Miscibility, crystallization and melting behaviour and semicrystalline morphology of ternary blends of poly(ε-caprolacton), poly(hydroxy ether of bisphenol A) and poly(styrene-co-acrylonitrile): 2. Semicrystalline morphology

Vanneste, Myriam; Groeninckx, Gabriël; Reynaers, Harry

doi:10.1016/s0032-3861(96)01033-6

Cited by 15 publications

(15 citation statements)

References 22 publications

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“…This fact is indication of the interfibrillar segregation because PS molecules of the PS‐rich phase can diffuse over large distances during the lamellar growth process of PCL. This long range diffusion results in an interfibrillar as well as interspherulitic segregation of the amorphous polymers at low PCL concentration . The behavior of l c , l a , and L as a function of PS content in the blend is similar to that reported by Nojima et al in blends of PCL with PSO that has .…”

Section: Resultssupporting

confidence: 83%

“…The crystallization implies the segregation of amorphous polymer chains and, depending on the distance of segregation, different types of morphology can coexist in the system; this includes: interlamellar (amorphous chains between lamellae), interfibrillar (amorphous chains between lamellar bundles or stacks of lamellae), and interspherulitic (amorphous chains between spherulites) segregation . The last case of segregation can be called intraspherulitic because one distinguishes of other two types and implies the creation of droplets of the amorphous almost pure component .…”

Section: Introductionmentioning

confidence: 99%

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Phase separation and segregation morphology of PCL/PS blends: Quantitative effect of the crystallization temperature, composition, and molecular weight of PS

Silva

Rojo

Riccardi

2016

Polymer Engineering & Sci

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The phase diagrams for blends of semicrystalline poly(ecaprolactone) (PCL) with amorphous polystyrene (PS) were determined and it was noticed that when molecular weight increases, the critical composition diminishes while its temperature increases. That is the same effect that produces the increase in the polydispersity of PS. From the fitting of phase diagrams of blends of PCL with oligomers and homopolymers of PS, taking into account the polydispersity, it was possible to conclude that the miscibility in these systems is due only by entropic effects. The crystalline fraction as well as the interlamellar spacing increased with crystallization temperature while the volume fraction of the amorphous PCL in the interfibrillar regions increases for the pure PCL and in its blends with low concentration of PS. Increasing the mass fraction of PS increases the average long spacing (L) till a weight fraction of 60%, for higher mass fractions L is almost constant indicating the interfibrillar segregation of PS. The PCL lamellar morphology is not affected when the molecular weight of PS employed is similar or higher than the molecular weight of PCL. If the PS has a higher molecular weight its penetration into the structure is inhibited.

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Section: Resultssupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Phase separation and segregation morphology of PCL/PS blends: Quantitative effect of the crystallization temperature, composition, and molecular weight of PS

Silva

Rojo

Riccardi

2016

Polymer Engineering & Sci

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“…The value of Φ c is assumed as the mass crystallinity and estimated from the melting enthalpy by the DSC measurement; however, this method is the unreliable for linear crystallinities in the range from roughly 0.3 to 0.7. For PCL blend systems, it is widely accepted that the crystal phase is assigned to the thicker length 33–36. Furthermore, for a similar blend system (PCL/4,4′‐thiodiphenol), it has been indicated that, if L 1 is assigned to L c , the linear crystallinity is smaller than bulky crystallinity, which has no physical significance 37.…”

Section: Resultsmentioning

confidence: 99%

Thermal behavior and phase morphology of miscible hydrogen‐bonded blends of poly(ϵ‐caprolactone) and enzymatically polymerized polyphenol

Fukuoka

et al. 2006

J of Applied Polymer Sci

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Enzymatically prepared novel polyphenol poly(4,4Ј-dihydroxydiphenyl ether) (PDHDPE) is blended to modify the properties of biodegradable polyester poly(-caprolactone) (PCL). Since the differential scanning calorimetry data show single composition-dependent glass transition for each blend, PCL and PDHDPE are found to be miscible in the amorphous phase. The crystallization of PCL is depressed by PDHDPE because PDHDPE reduces the molecular mobility and the flexibility of molecular chains of PCL. The Fourier transform infrared spectra clearly indicate that PCL and PDHDPE interact through strong intermolecular hydrogen bonds formed between the carbonyl groups of PCL and the hydroxyl groups of PDHDPE. The increase of the long period, calculated on the basis of Bragg's law with the measurement of small-angle X-ray scattering, is found because the peak position of the profiles of Lorentzcorrected intensity shifts to smaller angle. With the help of lamellar stack model and one-dimensional correlation function, the accurate lamellar parameters are calculated. The increase of long period is induced by the increase of crystal thickness. The thermal treatment can effectively modify the thermal stability of PCL/PDHDPE blends with the introduction of an intermolecular coupling of the polymer to give crosslinked and/or branched products. It is also found that the addition of PDHDPE to PCL would obviously increase the Young's modulus of PCL.

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“…The l 1 and l 2 can be assigned to l a and l c , respectively, according to the previous SAXS studies of PCL blends. [14][15][16][17][18] The values of l c , l a , and L obtained from Figure 3 are tabulated in Table II. It can be seen that l a in the blends is about 1.2-1.8 nm thinner than that in neat PCL, implying that at least a portion of PVC was expelled out of the interlamellar region upon PCL crystallization.…”

Section: Saxs Measurementsmentioning

confidence: 99%

Nonisothermal Crystallization of Compatible PCL/PVC Blends under Supercritical CO2

Shieh

Yang

Chen

et al. 2005

Polym J

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ABSTRACT:Nonisothermal crystallizations of polycaprolactone (PCL) in the presence of poly(vinyl chloride) (PVC) at a cooling rate of 0.5 C/min from 90 to 30 C under supercritical CO 2 at a constant pressure 304 atm were investigated. DSC and SAXS data found that the nonisothermal crystallizations of the PCL/PVC blends under supercritical CO 2 resulted in decrease in thickness of the crystalline layers in the lamellar stacks. These nonisothermal supercritical CO 2 treatments also generated a morphological heterogeneity with size (13.8 nm for pure PCL) larger than the long period (12.1 nm) of the lamellar stacks. 4 Polymers subjected to the supercritical CO 2 fluids may result in melting temperature depressions, 5,6 phase separations, 7 or morphological changes. 5,[8][9][10] Since crystallization of a polymer leads to a morphology that can determine its final physical properties, it is important to reveal the crystallization behavior of the polymer under supercritical CO 2 fluids before these fluids can be practically used for processing of the polymer.Poly("-caprolactone) (PCL) is a crystalline and biodegradable aliphatic polyester having a glass transition temperature of about À60 C and a melting temperature of about 60 C. In a previous study, 10 we investigated the morphological changes of PCL under isothermal (35 C) high-pressure (36, 84, and 304 atm) CO 2 treatments by means of DSC and SAXS. It was found that PCL melted under 84 and 304 atm of CO 2 at 35 C, a much lower temperature than T m of PCL. The CO 2 -assisted melting of PCL recrystallized during depressurization of CO 2 , resulting in a varied thickness of crystal layers and amorphous layers with CO 2 pressures. This report presents a continuing study of our previous work. 10 This work aims at the nonisothermal crystallization behavior of PCL under supercritical CO 2 at a constant pressure 304 atm at a cooling rate of 0.5 C per min from 90 C to 30 C in the presence of various amounts of PVC. It will be seen from DSC and SAXS data that the nonisothermal crystallizations of the PCL/PVC blends under supercritical CO 2 result in decrease in thickness of crystalline layers of the lamellar stacks. Heterogeneity, with a size larger than the long period, is formed after nonisothermal crystallizations under supercritical CO 2 .

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Miscibility, crystallization and melting behaviour and semicrystalline morphology of ternary blends of poly(ε-caprolacton), poly(hydroxy ether of bisphenol A) and poly(styrene-co-acrylonitrile): 2. Semicrystalline morphology

Cited by 15 publications

References 22 publications

Phase separation and segregation morphology of PCL/PS blends: Quantitative effect of the crystallization temperature, composition, and molecular weight of PS

Phase separation and segregation morphology of PCL/PS blends: Quantitative effect of the crystallization temperature, composition, and molecular weight of PS

Thermal behavior and phase morphology of miscible hydrogen‐bonded blends of poly(ϵ‐caprolactone) and enzymatically polymerized polyphenol

Nonisothermal Crystallization of Compatible PCL/PVC Blends under Supercritical CO2

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