Dynamically Vulcanized PP/EPDM Blends: Multifunctional Peroxides as Crosslinking Agents — Part I

2004 ◽  
Vol 77 (5) ◽  
pp. 955-971 ◽  
Author(s):  
Kinsuk Naskar ◽  
Jacques W. M. Noordermeer
Keyword(s):  
Single Molecule ◽  
Good Alternative ◽  
Thermoplastic Elastomers ◽  
Dicumyl Peroxide ◽  
Thermoplastic Polymer ◽  
Decomposition Products ◽  
Blooming Effect ◽  
Thermoplastic Vulcanizates ◽  
By Products ◽  
Crosslinking Agents

Abstract Thermoplastic vulcanizates (TPVs) or dynamic vulcanizates are a special class of thermoplastic elastomers, produced by mixing and crosslinking of a rubber and a thermoplastic polymer simultaneously. In a previous study, it was demonstrated that the use of dicumyl peroxide in combination with triallyl cyanurate as crosslinking agents provides a good overall balance of physical properties of PP/EPDM TPVs. Commonly used peroxides like dicumyl peroxide generally produce volatile decomposition products, which sometimes provide a typical smell or show a blooming effect. In this paper multifunctional peroxides are described, which reduce the above-mentioned problems. They consist of a peroxide and co-agent-functionality combined in a single molecule. The multifunctional peroxides provide properties of TPVs, which are comparable with commonly employed co-agent assisted peroxides. The solubility and kinetic aspects of the various peroxides are highlighted, as well as the decomposition products of the multifunctional peroxides with respect to the avoidance of smelly by-products. Particularly, 2,4-diallyoxy-6-tert-butylperoxy-1,3,5-triazine turns out to be a very good alternative to the dicumyl peroxide/triallyl cyanurate combination.

Dynamically Vulcanized PP/EPDM Blends: Effects of Different Types of Peroxides on the Properties

2003 ◽  
Vol 76 (4) ◽  
pp. 1001-1018 ◽  
Author(s):  
K. Naskar ◽  
J. W. M. Noordermeer
Keyword(s):  
Mechanical Properties ◽  
Solubility Parameter ◽  
Chemical Nature ◽  
Thermoplastic Elastomers ◽  
Dicumyl Peroxide ◽  
Fragmentation Mechanism ◽  
Blend Ratio ◽  
Thermoplastic Vulcanizates ◽  
Different Types ◽  
Curing Agents

Abstract Thermoplastic vulcanizates (TPVs) or dynamic vulcanizates are thermoplastic elastomers produced by simultaneous mixing and crosslinking of a rubber and a thermoplastic. The effects of different types of peroxides as curing agents on the properties of PP/EPDM TPVs were investigated at a fixed blend ratio. The mechanical properties change significantly with the chemical nature of the peroxides, the extent of crosslinking of EPDM and the extent of degradation of PP. Three main parameters have been identified governing the final mechanical properties of TPVs: the solubility parameter of a peroxide relative to the substrates PP and EPDM, the fragmentation mechanism of the peroxide and the kinetic aspects of the peroxide fragmentation. Dicumyl peroxide gives the best balance of all properties, it complies the best of all with these parameters.

Thermoplastic Elastomers Based on PP/EPDM Blends by Dynamic Vulcanization

2007 ◽  
Vol 80 (3) ◽  
pp. 504-519 ◽  
Author(s):  
Kinsuk Naskar
Keyword(s):  
Thermoplastic Elastomers ◽  
Review Article ◽  
Dynamic Vulcanization ◽  
Phenolic Resins ◽  
Thermoplastic Vulcanizates ◽  
Different Types ◽  
Ethylene Propylene Diene Rubber ◽  
Diene Rubber ◽  
Crosslinking Agents

Abstract This review article introduces various aspects of dynamic vulcanization as applied to thermoplastic elastomers (TPEs). The classification of polymer blends and TPEs, the development of thermoplastic vulcanizates (TPVs), and the application of different types of crosslinking systems with special emphasis on peroxides/co-agents, and phenolic resins as crosslinking agents for polypropylene / ethylene propylene diene rubber (PP/EPDM) blends are primarily reviewed. The morphology and rheology of these TPVs are also touched upon.

Thermoplastic Elastomers by Dynamic Vulcanization

2005 ◽  
Vol 21 (1) ◽  
pp. 1-26 ◽  
Author(s):  
K. Naskar ◽  
J.W.M. Noordermeer
Keyword(s):  
Polymer Blends ◽  
Thermoplastic Elastomers ◽  
Dynamic Vulcanization ◽  
Phenolic Resins ◽  
Thermoplastic Vulcanizates ◽  
End Use ◽  
Crosslinking Agents

The present paper introduces various topics and aspects of dynamic vulcanization as applied to thermoplastic elastomers. The classification of polymer blends and thermoplastic elastomers, the development of thermoplastic vulcanizates, and the use of various types of crosslinking systems (with special emphasis on peroxides/co-agents, and phenolic resins as crosslinking agents for PP/EPDM blends) are reviewed. The morphology and rheology of thermoplastic vulcanizates and their typical end-use applications are also touched upon.

scholarly journals Mono- and Bi-Molecular Adsorption of SF6 Decomposition Products on Pt Doped Graphene: A First-Principles Investigation

2018 ◽  
Vol 8 (10) ◽  
pp. 2010 ◽  
Author(s):  
Yongqian Wu ◽  
Shaojian Song ◽  
Dachang Chen ◽  
Xiaoxing Zhang
Keyword(s):  
Single Molecule ◽  
First Principles ◽  
Density Functional ◽  
Energy Gap ◽  
Adsorption Parameters ◽  
Functional Theory ◽  
Decomposition Products ◽  
Before And After ◽  
Doped Graphene ◽  
Sf6 Decomposition

Based on the first-principles of density functional theory, the SF6 decomposition products including single molecule (SO2F2, SOF2, SO2), double homogenous molecules (2SO2F2, 2SOF2, 2SO2) and double hetero molecules (SO2 and SOF2, SO2 and SO2F2, SOF2 and SO2F2) adsorbed on Pt doped graphene were discussed. The adsorption parameters, electron transfer, electronic properties and energy gap was investigated. The adsorption of SO2, SOF2 and SO2F2 on the surface of Pt-doped graphene was a strong chemisorption process. The intensity of chemical interactions between the molecule and the Pt-graphene for the above three molecules was SO2F2 > SOF2 > SO2. The change of energy gap was also studied and according to the value of energy gap, the conductivity of Pt-graphene before and after adsorbing different gas molecules can be evaluated.

scholarly journals Evaluation of DBPs formation from SMPs exposed to chlorine, chloramine and ozone

2016 ◽  
Vol 15 (2) ◽  
pp. 185-195 ◽  
Author(s):  
Beibei Zhang ◽  
Qiming Xian ◽  
Jian Lu ◽  
Tingting Gong ◽  
Aimin Li ◽  
...  
Keyword(s):  
Natural Organic Matter ◽  
Chlorinated Solvents ◽  
Good Alternative ◽  
Haloacetic Acids ◽  
Soluble Microbial Products ◽  
Key Factors ◽  
Factors Affecting ◽  
Important Group ◽  
Microbial Products ◽  
By Products

Soluble microbial products (SMPs) are an important group of components in wastewater effluents. In this study, the formation of disinfection by-products (DBPs), including trihalomethanes (THMs), haloacetic acids (HAAs), chlorinated solvents (CSs), haloketones (HKs), haloacetonitriles (HANs) and trichloronitromethane (TCNM) (chloropicrin), from SMPs during chlorination, chloramination and ozonation was investigated. More carbonaceous DBPs (C-DBPs: THMs, HAAs, CSs and HKs) and nitrogenous DBPs (N-DBPs: HANs and TCNM) were formed in chlorination than chloramination. More dichloroacetic and N-DBPs, and higher DBP formation potential were generated by SMPs than by natural organic matter. The results also show that disinfection factors, including temperature, pH, disinfectant dose, reaction time and bromide level significantly affected the formation of DBPs from SMPs. Additionally, the bromine incorporation factor indicates that chloramination may be a good alternative to chlorination in reducing the formation of Br-DBPs from SMPs. Bromide level and pH were the key factors affecting the formation of DBPs in both chlorination and chloramination.

Low-K Porous Spin-On-Glass

1999 ◽  
Vol 565 ◽  
Author(s):  
Paul A. Kohl ◽  
Agnes Padovani ◽  
Michael Wedlake ◽  
Dhananjay Bhusari ◽  
Sue Ann ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Elevated Temperatures ◽  
Porous Silica ◽  
Dielectric Materials ◽  
Decomposition Products ◽  
Air Gaps ◽  
Low Dielectric ◽  
Polymer Decomposition ◽  
Low K ◽  
By Products

AbstractPreviously, the fabrication of air-gap structures for electrical interconnections was demonstrated using a sacrificial polymer encapsulated in conventional dielectric materials. The air-gaps were formed by thermally decomposing the sacrificial polymer and allowing the by-products to diffuse through the encapsulating dielectric. The diffusivity of the polymer decomposition products is adequate at elevated temperatures to allow the formation of air-gaps. This process was extended to form low dielectric constant, porous silica from commercially available methylsilsesquioxane (MSQ) by the addition of the sacrificial polymer to the MSQ. The porous MSQ film was thermally cured followed by decomposition of the NB at temperatures above 400°C. The dielectric constant of the MSQ was lowered from 2.7 to 2.3 by creating 70 nm pores in the MSQ. The voids created in the MSQ appeared to exhibit a closed-pore structure.

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