Small-angle neutron scattering study of the miscibility of metallocene-catalyzed octene linear low-density polyethylene and low-density polyethylene blends

Shin, Tae Joo; Lee, Byeongdu; Lee, Jinwon; Jin, Seunghun; Sung, Baik Shuk; Han, Young Soo; Lee, Changhee; Stein, Richard S.; Ree, Moonhor

doi:10.1107/s0021889809002854

Cited by 12 publications

(3 citation statements)

References 64 publications

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“…Although polydienes and polyolefins both have important elastomeric applications, , few systematic thermodynamic studies have been carried out on polydiene–polyolefin blend systems. Polydiene–polydiene , and polyolefin–polyolefin − blends typically display low χ values, indicating high compatibility. On the other hand, polyolefin–polydiene blendshigh-vinyl polybutadiene/saturated high-vinyl polybutadiene, polyisoprene/saturated high-vinyl polybutadiene, and polyisoprene/saturated polyisopreneshow a large and strongly temperature-dependent χ.…”

Section: Introductionmentioning

confidence: 99%

Incorporation of Styrene into a Model Polyolefin for Enhanced Compatibility with Polyisoprene

Jangareddy

2020

Macromolecules

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Polyisoprene (PI) and hydrogenated medium-vinyl polybutadiene (hPB), a polydiene–polyolefin pair, are expected to show limited compatibility (with a high interaction energy density, X, proportional to the Flory interaction parameter, χ). The regular mixing model suggests that styrene (S) units can boost the interblock compatibility when incorporated in small amounts into the hPB chain via random copolymerization. The mixing thermodynamics in symmetric polydiene–polyolefin “block–random” copolymers composed of PI and a random copolymer of styrene and hydrogenated medium-vinyl butadiene (hSBR) were investigated, through measurements of the order–disorder transition temperature. Block and block–random copolymers were prepared by anionic polymerization, followed by selective saturation of the butadiene units. More than a 2-fold decrease in X was achieved on incorporating ∼20 wt % S in the random block, with a further decrease observed at ∼30 wt % S incorporation, indicating a strong enhancement in compatibility. At higher styrene contents, X varied parabolically as qualitatively predicted by the regular mixing model, but better quantitative agreement was obtained with the copolymer equation model.

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Section: Introductionmentioning

confidence: 99%

Incorporation of Styrene into a Model Polyolefin for Enhanced Compatibility with Polyisoprene

Jangareddy

2020

Macromolecules

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“…Polydienes and polyolefins are dominant materials employed in elastomer applications, such as sealants, rubber tires, adhesives, and impact modifiers, among others. Blends of polydienes generally exhibit small χ parameters with weak temperature dependencies, such as in the case of polybutadiene mixtures, , and blends of polybutadienes with polyisoprenes. , Interactions in blends of polyolefins have been extensively studied, and generally they also exhibit small and weakly temperature-dependent χ parameters, such as in the case of blends of saturated polybutadienes (with ∼10–20% differences in 1,2-polybutadiene content between blend components); − blends of saturated polybutadienes and saturated polyisoprenes; , polypropylene-based blends; − blends of various types of polyethylenes, or polyethylene mixed with saturated polyisoprene, poly(1-hexene), poly(1-butene), or poly(1-octene); − polyisobutylene-based blends; and blends of olefin oligomers . An important exception is the blend composed of saturated polybutadiene with 7% 1,2-addition and saturated polybutadiene with 90% 1,2-addition, which exhibited a χ parameter with a much stronger temperature dependence .…”

Section: Introductionmentioning

confidence: 99%

Thermodynamic Interactions in a Model Polydiene/Polyolefin Blend Based on 1,2-Polybutadiene

et al. 2018

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Thermodynamic interactions in polydiene/polyolefin blends composed of 1,2-polybutadiene (1,2-PBD) and fully saturated (with deuterium) 1,2-PBD were explored with small-angle neutron scattering (SANS). Two methods were employed to extract the temperature dependence of the Flory− Huggins interaction parameter, χ, from SANS data obtained in the single-phase region. First, Zimm analysis was conducted employing data obtained at low scattering angles, providing a model-independent method of characterizing χ. Next, the random phase approximation was fit to the full angle-dependent absolute scattering intensity. The χ parameter for 1,2-PBD/ saturated 1,2-PBD was found to be large in magnitude at low temperatures and exhibited a strong temperature dependence. The experimentally measured χ, at high temperatures, was in agreement with predictions of solubility parameter theory based on PVT properties of the individual components. The large and strongly temperature-dependent χ parameter of the 1,2-PBD/saturated 1,2-PBD mixture is an attractive feature enabling facile material processing and is in stark contrast to behavior observed in more traditionally studied polyolefin/polyolefin and polydiene/polydiene pairs.

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“…Elastomeric polymer mixtures constitute an important class of polymer blends due to their widespread use in adhesives, tires, sealants, and so forth. , While several studies have been made on the mixing behavior of elastomers where the component polymers are from the same chemical group (polydiene/polydiene or polyolefin/polyolefin systems), ,,− far fewer systematic studies exist on blends of polymers across these chemical groups (polydiene/polyolefin systems) owing to their relative incompatibility. − In our earlier work on PI–hSBR block copolymers, we showed that random incorporation of small amounts of styrene (S) into a hydrogenated polybutadiene (hPB) (model polyolefin) block enhances its compatibility with PI (reduces X ) significantly. We also showed that the experimental variation in X with the styrene content is well-explained by a simple mixing treatment, the CEM ,,,− where φ S is the volume fraction of styrene in the hSBR block and X i – j are the pair-wise interaction energy densities independently determined from block copolymers.…”

Section: Introductionmentioning

confidence: 99%

Blends of Polyisoprene with Model Styrene–Olefin Copolymers: Mixing Energetics in Blends versus Block Copolymers

et al. 2021

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Most theoretical treatments of polymer mixing thermodynamics assume that the phase behavior of both polymer blends and block copolymers is controlled by the same Flory segmental interaction parameter, χa quantity which is proportional to the interaction energy density, X. However, there are few comparative experimental studies on this point. This work presents a systematic experimental comparison between the interaction energy densities measured on model polydiene−polyolefin blends (X blend ) and analogous block copolymers (X BC ). Experimental cloud point temperature (T cl ) curves for blends of polyisoprene (PI) with selectively saturated poly(butadiene-r-styrene) (hSBR) random copolymers are fit to the Flory−Huggins theory, and the resultant values of X blend are corrected for critical fluctuations and for end-group contributions, wherever significant. The temperature-dependent PI/hSBR X blend (T) and previously reported PI−hSBR X BC values show satisfactory agreement at all levels of styrene incorporation, reinforcing the conclusion that random incorporation of styrene units into the saturated polybutadiene chain significantly enhances its compatibility with PI.

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Small-angle neutron scattering study of the miscibility of metallocene-catalyzed octene linear low-density polyethylene and low-density polyethylene blends

Cited by 12 publications

References 64 publications

Incorporation of Styrene into a Model Polyolefin for Enhanced Compatibility with Polyisoprene

Incorporation of Styrene into a Model Polyolefin for Enhanced Compatibility with Polyisoprene

Thermodynamic Interactions in a Model Polydiene/Polyolefin Blend Based on 1,2-Polybutadiene

Blends of Polyisoprene with Model Styrene–Olefin Copolymers: Mixing Energetics in Blends versus Block Copolymers

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