Plasticization by in Situ Grafted Acrylates II—Effect of Graft Structure

1985 ◽  
Vol 58 (1) ◽  
pp. 146-153
Author(s):  
Roger J. Eldred
Keyword(s):  
Low Temperature ◽  
Chain Transfer ◽  
Direct Result ◽  
Acrylate Monomer ◽  
A Chain ◽  
Low Temperature Flexibility ◽  
Acrylate Monomers ◽  
Better Than ◽  
Transfer Agents

Abstract Grafting of acrylate monomers, such as 2-ethylhexyl acrylate, onto nitrile rubber during the cure cycle leads to improved low temperature flexibility. The effect of graft structure on the improvement was determined by utilizing chain transfer agents to reduce the molecular weight and increase the number of grafts. In every instance, incorporation of a chain transfer agent led to a compound with greater low-temperature flexibility than a control. The amount of improvement was correlated with the effectiveness of each additive in chain transfer reactions. Since there was no evidence of either degradative chain transfer or changes in cure state, it was concluded that the increased low-temperature flexibility was a direct result of alterations in the graft structure. The plasticization achieved with chain transfer agents and 2-ethylhexyl acrylate monomer was better than previously obtained using more effective acrylic monomers without the additives. This means that the structure of the graft is the major factor in determining the effectiveness of in situ grafted acrylate monomers as plasticizers.

Plasticization of Nitrile Elastomers by in Situ Grafted Acrylate Monomers

1984 ◽  
Vol 57 (2) ◽  
pp. 320-327 ◽  
Author(s):  
Roger J. Eldred
Keyword(s):  
Chemical Composition ◽  
Low Temperature ◽  
Side Chain ◽  
Slight Effect ◽  
Cure Cycle ◽  
Simple Addition ◽  
Low Temperature Flexibility ◽  
Acrylate Monomers ◽  
Pure Hydrocarbon

Abstract Grafting of acrylate monomers, such as 2-ethylhexyl acrylate, onto nitrile rubber during the normal cure cycle of the elastomer led to a significant improvement in low-temperature flexibility. This method was shown to provide not only permanent plasticization, but also more than twice the effectiveness obtained by the simple addition of a polymeric acrylic plasticizer. It was found that the improvement in flexibility was directly proportional to the amount of monomer employed. The structure of the monomer was also important in determining its effectiveness, since variations in both the length and chemical composition of the ester side-chain led to changes in the low temperature properties. Improvements were obtained with longer side-chains, while the presence of oxygen in the side chain reduced the effectiveness compared to that of a pure hydrocarbon side-chain. Some slight effect of peroxide type used in the cure system was observed, but no differences in flexibility occurred with variations in cure temperatures between 163° and 204°C.

Rapid-deposited high-performance submicron encapsulation film with in-situ plasma oxidized Al layer inserted

2021 ◽  
Author(s):  
Houyun Qin ◽  
Chang Liu ◽  
Chong Peng ◽  
Mingxin Lu ◽  
Yiming Liu ◽  
...  
Keyword(s):  
Thin Film ◽  
Water Vapor ◽  
Low Temperature ◽  
High Performance ◽  
Transmission Rate ◽  
Visible Region ◽  
Water Vapor Transmission Rate ◽  
Water Vapor Transmission ◽  
Better Than

Abstract High-performance submicron thin-film encapsulation deposited rapidly under low temperature plays an important role in Si-based organic micro-displays. In this letter, the formation mechanism of high-performance encapsulation films consisting of SiO2/in-situ plasma oxidized Al at 77°C is explained. We think that the reason why the performance of encapsulation films deposited by this method behave better than the simple stacking of SiO2/Al2O3 is the formation of Al-O-Si bonds. By further optimizing the process parameters, the water vapor transmission rate and the transmittance in the visible region have been improved, which reached 10-6 g∙m 2∙day 1 and 90%, respectively.

In situ xanthate deprotection to generate thiol chain transfer agents for conventional free radical linear and branched vinyl polymerization

2017 ◽  
Vol 55 (24) ◽  
pp. 3963-3967 ◽  
Author(s):  
Sean Flynn ◽  
Simon D. Dale ◽  
Andrew B. Dwyer ◽  
Pierre Chambon ◽  
Steve P. Rannard
Keyword(s):  
Free Radical ◽  
Chain Transfer ◽  
Vinyl Polymerization ◽  
Transfer Agents

Low Temperature (≥ 400°C) Silicon Pyrometry AT 1.1μm with Emissivity Correction

1995 ◽  
Vol 387 ◽  
Author(s):  
J. C. Sturm ◽  
A. Reddy
Keyword(s):  
Low Temperature ◽  
A Priori ◽  
Silicon Wafers ◽  
A Priori Knowledge ◽  
Single Detector ◽  
Better Than ◽  
Priori Knowledge

AbstractIn this work we have examined the experimental low-temperature limits of 1.1μm pyrometry for the measurement of the temperature of silicon wafers and aluminumcoated silicon wafers at temperatures under 700°C in RTP chambers. In-situ emissivity correction in the same range has also been demonstrated with a single detector for radiation and reflection measurements. Temperatures as low as 450°C have been measured on metallized surfaces with an accuracy of better than 10°C without any a priori knowledge of the wafer emissivity.

scholarly journals Preparation and Properties of Polyester Modified Waterborne High Hydroxyl Content and High Solid Content Polyacrylate Emulsion

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 636 ◽  
Author(s):  
Zhewen Zhu ◽  
Chaoying Zhang ◽  
Shuling Gong
Keyword(s):  
Chain Transfer ◽  
Unsaturated Polyester ◽  
Impact Resistance ◽  
Solid Content ◽  
High Solid Content ◽  
Acrylate Monomer ◽  
Film Properties ◽  
Hydroxyl Content ◽  
Acrylate Emulsion ◽  
Better Than

A high hydroxyl content waterborne polyester-acrylate emulsion was successfully synthesized in two steps. Firstly, the carboxyl terminated unsaturated polyester was synthesized, then it was reacted as a monomer with acrylate monomer by emulsion polymerization using the semi-continuous seeded method. The effects of the amount of hydroxyethyl methacrylate (HEMA), the ratio of polyester/acrylic, the ratio of soft/hard monomer, and the content of chain transfer agent to the properties of the composite emulsion were investigated. Through a variety of tests, both the emulsion and film properties of the composite emulsion were better than polyacrylate emulsion. The introduction of polyester improved the flexibility and impact resistance of hydroxyl acrylate film, and made the modified resin have advantages of both.

A High Angle, Double Tilting Cold Stage for the AEI EM7

1974 ◽  
Vol 32 ◽  
pp. 450-451
Author(s):  
P.R. Swann ◽  
A.E. Lloyd
Keyword(s):  
Habit Plane ◽  
Temperature Control ◽  
Tilt Angle ◽  
Cooling System ◽  
Thermal Drift ◽  
High Angle ◽  
Cold Stage ◽  
High Degree ◽  
Better Than

Figure 1 shows the design of a specimen stage used for the in situ observation of phase transformations in the temperature range between ambient and −160°C. The design has the following features a high degree of specimen stability during tilting linear tilt actuation about two orthogonal axes for accurate control of tilt angle read-out high angle tilt range for stereo work and habit plane determination simple, robust construction temperature control of better than ±0.5°C minimum thermal drift and transmission of vibration from the cooling system.

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