Degree of comonomer inclusion into lamella crystal for propylene/olefin copolymers

Hosoda, Satoru; Hori, Hideaki; Yada, Ken-ichiro; Nakahara, Shinya; Tsuji, Mitsuji

doi:10.1016/s0032-3861(02)00680-8

Cited by 83 publications

(132 citation statements)

References 37 publications

Supporting

Mentioning

122

Contrasting

Order By: Relevance

“…It has been observed that the methyl and, to a lesser extent, ethyl branches can be included in the crystallites, due to their small sizes, while propyl and longer branches are completely excluded. [5][6][7][8] Using solid state NMR, White and co-workers 9 also reported an increase in the interfacial content (i.e. "constrained amorphous" plus "mobile all-trans" fractions) with increasing co-monomer content.…”

Section: Introductionmentioning

confidence: 98%

Effect of Short Chain Branching on the Interlamellar Structure of Semicrystalline Polyethylene

2017

View full text Add to dashboard Cite

We use molecular simulations with a united atom force field to examine the effect of short chain branching (SCB) on the noncrystalline, interlamellar structure typical of linear low density polyethylene (LLDPE). The model is predicated on a metastable thermodynamic equilibrium within the interlamellar space of the crystal stack and accounts explicitly for the various chain topologies (loops, tails, and bridges) therein. We examine three branched systems containing methyl, ethyl, and butyl side branches, and compare our results to high density polyethylene (HDPE), without branches. We also compare results for two united atom force fields, PYS and TraPPE-UA, within the context of these simulations. In contrast to conventional wisdom, our simulations indicate that the thicknesses of the interfacial regions in systems with SCB are smaller than those observed for a linear polyethylene without branches, and that branches are uniformly distributed throughout the interlamellar region. We find a prevalence of gauche states along the backbone due to the presence of branches, and an abrupt decrease in the orientational order in the region immediately adjacent to the crystallite.3 Introduction:

show abstract

Section: Introductionmentioning

confidence: 98%

Effect of Short Chain Branching on the Interlamellar Structure of Semicrystalline Polyethylene

2017

View full text Add to dashboard Cite

show abstract

“…[35][36][37][38][39][40] Ethylene comonomer, due to its small size, is not excluded from the crystal lattice, but it interrupts the iPP helix, shortening the crystal sequence and incorporating these distorted sequences to the amorphous fraction of the polymer. [37,41,42] Figure 1a also shows the totally amorphous profile, amPP, of an elastomeric PP sample [30] , in this case scaled to account for the amorphous component corresponding to the terpolymer. By subtraction of this amorphous component (adequately scaled for each sample), the pure crystalline profiles (shown in figure 1b) can be obtained, as well as the overall X-ray degree of crystallinity, f cTOTAL .…”

Section: Experimental Partmentioning

confidence: 99%

Influence of structure on the properties of polypropylene copolymers and terpolymers

et al. 2017

View full text Add to dashboard Cite

A set of Ziegler-Natta copolymers of iPP with ethylene or with 1-butene, and terpolymers with both counits have been characterized, devoting special attention to the effect of composition and processing conditions on the crystal structure and on the final properties.DSC and X-ray diffraction is used to study the polymorphism of copolymers and terpolymers.Comonomer insertion interrupts the isotactic sequences, acting as a structural defect, and the formation of  form is enhanced in the interval of studied compositions. Moreover, crystallinity decreases and crystal structure is modified. Comonomer type and concentration determine the extent of these modifications, resulting on important changes in macroscopicproperties. An important aspect to be considered is the higher ability of 1-butene units to be incorporated in the iPP crystals in relation to ethylene counits. From the balance of different properties, possible applications are suggested for the various types of samples. For instance, the excellent optical properties of the analyzed terpolymers make them very attractive for applications such as transparent film or packaging.

show abstract

“…However, if the chain length of the comonomer is closer to the main monomer, the impact would become weak. The change of the melting temperature of the propylene copolymer with 1-butene [36], 1-hexene [37,38], 1-octene [37] and 1-decene [37] showed that, the incorporation of the shorter comonomer would be less efficient to decrease the melting temperature of the copolymer. Previous research revealed that 1-butene was more inclined to be incorporated into the crystalline phase than ethylene, 1-hexene and 1-octene for propylene copolymers [39].…”

Section: Thementioning

confidence: 99%

Copolymerization of 4-methyl-1-pentene with α,ω-alkenols

Wang¹,

Hou²,

Sheng³

et al. 2016

Express Polym. Lett.

View full text Add to dashboard Cite

Abstract. Copolymerization of 4-methyl-1-pentene (4M1P) with 9-decen-1-ol (9D1O) or 4-penten-1-ol (4P1O) was conducted by using metallocene catalysts. The activity could be improved under the higher polymerization temperature. The dyad distribution of poly(4M1P-co-4P1O) was presented. The results showed that 4P1O was uniformly distributed in the copolymer chain. The melting temperature (T m ) of the copolymer was lower than that of poly(4M1P), and was decreased with the increase of the incorporation of comonomer. T m of poly(4M1P-co-4P1O) was determined as 185°C, even the incorporation of 4P1O was high as 15.0 mol%. WAXD (wide-angle X-ray diffraction) results showed that the poly(4M1P) was observed as crystalline form II, and turned to form I when the incorporation of α,ω-alkenols were high. Some new peaks, which were never observed in the previous researches, appeared in the X-ray diffraction profiles for poly(4M1P-co-4P1O). It is inferred that the similar chain length of 4P1O and 4M1P may be the key factor.

show abstract

Degree of comonomer inclusion into lamella crystal for propylene/olefin copolymers

Cited by 83 publications

References 37 publications

Effect of Short Chain Branching on the Interlamellar Structure of Semicrystalline Polyethylene

Effect of Short Chain Branching on the Interlamellar Structure of Semicrystalline Polyethylene

Influence of structure on the properties of polypropylene copolymers and terpolymers

Copolymerization of 4-methyl-1-pentene with α,ω-alkenols

Contact Info

Product

Resources

About