New Polyolefin Elastomers Containing “Reactive” p-Methylstyrene Units: Preparation by Metallocene Catalysts

1999 ◽  
Vol 72 (2) ◽  
pp. 283-298 ◽  
Author(s):  
T. C. Chung ◽  
H. L. Lu ◽  
S. Hong
Keyword(s):  
Molecular Weight ◽  
Metallocene Catalyst ◽  
The Other ◽  
Metallocene Catalysts ◽  
Scanning Calorimetry ◽  
Ethylene Propylene ◽  
Other Hand ◽  
Wide Range ◽  
Natta Catalyst ◽  
Poly Ethylene

Abstract This paper summarizes the experimental results of three new polyolefin elastomers, i.e., poly(1-octene-co- p-methylstyrene (O-p-MS), poly(ethylene-ter-propylene-ter-p-methylstyrene) (EP-p-MS) and poly(ethylene-ter-1-octene-ter-p-methylstyrene) (EO-p-MS), containing “reactive” p-MS units. Both Ziegler-Natta and metallocene catalysts were used in studying co- and ter-polymerization reactions. In the copolymerization of 1-octene and p-MS, Ziegler-Natta catalyst TiCl3/AlEt3 exhibits higher catalyst reactivity to produce high molecular weight O-p-MS copolymers, containing up to 20 mol % p-MS. However, the copolymers show very broad composition and molecular weight distributions. On the other hand, two EP-p-MS and EO-p-MS terpolymers with narrow molecular weight and composition distributions were prepared by [C5Me4(SiMe2NtBu)]TiCl2 metallocene catalyst with constrained ligand geometry. The sharp glass transition temperature (Tg) with flat baseline in each differential scanning calorimetry (DSC) curve indicates homogeneous terpolymer microstructures. The Tg of EP-p-MS is very sensitive to the terpolymer composition (ethylene/propylene ratio and p-MS content). In the compositions with ideal ethylene/propylene ratio ∼ 55/45, the Tα is almost proportional to the content of p-MS. Only with the concentration of p-MS < 2 mol %, does the EP-p-MS show alow Tg<−45°C. On the other hand, the EO-p-MS system exhibits a low Tg<−50°C in a wide range of copolymer compositions, even ones with relatively high p-MS contents (< 7 mol %).

scholarly journals Thermal behavior of PLA plasticized by commercial and cardanol-derived plasticizers and the effect on the mechanical properties

2020 ◽  
Author(s):  
Antonio Greco ◽  
Francesca Ferrari
Keyword(s):  
Mechanical Properties ◽  
The Other ◽  
Poly Lactic Acid ◽  
Poly Ethylene Glycol ◽  
Scanning Calorimetry ◽  
Peg 400 ◽  
Other Hand ◽  
Opposite Behavior ◽  
Poly Ethylene ◽  
Melting And Crystallization

AbstractThis paper is aimed at studying the thermal properties of poly(lactic acid), PLA with different plasticizers. Plasticized PLA was obtained by mixing and extruding PLA with 20 mass% of neat cardanol, epoxidized cardanol acetate (ECA) and poly(ethylene glycol) (PEG) 400. The glass transition of completely amorphous samples, melting and crystallization behavior of plasticized PLA were analyzed by differential scanning calorimetry. Results obtained show that, below Tg, a higher enthalpy relaxation occurs for PLA plasticized by cardanol derivatives. This is indicative of a faster mobility of PLA chains below Tg, when cardanol derivatives are used as plasticizers. On the other hand, an opposite behavior was observed for the crystallization studies. In facts, a much faster crystallization was found for PLA plasticized by PEG, which in turn indicates a much higher mobility of PLA chains above Tg compared to PLA plasticized by cardanol derivatives. Mechanical properties obtained on completely amorphous samples show that PLA plasticized by ECA is characterized by lower modulus, which is indicative of a more efficient plasticization. On the other hand, the thicker crystals formed during crystallization of PLA plasticized by ECA involve a more relevant increase in the modulus in semicrystalline samples.

Effect on Polymer Chain Structure Caused by the Molar Fraction of 4-Hydroxybutyrate in Poly(3-hydroxybutyrate- co -4-hydroxybutyrate)

2012 ◽  
Vol 602-604 ◽  
pp. 776-780
Author(s):  
Zhi Qiang Li ◽  
Mei Li ◽  
Wei Jia Fan
Keyword(s):  
Molecular Weight ◽  
Intrinsic Viscosity ◽  
Polymer Chain ◽  
Molar Fraction ◽  
Chain Structure ◽  
The Other ◽  
Mean Square ◽  
Polarizing Microscope ◽  
Other Hand ◽  
The Mean

Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)copolymer [P(3HB-co-4HB)] is a kind of biodegradable high molecular polymer produced by bioaccumulation. Because of the good biodegradability and biocompatibility, P(3HB-co-4HB)s have attracted wide attention . At first, the intrinsic viscosity[η] in good solvent of P(3HB-co-4HB) s with varying contents of 4HB was investigated in different temperature. Second, observed the changes of crystallization gathered state caused by the varying contents of 4HB by polarizing microscope. The results show that to the P(3HB-co-4HB)s in same molecular weight, the intrinsic viscosity[η] in good solvent barely changes when the mole fractions of 4HB increase. On the other hand, the mean square end to end distances[0] of macromolecular flexible chains increase with the mole fractions of 4HB. At the same time, the states of aggregation change from spherulites to dendrites. In this investigation, we discuss the reasons of the differences in depth.

Reactions of polar dienes with o-quinones

1989 ◽  
Vol 67 (8) ◽  
pp. 1354-1358 ◽  
Author(s):  
Jacques Paquet ◽  
Paul Brassard
Keyword(s):  
The Other ◽  
Other Hand ◽  
Wide Range ◽  
Ketene Acetal

The behaviour of various types of polar dienes towards halogenated ortho quinones has been investigated in a number of representative cases. As compared to the commonly used para analogues, o-quinones provide a wide range of products that indicate a keener response to the nature, number, and position of substituents on both reactants. 3-Halogenated-o-naphthoquinones 1 and 2 react smoothly with a representative vinologous ketene acetal 3, vinylketene acetals 4 and 5, and a monooxygenated diene 6 to provide variously substituted phenanthrenequinones 7–11. Only monooxygenated dienes on the other hand add to o-benzoquinones 14–16 and give convenient syntheses of the corresponding o-naphthoquinones 18–20. Keywords: cycloaddition, o-naphthoquinones, phenanthrenequinones, regiospecificity.

The Council of Trent Revisited

2002 ◽  
Vol 55 (1) ◽  
pp. 1-37 ◽  
Author(s):  
Craig A. Monson
Keyword(s):  
The Other ◽  
Council Of Trent ◽  
Local Authorities ◽  
Other Hand ◽  
Wide Range ◽  
Official Status

Abstract Reexamination of a wide range of documents surrounding the twenty-second, twenty-fourth, and twenty-fifth sessions of the Council of Trent reveals that delegates strived officially to say as little as possible about music: only that secular or impure elements should be eliminated and that specific issues should be settled locally, by individual bishops and provincial synods. But, beginning with Gustave Reese, several scholars have misleadingly strung together a preliminary canon, stressing textual intelligibility, which was never approved in the general congregations, and the few lines that actually supplanted it, concerned only with the elimination of lasciviousness. On the other hand, a largely unrecognized or misunderstood attack on church polyphony did occur at the less familiar twenty-fifth session, when Gabriele Paleotti may have attempted to suppress elaborate music in female monasteries. Although this attempt was rejected in the general congregations, its restrictions were subsequently revived by local authorities such as Paleotti and Carlo Borromeo in their own dioceses. In the Council's immediate aftermath, reformers such as Paleotti and Borromeo once again focused on the issue of intelligibility, affording it a quasi-official status that seems to have quickly become widely accepted as “iuxta formam concilii.”

Diversification of α–Ketoamides via Transamidation Reactions with Alkyl and Benzyl Amines at Room Temperature

2021 ◽  
Author(s):  
Shweta Singh ◽  
Sureshbabu Popuri ◽  
Qazi Mohammad Junaid ◽  
Sabiah Shahul Hameed ◽  
Jeyakumar Kandasamy
Keyword(s):  
Room Temperature ◽  
The Other ◽  
Alkyl Amines ◽  
Other Hand ◽  
Wide Range

A wide range of N-tosyl α–ketoamides underwent transamidation with various alkyl amines in the absence of catalyst, base, or additives. On the other hand, transamidation in N-Boc α–ketoamides is achieved...

scholarly journals Złożenie skargi przez konsumenta za pośrednictwem ODR (Online Dispute Resolution) – internetowego systemu rozstrzygania sporów

2019 ◽  
Vol 17 (1) ◽  
pp. 183-194
Author(s):  
Anna Rogacka-Łukasik
Keyword(s):  
Dispute Resolution ◽  
Alternative Dispute Resolution ◽  
The Other ◽  
Online Dispute Resolution ◽  
Other Hand ◽  
Resolution System ◽  
Wide Range ◽  
Technical Innovations ◽  
Modern Form ◽  
Dispute Resolution System

ADR (Alternative Dispute Resolution), as a non-judicial resolution of disputes, is a wide range of mechanisms that aim to put an end to a conflict without the need of conducting a trial before the court. On the other hand, the modern form of ADR is ODR (Online Dispute Resolution) – an online dispute resolution system that is the expression of the newest means of communication and technical innovations in order to help in non-judicial dispute resolving. The goal of this publication is to present the ODR platform and, in particular, to describe the process of filing a complaint by the consumer by means of it.

scholarly journals Hegel’s Lectures on the History of Modern Philosophy

2017 ◽  
Author(s):  
Karin de Boer
Keyword(s):  
Modern Philosophy ◽  
History Of Philosophy ◽  
The Other ◽  
Other Hand ◽  
Wide Range ◽  
History Of ◽  
Methodological Principles ◽  
The One

This chapter examines Hegel’s lectures on the history of modern philosophy in view of the tension between, on the one hand, his ambition to grasp philosophy’s past in a truly philosophical way and, on the other hand, the necessity to account for the actual particularities of a wide range of philosophical systems. Hegel’s lectures are put in relief by comparing their methodological principles to those put forward by his Kantian predecessor Tennemann. After discussing Hegel’s conception of modern philosophy as a whole, the chapter turns to his reading of Locke, Leibniz, and, in particular, Kant. In this context, it also compares Hegel’s assessment of Kant’s achievements to that of Tennemann. The chapter concludes by considering Hegel’s account of the final moment of the history of philosophy.

The Political Function of the Poro. (Part II.)

Africa ◽  
1966 ◽  
Vol 36 (1) ◽  
pp. 62-72 ◽  
Author(s):  
Kenneth Little
Keyword(s):  
The Other ◽  
The Political ◽  
Other Hand ◽  
Political Function ◽  
Wide Range ◽  
Opening Paragraph

Opening ParagraphIn the concluding paragraphs of Part I of this article it was pointed out that in addition to its judicial functions the Poro society possessed some important powers of administration. On the other hand, there was also evidence to suggest that the society carried on this wide range of activities, amounting almost to government of the country, as an instrument of the chiefs.

Solution Autoxidation of EPDM and Termonomers

1972 ◽  
Vol 45 (4) ◽  
pp. 1125-1135
Author(s):  
H. Schnecko ◽  
J. S. Walker
Keyword(s):  
Activation Energy ◽  
Molecular Weight ◽  
Oxygen Uptake ◽  
The Other ◽  
Low Molecular Weight ◽  
Kinetic Behavior ◽  
Ethylene Propylene ◽  
Very High

Abstract Oxygen uptake of 3 low molecular weight ethylene-propylene terpolymers (EPDM) and their respective bicyclic diolefin termonomers (dicyclopentadiene, ethylidene norbornene, and methyl endomethylene hexahydronaphthalene) has been measured at ⩽70°. From the kinetic behavior and from the activation energy, it has been concluded that ethylidene norbornene reacts differently from the other two monomers; its autoxidation is much slower. In all cases, conversion is not very high due to formation of an unidentified inhibitor.

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