylphenyl)ether in the presence of 4-phenylethynyl phthalic anhydride as the reactive endcapping agent. The effect of molecular weights of the aromatic oligoimides on their solubility and processability as well as the thermal and mechanical properties of the thermal-cured polyimides was fully investigated. This kind of phenylethynyl-terminated imides exhibited excellent comprehensive properties. Most importantly, a big progress has been made in the solubility of the oligoimides in this paper. Most of the oligoimides showed excellent solubility (more than 33 wt%) even in acetone , which was reported for the first time. And oligoimides with appropriate molecular weights also showed very good processability with minimum melt viscosities no higher than 120 Pa·s by the rheological study. After thermally curing at 370°C for 1 hour, the cured flexible films showed very high glass transition temperatures up to 392°C by dynamic mechanical analysis, and the temperature of 5% weight loss was higher than 500°C in both air and N 2 atmosphere by thermogravimetric analysis. The cured films also exhibited very good toughness with elongation up to 9%.
✓ 已验证
产品关联
DOI
高影响因子
POLYMERS FOR ADVANCED TECHNOLOGIES
·
2018
·Vol. 29
·期 10
·2674-2682
·
IF 2.137
Yanping Wu,Jia Dong,Rui Yuan,Hongqi Wan,Lei Chen,Jinlong Li,Huidi Zhou,Jianmin Chen
Solution styrene butadiene and butadiene rubber (SSBR-BR) composites reinforced with different contents of SiO 2 -graphene have been fabricated firstly. The mechanical properties of the rubber composites were comparatively investigated using tensile tests; experimental results showed that, as an overall trend, the tensile and tear strength increased with increasing contents of SiO 2 -graphene. Most importantly, under the condition of simulating practical working condition, the tribological behavior of SSBR-BR composites with different contents of SiO 2 -graphene was explored via a universal ring-plate frictional tester in detail. Combined with the surface roughness of the counterparts, the wear mechanisms were discussed for SSBR-BR composites under the cement and asphalt counterparts. Finally, several wear mechanisms under different actual working conditions were proposed.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）