Mechanism of the short chain branching in low density polyethylene

Stoiljkovich, D.; Jovanovich, S.

doi:10.1002/macp.1981.021821026

Cited by 21 publications

(10 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…8) and amount 127.6, 63.8 and 40 cm 3 /mole for the molecular pair, the bimolecule and the oligomolecule, respectively. These values are very [18][19][20][21][22][23] close to the empirical values for these particles: 127.6, 57.1 and 37.8 cm 3 /mole, respectively. The existence of these particles and the higher order phase transitions in compressed ethylene have been confirmed by the thermodynamic, physical and spectroscopic methods.…”

Section: Free Radical Polymerization Of Compressed Ethylene Gassupporting

confidence: 76%

Importance of Boscovich's theory of natural philosophy for polymer science

Stoiljkovic¹

2007

Polimery

View full text Add to dashboard Cite

It has been generally accepted that the macromolecular hypothesis was for the first time presented by H. Staudinger (1920). It is shown in this article, however, that Roger Boscovich, in his monumental work "Theory of natural philosophy", as early as in the 18th century, pointed out that the spiral atomic chains could be formed. He also pointed that the shape of the chain could be markedly changed due to slight changes of the distances among the atoms. The elastic properties of the chains have been stressed. The author of this article also presented some examples of the applications of Boscovich's theory for the interpretation of free-radical polymerization of compressed ethylene gas and liquid methyl methacrylate. The priority of Boscovich's macromolecular hypothesis is doubtless and his theory is still applicable in the current polymer science.

show abstract

Section: Free Radical Polymerization Of Compressed Ethylene Gassupporting

confidence: 76%

Importance of Boscovich's theory of natural philosophy for polymer science

Stoiljkovic¹

2007

Polimery

View full text Add to dashboard Cite

show abstract

“…Neither of these parameters can represent the supermolecular organisation of ET. Taking the pressure and temperature from the published experiments, we have determined the entropy of ET under synthesis conditions using the well known diagram of Benzler and Koch.19 In this paper the published data are compiled and presented in relation to ET entropy (Figs 2,3 ,4,6,8,9,11,12 and 13 and Tables 2 and 3). In some figures (5, 10, 1 1 , 12 and 14) the designation of the phase state of ET @, y, P-y transition) under synthesis conditions is made.…”

Section: Experimental Datamentioning

confidence: 99%

“…In this case, all published data about the effect of synthesis conditions on SCB should fit a common curve. 8 The curve is presented in Fig. 3 and its matehmatical expression is given by Eq.…”

Section: Short Chain Branchingmentioning

confidence: 99%

Origin of the molecular structure and properties of low density polyethylene

Stoiljkovic

Jovanović

1984

Brit. Poly.J.

View full text Add to dashboard Cite

It is generally accepted that the origin of the structural features of low density polyethylene (branching, unsaturation, molar mass and its distribution) can be explained by various isomerisation and decomposition reactions of the macroradicals and by various chain transfer processes. On the other hand, it is known that ethylene molecules under high pressure are organised in various supermolecular particles. There are several phases in compressed ethylene (a, 0 and y) depending on the pressure and temperature. The purpose of the present work was to determine the effects of the phase state of ethylene on the structure and properties of polyethylene. The authors have compiled published data about the effects of the synthesis pressure and temperature on the structure and properties of polyethylene. The entropy of ethylene under sythesis conditions for those published experiments was determined from the available information on pressure and temperature. The effects of ethylene entropy on the number and type of short chain branches, long chain branches, unsaturated bonds, molar mass and its distribution, chain flexibility, density and the melting point of polyethylene are demonstrated. It was found that under given ethylene entropy conditions, the same structure and properties of polyethylene are obtained.

show abstract

“…This is somewhat surprising as the cornerstones of this class of polymers -polyethylene ( Fig. 2: PE; x = 0, y = 2) [40][41][42][43][44] and poly(p-phenylene) ( Fig. 2: PPP; x = 1, y = 0) 5,45) -are very important exponents or model polymers in their respective fields of applications.…”

Section: Introductionmentioning

confidence: 99%

Poly(p-phenylene alkylene)s – A forgotten class of polymers

Steiger

Tervoort

Weder³

et al. 2000

Macromol. Rapid Commun.

View full text Add to dashboard Cite

Within the wealth of hydrocarbon polymers, poly(p‐phenylene alkylene)s (“alkarotics”) hold a special position since they have been a long forgotten class of hydrophobic polymers. This is somewhat surprising, since the cornerstones of this polymer family cover extremely broad materials properties and the few known representatives attract attention with very favorable characteristics. In the course of this article, four new representatives of this family are presented. Whereas poly(p‐phenylene octylene) (PPPO; 90°C), poly(p‐phenylene hexylene) (PPPH; 120°C) and poly(p‐phenylene propylene) (PPPPr; 110–130°C) have surprisingly low melting temperatures, the highly crystalline poly(p‐phenylene butylene) (PPPB), melting between 200 and 225°C, meets many of the requirements that are essential for a novel, hydrophobic, processable, engineering polymer. In connection with the efforts to tailor the melting temperature of these polymers, a simple, semi‐empirical methodology to estimate melting temperatures of unknown representatives of homologous series of polymers was developed and verified. By means of this approach, the melting temperatures of PPPH and PPPB could be predicted with remarkable accuracy. In addition, it was shown that the method is not restricted to the present alkarotic polymers, but it seems to have a rather broad range of applications as shown by the successful description of the polymer series, including various liquid‐crystalline hydrocarbon polymers and different polyamides.

show abstract

Mechanism of the short chain branching in low density polyethylene

Cited by 21 publications

References 28 publications

Importance of Boscovich's theory of natural philosophy for polymer science

Importance of Boscovich's theory of natural philosophy for polymer science

Origin of the molecular structure and properties of low density polyethylene

Poly(p-phenylene alkylene)s – A forgotten class of polymers

Contact Info

Product

Resources

About