共查询到20条相似文献,搜索用时 312 毫秒
1.
C. K. Lyon Vilma H. Garrett L. A. Goldblatt 《Journal of the American Oil Chemists' Society》1964,41(1):23-25
Solvent-blown rigid urethane foams prepared from a low-cost polyol mixture composed of raw castor oil and triisopropanolamine
have been described. Foams with higher compressive strengths can be obtained by substituting oxidized (blown) castor oil for
the raw castor oil in formulations of this type.
The properties of rigid foams prepared from several commercial blown castor oils are described. The properties of these foams
are correlated with the degree of oxidation of the blown oils used, as indicated by their oxygen content, density, viscosity,
and refractive index. Removal of acid from blown oils having high acid values has no significant effect on the compressive
strength of foams prepared from these oils.
When blown castor oil is used instead of raw castor oil, less isocyanate is required to produce a urethane foam of specified
density and compressive strength.
Presented at the AOCS meeting in Toronto, Canada, 1962.
A laboratory of the W. Utiliz. Res. & Dev. Div., ARS, U.S.D.A. 相似文献
2.
C. K. Lyon Vilma H. Garrett Leo A. Goldblatt 《Journal of the American Oil Chemists' Society》1961,38(5):262-266
The preparation of trichlorofluoromethane-blown rigid urethane foams using toluenediisocyanate and castor oil-derived polyols
was investigated. The castor-based polyols included castor oil, hydroxylated castor oil, technical glycerol-, penta-erythritol-,
and sorbitol monoricinoleates, and N,N-bis(2-hydroxyethyl) ricinoleamide.
The last of these yielded the best foams when used as the sole polyol component added to the prepolymer. However better foams
were obtained by using, as the polyol component, a mixture of a castor oil-derived polyol and a lower-molecular-weight polyol
with a higher hydroxyl content. These polyol mixtures yielded more highly cross-linked polymers and hence foams with higher
compressive strengths and less tendency to shrink after foaming.
The effect of catalyst, silicone surfactant, and trichlorofluoromethane content was also investigated. An empirical relationship
between density and compressive strength in a given foam system was derived.
Presented at the fall meeting, American Oil Chemists' Society, New York, October 17–19, 1960.
A laboratory of the Western Utilization Research and Development Division. Agricultural Research Service, U.S. Department
of Agriculture. 相似文献
3.
The effects of additives in various vegetable oils on the physical, mechanical, and adhesion properties of carbon black/rubber compounds were studied. Various doses of castor oil and some other oils such as paraffin oil, vegetable oil 1, and cashew nut shell liquid (CNSL) at a fixed dose (1 phr) were used. With an increase in the castor oil content, the modulus, tear strength, and tensile strength increased, whereas the hardness and adhesive strength exhibited little variation up to 1 phr. Beyond 1 phr castor oil, the modulus, tear strength, and hardness decreased, whereas the adhesive and tensile strengths increased up to 2.5–3 phr and then decreased. Therefore, castor oil seemed to behave as a coupling agent up to 1 phr and as a coupling agent and a plasticizer in the range of 1–3 phr; beyond that, the main role of castor oil was plasticization. When various oils at a fixed dose (1 phr) were compared, it was found that the vegetable oils exhibited enhanced properties in comparison with those of paraffin oil. In addition, both of the unsaturated oils (castor oil and vegetable oil 1) enhanced physical and mechanical properties in comparison with saturated paraffin oil. CNSL exhibited the best adhesion properties against mild steel and galvanized iron substrates. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1574–1578, 2003 相似文献
4.
D. A. Yeadon A. R. Markezich L. A. Goldblatt 《Journal of the American Oil Chemists' Society》1959,36(11):541-545
Summary The preparation and properties of two series of castor oil urethane foams, one from castor oil and the other from elaidinized
castor oil, were investigated. The first series of foams was made from prepolymers containing 60% of castor oil prepared at
increasing temperature levels to vary the degree of crosslinking in the final foams. These foams had lower tensile strengths
than observed for a previously prepared foam of 60% castor oil and did not show significant differences in water resistance
as crosslinking varied. They were increased nearly 100% in compressive strength with increased crosslinking and had very good
shrinkage characteristics as values of only 1 to 2% were obtained.
A second series of foams was prepared from 50, 60, 70, and 80% of elaidinized castor oil to compare with foams from a similar
series from castor oil. This series of foams of 50 to 80% elaidinized castor oil contents was similar in density (1.7 to 6.7
lbs./cu. ft.), had improved shrinkage characteristics (11, 1, 3, and 4%, respectively), showed increased compressive and tensile
strengths (up to 12.1 p.s.i. at 50% compression modulus and 34.7 p.s.i. ultimate tensile for the 60% foam formulation), and
had better water-resistance properties (411 to 155%vs. 515 to 170% water absorption) than the analogous foams from castor oil. In general, humid aging only slightly affected the
values obtained for the foams and was significant in only a few instances,e.g., decreased tensile in the elaidinized castor oil series.
Thus increasing crosslinks in the foam apparently did not improve water resistance but did improve shrinkage characteristics
in addition to some increased strength properties, as would be anticipated. Foams from elaidinized castor oil, while similar
in density and foaming characteristics to analogous foams from castor oil, exhibited less shrinkage and improved water-resistance.
Presented at the 50th Annual Meeting of the American Oil Chemists' Society, New Orleans, La., April 20–22, 1959.
Ono of the laboratories of the Southern Utilization Research and Development Division, Agricultural Research Service, U. S.
Department of Agriculture. 相似文献
5.
Urethane elastomers with a wide range of properties were prepared by reaction of toluene diisocyanate, diphenylmethane diisocyanate
or an aliphatic diisocyanate with a series of castor oil derivatives. The castor derivatives included amides prepared by reaction
of castor oil with mono- or dialkanolamines, amides of ricinoleic acid with long chain di- and triamines, butanediol diricinoleate
and the commercial products-castor oil itself and the monoricinoleates of propylene glycol and pentaerythritol. Elastomers
were also prepared from commercial polyether diols for comparison. Properties evaluated include hardness, resilience, tear
strength, stress-strain properties, compression set and resistance to water and oil. Particularly high tensile and tear strengths
were obtained from the amides. Softer products with good properties were obtained from propylene glycol monoricinoleate and
from mixtures of the amides with castor oil or butanediol diricinoleate. Improved products were obtained by the use of diphenylmethane
diisocyanate in place of toluene diisocyanate.
Presented at the AOCS Meeting, Los Angeles, April 1972.
ARS, USDA. 相似文献
6.
New polyols of high hydroxyl content and reactivity were made from linseed and soybean oils and acids by catalytic carboxylation
followed by reaction with diethanolamine. Urethane foams made with these diethanolamides were stronger than those made with
castor oil at equivalent polyol wt. Because of their higher hydroxyl content, a larger amount of diethanolamides could be
incorporated in foam formulations than is possible with castor oil. The rigid urethane foams prepared with the new polyols
meet the requirements of commercial products with respect to density, compressive strength, and dimensional stability.
National Flaxseed Processors Association Fellow, 1969–1973. Present address: Avery Products, Technical Center, 325 North Altadena
Dr., Pasadena, CA 91107. 相似文献
7.
Foam stability and polymer phase morphology of flexible polyurethane foams synthesized from castor oil
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Chandan Sharma Sanjay Kumar A. Raman Unni Vinod K. Aswal Sangram K. Rath G. Harikrishnan 《应用聚合物科学杂志》2014,131(17)
Foam stability and segmented polymeric phase morphology of polyurethane foams synthesized partially and completely from castor oil are investigated. Preliminary analysis of the impact of alterations in the polymeric phase on macroscopic stress dissipation in foams is also carried out. The stability and morphology show unique trends depending on the concentration of castor oil used in foam synthesis. While low and intermediate concentrations of castor oil does not significantly affect the foaming process; at high concentrations, the volumetrically expanding liquid matrix remains in a nonequilibrium state during the entire foaming period, resulting in significant foam decay from top. This increases the final foam cell density and decreases the plateau border thickness at bottom. In the polymeric phase of castor oil based foams, the fraction of monodentate urea increases at the cost of non‐hydrogen bonded urea. These monodentate urea domains undergo flocculation in foams synthesized completely from castor oil, thus prominently modifying the segmented morphology. The glass transition temperature of soft segments of partially substituted foams shows moderate increase, with indications of phase mixing between the polyether and castor oil generated urethane domains. Foams synthesized entirely from castor oil have significant sol fraction due to unreacted oligomers. The microscopic alterations in polymeric phase reduce the elastic recovery of partially substituted castor oil foams compared to its viscous dissipation under an applied stress. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40668. 相似文献
8.
C. K. Lyon V. H. Garrett E. N. Frankel 《Journal of the American Oil Chemists' Society》1974,51(8):331-334
Castor, safflower, and oleic safflower oil derivatives with enhanced reactivity and hydroxyl group content were prepared by hydroformylation with a rhodium-triphenylphosphine catalyst, followed by hydrogenation. Rigid urethane foams prepared from these hydroxymethylated derivatives had excellent compressive strengths, closed cell contents, and dimensional stability. Best properties were obtained from hydroxymethylated polyol esters of castor acids. 相似文献
9.
C. K. Lyon Vilma H. Garrett L. A. Goldblatt 《Journal of the American Oil Chemists' Society》1962,39(1):69-71
The preparation of solvent-blown rigid urethane foams from low cost castor oil-polyol mixtures was investigated. Solutions
of triisopropanolamine, and of mixtures of triisopropanolamine and triethanolamine in castor oil, were used as the polyol component of these foams. Foams were prepared by reacting these
polyol mixtures, in the presence of catalyst, surfactant, and trichlorofluoromethane, with prepolymers prepared from toluenediisocyanate
and certain polyether polyols or mixtures of these polyether polyols with castor oil. The effect of polyol and prepolymer
composition and blowing agent concentration on such foam properties as density and compressive strength was investigated.
The properties of the castor oil-based foams were comparable to those of foams obtained from more costly polyols.
Presented at the Spring Meeting of the American Oil Chemists' Society, St. Louis, Missouri, May 1–3, 1961.
A laboratory of the Western Utilization Researchand Development Division, Agricultural Research Service, U. S. Department
of Agriculture. 相似文献
10.
Castor oil is the only major natural vegetable oil that contains a hydroxyl group and so it is widely used in many chemical industries, especially in the production of polyurethanes. In this work, castor oil was interesterified with jatropha oil and the product was subsequently reacted with toluene diisocyanate to obtain urethane alkyd. The prepared urethane alkyd was characterized and its properties were determined and compared with those of the conventional (glycerol/jatropha oil) and commercial urethane alkyds. The castor oil/jatropha oil-based urethane alkyd had a lower molecular weight and viscosity, a slightly lower hardness and greatly longer drying time than the conventional and commercial urethane alkyds, but otherwise the film properties were broadly similar, including being very flexible, with an excellent adhesion and high impact resistance. In addition, they also exhibited excellent resistance to water and acid. 相似文献
11.
G. M. Yenwo J. A. Manson J. Pulido L. H. Sperling Alfonso Conde Napolen Devia 《应用聚合物科学杂志》1977,21(6):1531-1541
Castor oil was polymerized and crosslinked with sulfur or diisocyanates to form the vulcanized and urethane derivatives, respectively. Both types were swollen with a plastic-forming monomer plus crosslinker, and a second polymerization was carried out in situ. Polyblends were also made by emulsion polymerization of styrene and methyl methacrylate employing hydrolyzed castor oil as the soap. In all three polymerizations, a wide range of compositions was obtained. The resulting interpenetrating polymer networks were characterized using electron microscopy, modulus–temperature measurements, and stress–strain analysis. The polystyrene phase size of the castor oil–urethane/polystyrene IPN was shown to decrease with increased crosslinking of the castor oil component and with increased polystyrene contents. The modulus–temperature study showed two distinct glass transitions in all cases, with evidence of significant mixing of the two components in many cases. The stress–strain results show that some of the IPN's behave as reinforced, highly extensible elastomers at low polystyrene levels, and a rubber-toughened plastics at high levels of polystyrene or crosslinking. 相似文献
12.
N. Devia-Manjarres A. Conde G. Yenwo J. Pulido J. A. Manson L. H. Sperling 《Polymer Engineering and Science》1977,17(5):294-299
Polystyrene Latexes were synthesized using sodium ricinoleate (the ehief saponification product of castor oil) as the surfactant. Later sulfur, more sodium ricinoleate, and sometimes castor oil were added, and the emulsion heated to a temperature where the sulfur vulcanized the castor oil products, making a semi-interpenetrating polymer network. Stress-strain studies showed the presence of a well developed yield point and high elongation for some samples, indicating considerable toughening for slow rates of strain. Electron microscopy revealed a complex two-phased morphology. Usually polystyrene was the continuous phase. The rubbery phase domain size depended upon the amount of castor oil products added lzod impact strengths showed only modest improvements; probably because of the high glass transition temperature of the castor oil vulcanizate. 相似文献
13.
Characterization and oxidative stability of enzymatically produced fish and canola oil-based structured lipids 总被引:1,自引:7,他引:1
Casimir C. Akoh Charment O. Moussata 《Journal of the American Oil Chemists' Society》2001,78(1):25-30
Two-kilogram quantities of structured lipids (SL) of menhaden fish and canola oils containing caprylic acids (8∶0) were produced
in a laboratory-scale packed-bed bioreactor by acidolysis catalyzed by an immobilized lipase, Lipozyme IM, from Rhizomucor miehei. SL were characterized and their oxidative stabilities investigated. The SL contained 29.5% 8∶0 for fish oil and 40.15 for
canola oil. Polyunsaturated fatty acids (PUFA) of fish oil remained unchanged after the modification while PUFA of canola
oil were reduced from 29.6 to 21.2%. Monoenes, especially 18∶1n−9, were completely replaced by 8∶0 in fish oil and reduced
from 61.9 to 34.7% in canola oil. Downstream processing of enzymatically produced SL led to loss in natural total tocopherol
contents of the fish and canola oils. The effects of antioxidants such as α-tocopherol (TOC), tert-butylhydroxyquinone (TBHQ), and combinations thereof on the oxidative stability of SL were investigated. SL were analyzed
for oxidative stability index, peroxide value, conjugated diene content, free fatty acid content, iodine value, saponification
number, and thiobarbituric acid value. Iodine value of unmodified fish oil (154.71) was reduced to 144.10 and that of canola
oil (114.49) to 97.27 after modification. The SN increased from 183.72 to 242.63 for fish oil and from 172.50 to 227.90 for
canola oil. TBHQ exhibited better antioxidant effects than TOC. A combination of TBHQ/TOC also proved to be an effective antioxidant
for SL. We suggest the addition of antioxidants to enzymatically produced and purified SL. 相似文献
14.
A. Ehrlich M. K. Smith T. C. Patton 《Journal of the American Oil Chemists' Society》1959,36(4):149-154
Summary A systematic investigation of some 21 castor polyols as base materials for preparing urethane foams was carried out. Prepolymers
were prepared both from individual castor polyols and from mixtures of them with an anhydrous castor oil. Foams formed from
these prepolymers were checked for shrinkage on cure, density, and modulus.
From the wide range of results obtained it is evident that castor polyols can serve as effective urethane components. Aside
from serving as major polyols for reaction with di-isocyanates, they can also be used as modifying polyols a) to speed up
prepolymer preparation, b) to adjust prepolymer viscosity to any required degree, c) to minimize loss of modulus on humid
aging, and as cross-linking centers with negligible loss of foam modulus. Details covering the preparation of a nonshrinking,
semi-rigid, light-weight urethane foam based on an 85% anhydrous castor oil/15% epoxidized castor oil mix are outlined in
the article.
Presented at the Spring Meeting, American Oil Chemists' Society, Memphis, Tenn., April 20–23, 1958. 相似文献
15.
Waste PET bottles were depolymerized by propylene glycol at a weight ratio of PET to propylene glycol of 37.5 : 62.5, using zinc acetate as a catalyst. The glycolyzed product, consisting of oligomeric diols with a number–average molecular weight range of 240–1107, was obtained. It was further reacted with palm oil and tolylene diisocyanate to obtain urethane oils at hydroxyl to isocyanate ratios from 1 : 1 to 1 : 0.8, with and without methanol acting as a blocking agent. It was found that all the synthesized urethane oils were yellowish transparent liquids of low molecular weights. A lower isocyanate content or the presence of a blocking agent resulted in higher viscosity, higher molecular weight, and shorter drying time. The films of all synthesized urethane oils exhibited good hardness, excellent flexibility, and high impact strength. They also showed excellent water resistance, good acid resistance but only fair alkali resistance. Moreover, these prepared urethane oils had better adhesion compared with those of the commercial urethane oil. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007 相似文献
16.
In this study a novel macromer technique has been described for the styrenation of triglyceride oils. Macromers were prepared through the interesterification of castor oil with linseed oil followed by esterification with acrylic acid. In this preparation various castor oil/linseed oil ratios were applied to obtain a macromer which gave a copolymer with good film properties after copolymerization with styrene. Macromers were styrenated at 100°C using benzoyl peroxide as an initiator. The styrenation leads to improved film properties with the related interesterification product although castor oil is a non‐drying oil. 相似文献
17.
Waste poly(ethylene terephthalate) (PET) bottles were glycolyzed by propylene glycol (PG) at a weight ratio of PET to PG of 37.5 : 62.5 using zinc acetate as a catalyst. The glycolyzed product, consisting of oligomeric diols with a number‐average molecular weight range of 458–844, was obtained. It was further reacted with soybean oil and toluene diisocyanate to obtain urethane oils at hydroxyl to isocyanate ratios from 1 : 1 to 1 : 0.7, with and without methanol acting as a blocking agent. All the synthesized urethane oils were yellowish, transparent, low‐viscosity liquids of low molecular weights. A lower diisocyanate content and the presence of a blocking agent resulted in higher viscosity, higher molecular weight, and shorter drying time. The films of all synthesized urethane oils exhibited good hardness and adhesion. They also showed excellent water and acid resistance but only fair alkali resistance. However, these prepared urethane oils had lower flexibility and poorer wear resistance compared to those of the commercial urethane oil. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3040–3045, 2004 相似文献
18.
Polyurethane networks from formiated soy polyols: Synthesis and mechanical characterization 总被引:1,自引:1,他引:0
Luciane?L.?Monteavaro Eduardo?O.?da?Silva Ana?Paula?O.?Costa Dimitrios?Samios Annelise?E.?Gerbase Cesar?L.?Petzhold
Polyurethanes can be prepared using polyols obtained from vegetable oils in natura, such as castor oil, or from functionalized vegetable oils, such as hydroxylated soybean oil. These polyurethanes have different
valuable properties, determined by their chemical composition and cross-linking density. In this study, soy epoxy polyols
with different OH contents were prepared through a one-step reaction using the method of in situ performic acid generation. Polyols with OH functionalities from 1.9 to 3.2 were reacted in bulk with different diisocyanates
at a NCO/OH molar ratio of 0.8 and 60°C for 24 h. Mechanical properties of the polyurethanes were determined by dynamic mechanical
thermal analysis, hardness (Shore A), and swelling measurements. Polymer networks with glass-transition temperatures (T
g
) from −13 to 48°C were obtained. We observed that the higher the OH functionality of the polyols, the higher the T
g
and cross-linking density of the polyurethane network. The influence of diisocyanate structure (rigid or flexible chain),
curing temperature, and curing reaction time on mechanical properties was also investigated. 相似文献
19.
Two-step chemoenzymatic synthesis of urethane oils has been studied. Initially, the partial esters were prepared by lipase-catalyzed
transesterification of soybean and linseed oils with n-butanol. Partial esters were further reacted with different diisocyanates
to obtain urethane oils. The composition of the partial esters was varied with reaction time in the transesterification step.
Among all the lipases, the lipozyme was found to be the most suitable lipase for the transesterification reaction, yielding
80–85%. All of the urethane oils were of low molecular weights irrespective of the type of oil used in their preparation.
Urethane oils, based on MDI, exhibited the best scratch resistance. All of the urethane oils showed good acid and alkali resistance
and excellent solvent resistance. These oils also satisfactorily passed the impact resistance and the flexibility tests.
Department of Chemistry, Vidyanagari, Mumbai-400 098, India. 相似文献
20.
N. G. Wagle 《Journal of the American Oil Chemists' Society》1978,55(6):547-548
Refined groundnut oils were autoxidized to varying degrees as indicated by the peroxide values. Some autoxidized oils gave
spots around the same Rf as that attributed to castor oil in the thin layer chromatography test prescribed by ISI. The molybdic acid test was negative. 相似文献