Analysis of the Thermal Behavior of Polypropylene–Camphor Mixtures for Understanding the Pathways to Polymeric Membranes via Thermally Induced Phase Separation
Abstract:An experimental phase diagram of the isotactic polypropylene−camphor system is constructed using an original optical method. It considerably deviates from the dynamic diagram, which can be obtained using conventional differential scanning calorimetry (DSC), and contains an additional boundary line that describes camphor solubility in the polymer. An accurate phase diagram makes it possible to perform a detailed and consistent thermodynamic analysis of the DSC, optical, and scanning electron microscopy data on … Show more
“…Fig. 8 in 22 ). Figure 1 Scanning electron microscopy (SEM) images of the polypropylene foam structures obtained from the plastic produced with weight ratio of camphene and camphor and weight ratio of polypropylene ( a , b , c ) with the foam made using the plastic containing weight ratio of camphene and camphor and weight ratio of polypropylene ( d , e , f ).…”
Section: Resultsmentioning
confidence: 97%
“…The components were added to a beaker along with a magnetic stirrer and placed on a hot plate set to 250 C. We dissolved 5 or 10% (higher concentrations are possible) of polypropylene by weight in a liquid camphene-camphor mixture at temperatures below 250 °C. Therefore, in our experiments the polymer is dissolved in the terpene mixture instead of the other way around as is described in other publications 22 .…”
Section: Methodsmentioning
confidence: 99%
“…Other methods include the use of porogens, which are substances evenly distributed in a polymer before leaching to leave behind a porous polymer lattice. Such porogens can be supercritical CO 2 20 , 21 or substances that are co-soluble in the polymer and can be removed by dissolution or thermally-induced phase separation 22 , 23 . One group of substances that has been recently applied for such purposes are terpenes which contain chemicals such as camphor, camphene or eukalyptol.…”
Section: Introductionmentioning
confidence: 99%
“…Terpenes offer a range of physical (volatility), chemical (co-solubility, plasticizing) and mechanical (crystalline, waxy or liquid) properties that are important for applied porogens. There are several papers reporting on the use of either camphor or camphene as porogens especially in thermally-induced phase separation (TIPS) for the production of microporous membranes 13 , 22 – 25 . In the majority of reported cases the terpene content was low compared to the polymer content leading to dense porous materials.…”
In a recently published paper (doi.org/10.3390/molecules26113116) on self-propelled motion of objects on the water surface, we described a novel surface-active plastic material obtained by dissolution of camphor and polypropylene in camphene at 250 $$^\circ$$
∘
C. The material has wax-like mechanical properties, can be easily formed to any moldable shape, and allows for longer and more stable self-propelled motion if compared with pure camphor or pure camphene or of a camphene-camphor wax. Here we use scanning electron microscopy to visualize and characterize the microporous structure of the solid polypropylene foam formed in the plastic for different polypropylene contents. The topology of foams remaining in the material after camphor and camphene molecules have been removed through evaporation or dissolution is similar to polypropylene foams obtained using thermally-induced phase separation. We show that the foams have a superhydrophobic surface but strongly absorb non-polar liquids, and suggest an array of potential scientific and industrial applications.
“…Fig. 8 in 22 ). Figure 1 Scanning electron microscopy (SEM) images of the polypropylene foam structures obtained from the plastic produced with weight ratio of camphene and camphor and weight ratio of polypropylene ( a , b , c ) with the foam made using the plastic containing weight ratio of camphene and camphor and weight ratio of polypropylene ( d , e , f ).…”
Section: Resultsmentioning
confidence: 97%
“…The components were added to a beaker along with a magnetic stirrer and placed on a hot plate set to 250 C. We dissolved 5 or 10% (higher concentrations are possible) of polypropylene by weight in a liquid camphene-camphor mixture at temperatures below 250 °C. Therefore, in our experiments the polymer is dissolved in the terpene mixture instead of the other way around as is described in other publications 22 .…”
Section: Methodsmentioning
confidence: 99%
“…Other methods include the use of porogens, which are substances evenly distributed in a polymer before leaching to leave behind a porous polymer lattice. Such porogens can be supercritical CO 2 20 , 21 or substances that are co-soluble in the polymer and can be removed by dissolution or thermally-induced phase separation 22 , 23 . One group of substances that has been recently applied for such purposes are terpenes which contain chemicals such as camphor, camphene or eukalyptol.…”
Section: Introductionmentioning
confidence: 99%
“…Terpenes offer a range of physical (volatility), chemical (co-solubility, plasticizing) and mechanical (crystalline, waxy or liquid) properties that are important for applied porogens. There are several papers reporting on the use of either camphor or camphene as porogens especially in thermally-induced phase separation (TIPS) for the production of microporous membranes 13 , 22 – 25 . In the majority of reported cases the terpene content was low compared to the polymer content leading to dense porous materials.…”
In a recently published paper (doi.org/10.3390/molecules26113116) on self-propelled motion of objects on the water surface, we described a novel surface-active plastic material obtained by dissolution of camphor and polypropylene in camphene at 250 $$^\circ$$
∘
C. The material has wax-like mechanical properties, can be easily formed to any moldable shape, and allows for longer and more stable self-propelled motion if compared with pure camphor or pure camphene or of a camphene-camphor wax. Here we use scanning electron microscopy to visualize and characterize the microporous structure of the solid polypropylene foam formed in the plastic for different polypropylene contents. The topology of foams remaining in the material after camphor and camphene molecules have been removed through evaporation or dissolution is similar to polypropylene foams obtained using thermally-induced phase separation. We show that the foams have a superhydrophobic surface but strongly absorb non-polar liquids, and suggest an array of potential scientific and industrial applications.
“…An original optical method that was described in detail earlier 27 and proved to be quite effective for different polymer–low‐molar‐mass substance systems 26–30 was used to construct the phase diagrams. It consists in monitoring through a horizontal microscope the effects of temperature changes on the state of a binary system placed into a sealed glass ampoule.…”
A detailed study of butyl rubber‐based vibration damping formulations linking their composition, morphology, phase structure, viscosity, mechanical loss factor, and other characteristics is presented for the first time. High performance of the compositions including aromatic petroleum oil is explained by limited solubility of the plasticizer that leads to the formation of a highly‐viscous emulsion (η20°C ≈ 1000 Pa·s) consisting of a swollen butyl rubber matrix and dispersed oil droplets in the broad composition range. Chalk is found to be the best inorganic filler as its spherical particles provide strong adhesion to the reinforcing layer of aluminum foil. Aiming to eliminate ecologically unfriendly aromatic compounds, a new low‐cost binding agent formulation based on butyl rubber mixed with polyisobutylene and highly refined mineral oil is suggested. Being environmentally safe, it possesses high viscosity of 1000–3000 Pa·s, cohesion strength of 3.5–5.0 N/cm, penetration of 4.5–6.0 mm, and mechanical loss factor up to 0.34 at room temperature, which are as good as, or even better than, the properties of currently produced vibration damping materials containing aromatic compounds. New materials can be used in car and aircraft parts for effective vibration isolation.
The purpose of this study was to reduce the severe shrinkage of the UHMWPE membrane during low‐concentration molding processing. In this study, using SiO2 inorganic particles as inner reinforced materials and copper fibers as core support bodies significantly improved the structural stability of the membrane. Compared with the UHMWPE membrane, the shrinkage of the length and diameter of the Cu@UHMWPE/SiO2 membranes decreased by 84% and 61%, respectively, and the pure water flux increased by 322%. Copper fiber as a support material reduced the shrinkage of the membrane and improved pore connectivity. The tensile strength of Cu@UHMWPE/SiO2 was 6.8 MPa. Additionally, the Cu@UHMWPE/SiO2 membrane exerted a better antifouling performance. This study provided a new method to improve the structural stability of the UHMWPE membrane.
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