scholarly journals Synergistic effects of zwitterionic segments and a silane coupling agent on zwitterionic shape memory polyurethanes

RSC Advances ◽  
2017 ◽  
Vol 7 (67) ◽  
pp. 42320-42328 ◽  
Author(s):  
Zaochuan Ge ◽  
Huanhuan Ren ◽  
Shuqin Fu ◽  
Shaojun Chen

A novel strategy to improve shape memory properties of ZSMPUs by using a silane coupling agent. The synergistic effects of zwitterionic segments and silane coupling agents on the structure, morphology, properties were carefully investigated.

2018 ◽  
Vol 922 ◽  
pp. 20-25 ◽  
Author(s):  
Hee Seon Lee ◽  
Jeong Min Park ◽  
Kyu Hong Hwang ◽  
Hyung Mi Lim

Highly crystalline and dispersible zirconia, synthesized by solvothermal reaction of zirconium (IV) isopropoxide isopropanol complex in benzyl alcohol, were functionalized with silane coupling agent and dispersed with o-phenylphenoxyethyl acrylate (OPPEA). Silane coupling agents such as 3-aminopropyltriethoxysilane (APTES) of amino functional silane, decyltrimethoxysilane (DTMS) of alkyl functional silane and 3-(trimethoxysilyl) propyl methacrylate (MPS) of acrylate functional silane have been used to modify nanoparticle surfaces and obtain dispersion of nanoparticles within OPPEA. The surface modified zirconia was compared according to silane coupling agent, FT-IR and TGA demonstrated that APTES, DMTS and MPS are chemically attached to the surface of the zirconia. The MPS-zirconia is dispersed as about 5 nm sized, whereas the APTES-zirconia, DTMS-zirconia are agglomerated. The MPS-zirconia/tetrahydrofuran (THF) sol at 15wt% loading shows high transmittance of 68 % at 550 cm-1 and the 50wt% surface modified-zirconia/OPPEA sol show refractive index of 1.657.


Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4896
Author(s):  
Yiren Pan ◽  
Meng Zhang ◽  
Jian Zhang ◽  
Xiaoyao Zhu ◽  
Huiguang Bian ◽  
...  

In this paper, the areca fiber was extracted by physical and chemical treatment, and then the areca fiber/natural latex composite was prepared by natural latex impregnation technology. In order to combine areca fiber and natural rubber latex better, three silane coupling agents with different action mechanism were selected: Si−69, KH550, and KH570 which were used to treat the areca fiber/natural latex compound. The results show that the silane coupling agent can change the surface of the fiber from hydrophilic surface to organophilic surface, making the bonding of areca fiber to natural latex more closely. At the same time, the mechanical properties, physical and mechanical properties, swelling properties, and dynamic viscoelastic properties of the tightly bonded areca fiber/nature latex composites were improved. After observing the micro-structure through a scanning electron microscope, it was found that the three silane coupling agents could effectively bind areca fiber and natural latex to enhance the performance of the composite material, of which Si−69 performed best, and the tensile strength and tear strength of the composite increased by 21.19% and 12.90% respectively.


2021 ◽  
Vol 2 (2) ◽  
pp. 1-7
Author(s):  
Andrei-Ionut Perdum

In this study will be presented, how 20 millilitres of Silane Coupling Agent, adhered on 5 grams of Hollow Glass Bubbles (HGB), how the micro bubbles are looking before and after mixing, how to filter the hollow spheres from the agent and what needed to be taken in consideration when using coupling agents in processes. This paper will show how Silane Coupling Agent (3-Aminopropyl) triethoxysilane, adhered on the Hollow Glass Bubble (HGB). It is expected to observe at HR-SEM (High- Resolution Scanning Electron Microscopy) how the Hollow Glass Bubbles looks when the Silane Coupling Agent (KH-550) is applied on the filler vs when is not. During the process will be concluded, what risks should be taken in consideration, when using Silane Coupling Agents on Hollow Glass Spheres and what important information/ steps are needed to be taken in consideration before and after coupling treatment.


Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3058
Author(s):  
Sang Yoon Lee ◽  
Jung Soo Kim ◽  
Seung Ho Lim ◽  
Seong Hyun Jang ◽  
Dong Hyun Kim ◽  
...  

The methoxy-type silane coupling agents were synthesized via the modification of the hydrolyzable group and characterized to investigate the change in properties of silica/rubber composites based on the different silane coupling agent structures and the masterbatch fabrication methods. The prepared methoxy-type silane coupling agents exhibited higher reactivity towards hydrolysis compared to the conventional ethoxy-type one which led to the superior silanization to the silica filler surface modified for the reinforcement of styrene-butadiene rubber. The silica/rubber composites based on these methoxy-type silane coupling agents had the characteristics of more developed vulcanization and mechanical properties when fabricated as masterbatch products for tread materials of automobile tire surfaces. In particular, the dimethoxy-type silane coupling agent showed more enhanced rubber composite properties than the trimethoxy-type one, and the environmentally friendly wet masterbatch fabrication process was successfully optimized. The reactivity of the synthesized silane coupling agents toward hydrolysis was investigated by FITR spectroscopic analysis, and the mechanical properties of the prepared silica-reinforced rubber polymers were characterized using a moving die rheometer and a universal testing machine.


2011 ◽  
Vol 71-78 ◽  
pp. 3687-3690
Author(s):  
Shu Lian Chen ◽  
Hua Yan ◽  
Jian Zhang

This paper mainly deals with the preparation and performance of microencapsulated paraffin insulation mortar. Silane coupling agents are used to modify the surface of the microencapsulated paraffin, and fibers are introduced to solve the cracking of microencapsulated paraffin insulation mortar. Research has been carried out on the effect of the type and dosage of silane coupling agents and fibers on the performance of insulation mortar, the result of which shows that KH550 and polypropylene fiber are of good performance and that their optimum dosages are 13% and 0.3% respectively, the dosage was referred to as the percentage according to the weight of cement.


2020 ◽  
Vol 12 (4) ◽  
pp. 594-599
Author(s):  
Choong-Jae Lee ◽  
Bum-Geun Park ◽  
Kwang-Ho Jung ◽  
Yongil Kim ◽  
Seung-Boo Jung

It is difficult to maintain high adhesion strength between a printed metal circuit and polymer substrate due to the weak chemical bonding of metal and organic materials. Therefore, an additional process is necessary to improve the adhesion strength. Silane coupling agents (SCAs), which are capable of forming bonds with metals and organic materials, can provide a solution. Here, SCAs were placed on polyimide (PI) substrates and coated with various functional groups to compare the effects of various functionalized SCAs on the adhesion strength between a screen-printed copper (Cu) circuit and the PI substrate, where the printed Cu patterns were fabricated on the coated PI substrate. Chemical bonding between the coated silane coupling agent and the PI substrate interface was investigated by X-ray photoelectron spectroscopy. The adhesion strength of the screen-printed Cu circuit and PI substrate interface was measured by a roll-type 90° peel test. The surface free energy was calculated using the contact angle. The failure mode was analyzed by field emission scanning electron microscopy. The silane coupling agent containing an amine functional group significantly improved the adhesion strength because it facilitates a superior bond between organic substrates and metals via chemical reactions such as copolymerization and graft copolymerization. As a result, the adhesion strength between the printed Cu pattern and PI increased about 4.26 times with the use of SCAs.


2012 ◽  
Vol 23 (1) ◽  
pp. 08-14 ◽  
Author(s):  
Veridiana Resende Novais ◽  
Paulo Cézar Simamotos Júnior ◽  
Regina Maria Puppin Rontani ◽  
Lourenço Correr-Sobrinho ◽  
Carlos José Soares

This study evaluated the effect of air drying temperature and different silane coupling agents on the bond strength between glass fiber posts and composite resin core. The post surface was cleaned with alcohol and treated with different silane coupling agents, being three prehydrolyzed silanes [Silano (Angelus), Prosil (FGM), RelyX Ceramic Primer (3M ESPE)] and one two-component silane [Silane Coupling Agent (Dentsply)]. Two post-silanization air drying temperatures, 23ºC and 60ºC, were applied. A cylindrical plastic matrix was placed around the silanized post and filled with composite resin. Each bonded post provided 7 slices for push-out testing. Each slice was loaded to failure under compression at a cross-head speed of 0.5 mm/min. Data were analyzed by two-way ANOVA and Scott-Knott tests (α=0.05). Dunnett's test was used to compare the mean of the control group with that of each experimental group. Scanning electron microscopy (SEM) was used to evaluate the interface of the fractured slices. For the 23ºC air drying temperature, the use of RelyX Ceramic Primer resulted in significantly lower bond strength than the other silane coupling agents, while the bond strength with Silane Coupling Agent was the highest of all groups. Only with Silane Coupling Agent, the bond strength for the 23ºC air drying temperature was significantly higher than that for 60ºC air drying. In conclusion, the use of warm air drying after silane application produced no increase in the bond strength between the fiber-reinforced composite post and the composite core. The two-component silane produced higher bond strength than all prehydrolyzed silanes when it was used with air drying at room temperature.


2014 ◽  
Vol 87 (2) ◽  
pp. 291-310 ◽  
Author(s):  
W. Kaewsakul ◽  
K. Sahakaro ◽  
W. K. Dierkes ◽  
J. W. M. Noordermeer

ABSTRACT Polar functionality attached onto natural rubber has a significant impact on the reinforcing efficiency of silica. Parallel studies involving various levels of epoxidation on natural rubber (ENR) in the absence of bis-(triethoxysilylpropyl) tetrasulfide (TESPT) coupling agent, as well as a combination of ENRs with different loadings of TESPT, provide a better understanding of the various factors that influence the properties of silica-filled ENR compounds. Based on the overall properties, the best possible combination to optimize processability, to reduce filler–filler interaction, and improve vulcanization rate as well as vulcanizate properties, is to use ENR with an epoxide content in the range of 20–30 mol%, together with a small portion of TESPT, that is, 2–4 wt% relative to the silica content. This leads to a reduction of approximately 60–80% of TESPT when compared with the conventional NR compounds, where the optimal loading of TESPT was 9.0 wt% relative to the silica content.


2022 ◽  
Author(s):  
Jialong Yu ◽  
Weiyu Wang ◽  
Shumin Li ◽  
Beibei Yu ◽  
Hongyu Chen ◽  
...  

Seaweed-like Au nanowires were synthesized without any nanoparticle seeds. The amino silcane coupling agent 3-aminopropyltriethoxysilane was used to form the active surface on Au substrate to facilitate one dimensional growth....


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