-----------------

JW Latex Consultants (and Rubber Consultants,乳胶顾问) offer solutions to your problems in Natural Rubber latex and Synthetic Rubber latex processing and the manufacturing of latex products (condoms, catheters, medical gloves, baby teats and soothers, toy balloons etc) Quick answers through e-mails are possible at reasonable cost.

You Are Visitor Number:

counter
Expedia Promotional Codes

__________________________

This Site Is Best Viewed With Mozilla Firefox Browser. If You Are Viewing With Internet Explorer, It Is Advisable to Switch to Mozilla Firefox By Going to This Link -> http://www.mozilla.org/en-US/firefox/new/

It Is Free to Download

__________________________

Send Your Enquiry and Orders To: woonsungliang@yahoo.com.sg

Problem Solving Through E-Mails with John Woon Latex Consultants Is Possible
可以通过电子邮件与JW乳胶顾问来解决问题

__________________________

Please kindly donate to support the maintenance of this site. We'd appreciate it very much.

__________________________

__________________________________________________________________________

Tuesday, August 14, 2012

How Does Prevulcanisation Inhibitor Works?

Manufacturer: We are manufacturing rubber mouldings using SMR rubber. We often encounter scorch problems of our rubber compounds due to uncontrolled curing rate even when we use sulphenamide. Our associate had recommended that we should try to use "Prevulcanisation Inhibitor'. How can this help us?

John Woon (Senior Latex Consultant):  The best way to control the vulcanization behaviour of the rubber is through careful choice of curatives and accelerator. Very often, for a more "plateau" and less scorchy cure, one normally uses sulphenamides while for intermediate scorch delay, MBT, MBTS or a blend of both are used.

In order to improve productivity, secondary accelerators such as thiurams and DPG are added to reduce the cure time. However this is achieved at the expense of optimal cure state and the final physical properties.

To prevent this problem, one could use "Prevulcanization Inhibitor" i.e. you can achieve the scorch safety you want without affecting the physical properties.

Here is how it works:

1) Sulphenamide reacts with sulphur forming a complex polysulphide
2) Polysulphide in turn reacts further with rubber, liberating MBT and forming rubber-polysulphides
3) MBT released act as a catalyst for the formation of intermediate polysulphides
3) Rubber-polysulphides then inter-react resulting in vulcanized rubber

Prevulcaniszation Inhibitor (PI) mops up MBT by reacting stoichiometrically with it. Hence vulcanization is delayed until all the PI has been consumed.

I suggest you experiment with different levels (e.g. 0.1 to 0.4 phr) of PI. One good example of PI is Cyclohexylthio-phthalimide.
Molecular Structure of 17796-82-6 (1H-Isoindole-1,3(2H)-dione,2-(cyclohexylthio)-)





0 Comments:

Post a Comment

<< Home

__________________________

What has the bouncing ball to do with tyres?

Latex Gloves Educational Articles from the Malaysian Rubber Export Promotion Council

How do you select your medical gloves?

Rubber Chemicals: Carcinogenicity, Mutagenicity, Clastogenicity.

Why is Compression Set measurement important?

Assessment of Latex Stability

Joule Effect

Poor Flocking Quality Of Household Gloves

Creaming of Latex

What is Vulcanization?

History of Latex Dipped Products

Applications of Prevulcanized Latex

Defoamer Creating Havoc in Glove Factory

Problems With Milling Rubber Chemicals

Medical Gloves From Guayule Latex

Introduction to SMG Gloves

 

 

Click on The Following Links to Read More Articles:

[Advantages of Vulcanization] [Applications of PV Latex] [Bacteria and Latex] [Chemical Toxicity] [Cross-Linking Density] [Biodegradability] [Black Articles] [Blooming] [Bouncing Ball] [Compression Set] [Condoms] [Creaming] [Defoamer] [FDA] [Fatty Acid Soaps] [Flame Retardant] [Flocking] [Food Packaging] [Glove Demand] [Glove Selection] [Guayule Latex] [History of Gloves] [Joul Effect] [Latex Stability] [Latex Thread] [Milling Problem] [MREPC Articles] [Nano Polymer Particles] [Nano ZnO] [Polychloroprene] [REACH] [SMG] [Storage Hardening] [Vulcanization] [Vytex] [Yulex]

Disclaimer:
The information and data contained in this site are believed to be accurate and reliable. However it is the responsibility of the visitors and readers to satisfy themselves that the information is workable under their own processing conditions. Hence the owners of this site make no warranties concerning the suitability of the information given in this site.

__________________________