scholarly journals Enhancing Toughness and Impact Strength of Epoxy Resins by Using Hyperbranched Polymers

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Hangyu Park ◽  
Youngson Choe

Toughened epoxy has been widely used in industrial areas such as automotive and electronics. In this study, nanosized hyperbranched polymers (HBPs) as a flexibilizer are synthesized and embedded into epoxy resin to enhance the toughness and flexibility. Two different HBPs, hyperbranched poly(methylacrylate-diethanolamine) (poly(MA-DEA)) and poly(methylacrylate- ethanolamine) (poly(MA-EA)), were prepared and blended with both epoxy and polyetheramine, a curing agent. The molecular size of HBPs was estimated to be 6 ~ 14 nm in diameter. The molecular weight of HBPs ranges from 1500(1.5 K) to 7000(7.0 K) g/mol. In cured epoxy/HBP blends, no phase separations are occurred, indicating that HBPs possess sufficient miscibility with epoxy. The tensile toughness of the blends increased with changing the molecular weight of HBPs without sacrificing tensile strengths. The impact strength of the blends increases stiffly until the loading % of HBPs in the blends reaches 10 wt%. In addition, the experimental studies showed that impact resistance also increased with an increase in molecular weight of HBPs. The obtained impact resistance of the epoxy/HBP blends with 10 wt% was 270% more effective compared to that of cured neat epoxy.

Nanomaterials ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2452
Author(s):  
Nirmal Marasini ◽  
Changkui Fu ◽  
Nicholas L. Fletcher ◽  
Christopher Subasic ◽  
Gerald Er ◽  
...  

A better understanding of the impact of molecular size and linkers is important for PEG-based hyperbranched polymers (HBPs) intended as tailored drug delivery vehicles. This study aimed to evaluate the effects of crosslinker chemistry (cleavable disulphide versus non-cleavable ethylene glycol methacrylate (EGDMA) linkers) and molecular weight within the expected size range for efficient renal elimination (22 vs. 48 kDa) on the intravenous pharmacokinetic and biodistribution properties of 89Zr-labelled HBPs in rats. All HBPs showed similar plasma pharmacokinetics over 72 h, despite differences in linker chemistry and size. A larger proportion of HBP with the cleavable linker was eliminated via the urine and faeces compared to a similar-sized HBP with the non-cleavable linker, while size had no impact on the proportion of the dose excreted. The higher molecular weight HBPs accumulated in organs of the mononuclear phagocyte system (liver and spleen) more avidly than the smaller HBP. These results suggest that HBPs within the 22 to 48 kDa size range show no differences in plasma pharmacokinetics, but distinct patterns of organ biodistribution and elimination are evident.


2015 ◽  
Vol 294 (3) ◽  
pp. 607-615 ◽  
Author(s):  
Shuiping Li ◽  
Huajun Zhu ◽  
Tingting Lv ◽  
Qin Lin ◽  
Haijun Hou ◽  
...  

2013 ◽  
Vol 850-851 ◽  
pp. 70-73
Author(s):  
Hua Wang ◽  
Hao Dong Song ◽  
En Guang Zou ◽  
Teng Jie Ge ◽  
Hong Fang

The performance of JHMGC100S, a kind of HDPE for pipe, was studied, and the comparison with other typical PE100 resin in China and abroad was also did. The results show that: the impact strength of JHMGC100S was higher than other samples, and the bending strength was almost the same; the molecular weight distribution was obvious bimodal; the processability of JHMGC100S was good, and the hydrostatic strength of the pipe which was produced by JHMGC100S fulfilled the rule in GB/T 15558.1-2003.


2020 ◽  
Vol 15 ◽  
pp. 155892502090132
Author(s):  
Sang-Hoon Lee ◽  
Seung-Won Oh ◽  
Young-Hee Lee ◽  
Il-Jin Kim ◽  
Dong-Jin Lee ◽  
...  

To prepare flame-retardant epoxy resin, phosphorus compound containing di-hydroxyl group (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phospha phenanthrene-10-oxide, DOPO-HQ) was reacted with uncured epoxy resin (diglycidyl ether of bisphenol A, YD-128) and then cured using a curing agent (dicyandiamide, DICY). This study focused on the effect of phosphorus compound/phosphorus content on physical properties and flame retardancy of cured epoxy resin. The thermal decomposition temperature of the cured epoxy resins (samples: P0, P1.5, P2.0, and P2.5, the number represents the wt% of phosphorus) increased with increasing the content of phosphorus compound/phosphorus (0/0, 19.8/1.5, 27.8/2.0, and 36.8/2.5 wt%) based on epoxy resin. The impact strength of the cured epoxy resin increased significantly with increasing phosphorus compound content. As the phosphorus compound/phosphorus content increased from 0/0 to 36.8/2.5 wt%, the glass transition temperature (the peak temperature of loss modulus curve) increased from 135.2°C to 142.0°C. In addition, as the content of phosphorous compound increased, the storage modulus remained almost constant up to higher temperature. The limiting oxygen index value of cured epoxy resin increased from 21.1% to 30.0% with increasing phosphorus compound/phosphorus content from 0/0 to 36.8/2.5 wt%. The UL 94 V test result showed that no rating for phosphorus compounds less than 19.8 wt% and V-1 for 27.8 wt%. However, when the phosphorus compound was 36.8 wt%, the V-0 level indicating complete flame retardancy was obtained. In conclusion, the incorporation of phosphorus compounds into the epoxy chain resulted in improved properties such as impact strength and heat resistance, as well as a significant increase in flame retardancy.


2013 ◽  
Vol 49 (6) ◽  
pp. 1610-1620 ◽  
Author(s):  
Marjorie Flores ◽  
Mireia Morell ◽  
Xavier Fernández-Francos ◽  
Francesc Ferrando ◽  
Xavier Ramis ◽  
...  

2017 ◽  
Vol 17 (01) ◽  
pp. 1750019
Author(s):  
MARYAM KALANTARI ◽  
ATA HASHEMI

Antibiotic-impregnated poly(methyl methacrylate) (PMMA) bone cement has been successfully used to treat infected joint arthroplasties and surgeons have advocated the use of antibiotic-treated bone cement to prevent possible infections in joint replacement surgeries. However, there is a concern that this addition may adversely affect the mechanical properties of the bone cement. In most cases, the addition of antibiotics to bone cement has been reported to lower its mechanical strength. The uniaxial, biaxial and three/four point bending tests of antibiotic-impregnated bone cement have been extensively performed and well documented. However, only a few documents have focused on the impact strength of bone cement. The present study reports the impact tests of control and antibiotic loaded bone cements at different temperatures and aging conditions. According to the results, the addition of gentamicin or vancomycin significantly reduced the samples' impact strength. Moreover, the samples aged in saline at 23[Formula: see text]C were more resistant than the samples aged in air at 23[Formula: see text]C. Furthermore, raising the storage temperature from 23[Formula: see text]C to 37[Formula: see text]C significantly lowered the bone cement's impact strength in both control and antibiotic loaded samples.


2015 ◽  
Vol 237 ◽  
pp. 154-159
Author(s):  
Szymon Zacharski ◽  
Wojciech Jóźwik

Currently, nearly 1.5 M tons of different types of glassware are produced in Poland, and the majority of it is used as packaging in the food, cosmetic, and pharmaceutical industries. The article presents a method for testing impact resistance of glassware, which was developed at the ITeE-PIB. The authors also present a prototype of a device for glassware tests, discuss a test procedure applied in such tests, and show the results of verification tests for which a high-speed digital camera was used to record the impact strength and the propagation of cracks in glassware. The device in question has been successfully implemented in an industrial research laboratory.


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
M. P. Luda ◽  
V. Brunella ◽  
D. Guaratto

Three used PP-based car bumpers are characterized by many techniques (fractionation, IR, TGA, DSC, DMTA, and SEM). They show different impact and static and dynamic mechanical properties depending on their composition and morphology. It appears that block copolymer compatibilizers constituted by polyethylene-polypropylene sequences allow a better compatibility between the rubber domains and the PP matrix leading to relatively high impact resistance. Indeed if the ethylene sequences of the copolymer are large enough to crystallize, the decreased mobility of the whole system impairs the impact resistance. In addition, a higher amount of rubber in domains regular in shape and of greater dimension (1–3 μm) promotes a more homogeneous dispersion of external force inside the material, decreasing the risk of fracture. The amount of mineral fillers regulates the elastic modulus (the higher the load, the higher the modulus); however, a fairly good interfacial adhesion is required for satisfactory impact strength. All PP-based bumpers have been mechanically recycled in an internal mixer to redistribute oxidized species and to reestablish phase compatibilization. Recycling improves mechanical properties in slow speed test but fails to increase impact strength particularly in filled bumper, in which the quality of the matrix/filler interphase is hard to improve by simple remixing.


Author(s):  
Murat Gökçe ◽  

The paper aims to design a concrete against repetitive impact and abrasion resistance. Macro/micro steel fibers and two types of crushed stone based on limestone and corundum as aggregate were used in concrete mixtures. Impact test device has been modified, designed and used for impact strength testing of concrete. The usability of the plate creep test in determining the impact strength of concrete was also investigated. According to the test results, a high correlation was found between the abrasion, impact resistance tests and the creep test.


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