Availabeonineatwnwsciencedirect.con ScienceDirect NCE ELSEVIER Prog.Polm.Sci.31(2006983-1008 www.vicr.com/locate/ppoly Addition polymers from natural oils-A review Vinay Sharma,P.P.Kundu* Received 23 January 2006:received in revised form 14 September 2006:accepted 15 September 2006 Abstract Emerging technological knowledge is leading research into new ventures.One such is the conversion of natural oils to im pro sthe sour of polymeric raw mater polymers from natural ois.This review paper discusses the synthesis and characteriation of new polymers from diferent Keyrd Natural oil Dynamic mechanical analysis;Cross-inking Drying oi:Glass transition temperature Contents 1.Introduction 984 2.1.1. Unmodified soybean oil polymers Modified soybean oil polymers ers 252 Epoxidized linseed oil polymers Castor oil polymers.. Polymers from other oils.................................................... 3. 1006 References.... .1006 ing author.Tel:+91167283606:ax:+9116728365 E-mail address:ppk93@yahoo.com (P.P.Kundu). 0079-6700/S-see front ma
Prog. Polym. Sci. 31 (2006) 983–1008 Addition polymers from natural oils—A review Vinay Sharma, P.P. Kundu Department of Chemical Technology, Sant Longowal Institute of Engineering and Technology, Sangrur, Punjab 148106, India Received 23 January 2006; received in revised form 14 September 2006; accepted 15 September 2006 Abstract Emerging technological knowledge is leading research into new ventures. One such is the conversion of natural oils to polymers to augment the use of petroleum products as the source of polymeric raw materials. Natural oils, such as vegetable oils, now mainly used in the food industry, offer alternatives, and recent research has studied new routes of synthesis of polymers from natural oils. This review paper discusses the synthesis and characterization of new polymers from different natural oils such as soybean, corn, tung, linseed, castor, and fish oil. The effects of different levels of unsaturation in the natural oils and various types of catalysts and comonomers on the properties of copolymers are considered. r 2006 Elsevier Ltd. All rights reserved. Keywords: Natural oils; Dynamic mechanical analysis; Cross-linking; Polymerization; Drying oil; Glass transition temperature Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 984 2. Polymers from natural oils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 985 2.1. Soybean oil polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 985 2.1.1. Unmodified soybean oil polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 985 2.1.2. Modified soybean oil polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 992 2.2. Fish oil polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 994 2.3. Corn oil polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 995 2.4. Tung oil polymers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 996 2.5. Linseed oil polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 998 2.5.1. Natural linseed oil polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 998 2.5.2. Epoxidized linseed oil polymers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1002 2.6. Castor oil polymers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1003 2.7. Polymers from other oils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1004 3. Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1005 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1006 References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1006 ARTICLE IN PRESS www.elsevier.com/locate/ppolysci 0079-6700/$ - see front matter r 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.progpolymsci.2006.09.003 Corresponding author. Tel.: +91 16 7283606; fax: +91 16 7283657. E-mail address: ppk923@yahoo.com (P.P. Kundu).
984 V.Sharma.P.P.Kundu Prog.Polym.Sci.31 (2006)983-1008 1.Introduction poxies:It is apparent that on a mond epoxies with numerous le es of tion of resins and polymeric materials.to replaceor In addition to their application in the food industry augment the traditional petro-chemical based poly- triglyceride oils have been used for the production mers and resins.Natural oils such as linseed and of coatings.inks,plasticizers,lubricants and agro- tung oil have long found various uses in the paint chemicals [3-9].In general,drying oils (these can and varnishes industries.These oils have tradition polymerize in air to form a tough elastic lm)are ally been use organic er as resins o widely usec In these alt 0u出 the semi-drying o (the oil have also been used in polymerizations. s The mers obtat ped from natural Natural oils are tricglveeride esters of fatty acids oils are biopolymers in the sense that they are the general structure of which is shown in Fig.1. generated from renewable natural sources;they are Triglycerides comprise three fatty acids joined by a often biodegradable as well as non-toxic. glycerol center [1].Most of the common oil contains Some biopolymers obtained from natural oils are fatty acids tha 2 carbons in flexible and rubbery.Generally,they are prepared al polye number o with other e.g rated bac fatty acid chai -oleic acid chain linoleic acid chain linolenic acid chain nter.Reprinted with permission from Polymer2001 Table I Main fatty acid contents in different ois Fatty acid C:#DB]Canola oil Com oi Cottonseed oil Linseed oil Olive oil Soybean oil Tung oil Fish oi 180 86 853 10.0 18.2 183 8.8 0.7 56.6 0.6 7.8 0.99 3.9 4.5 3.9 6.6 28 4.6 3.6 "Fish oils tend to in a high double bond co example.the co
1. Introduction In recent years natural oils have attracted renewed attention as raw materials for the preparation of resins and polymeric materials, to replace or augment the traditional petro-chemical based polymers and resins. Natural oils such as linseed and tung oil have long found various uses in the paint and varnishes industries. These oils have traditionally been used in organic coatings either as resins or as a raw material for the preparation of resins. Soybean oil, safflower oil, sunflower oil and canola oil have also been used in polymerizations. Natural oils are tri-glyceride esters of fatty acids, the general structure of which is shown in Fig. 1. Triglycerides comprise three fatty acids joined by a glycerol center [1]. Most of the common oil contains fatty acids that vary from 14 to 22 carbons in length, with 1–3 double bonds. The fatty acid distribution of several common oils is shown in Table 1 [1]. In addition, there are some oils comprise fatty acids with other types of functionalities (e.g., epoxies, hydroxyls, cyclic groups and furanoid groups) [2]. It is apparent that on a molecular level, these oils are composed of many different types of triglyceride, with numerous levels of unsaturation. In addition to their application in the food industry, triglyceride oils have been used for the production of coatings, inks, plasticizers, lubricants and agrochemicals [3–9]. In general, drying oils (these can polymerize in air to form a tough elastic film) are the most widely used oils in these industries, although the semi-drying oils (these partially harden when exposed to air) also find use in some applications. The polymers obtained from natural oils are biopolymers in the sense that they are generated from renewable natural sources; they are often biodegradable as well as non-toxic. Some biopolymers obtained from natural oils are flexible and rubbery. Generally, they are prepared as cross-linked copolymers. Bacterial polyesters are obtained from a large number of bacteria when subjected to metabolic stress. The cross-linking process for unsaturated bacterial polyester is shown ARTICLE IN PRESS O O O O O O glycerol center oleic acid chain linoleic acid chain linolenic acid chain fatty acid chain three ester bonds Fig. 1. The triglyceride chain containing three fatty acid chains joined by a glycerol center. Reprinted with permission from Polymer 2001; 42: 1569 r Elsevier Science Ltd., [10]. Table 1 Main fatty acid contents in different oils Fatty acid [#C: #DB] Canola oil Corn oil Cottonseed oil Linseed oil Olive oil Soybean oil Tung oil Fish oily Palmitic 16:0 4.1 10.9 21.6 5.5 13.7 11.0 — — Stearic 18:0 1.8 2.0 2.6 3.5 2.5 4.0 4 — Oleic 18:1 60.9 25.4 18.6 19.1 71.1 23.4 8 18.20 Linoleic 18:2 21.0 59.6 54.4 15.3 10.0 53.3 4 1.10 Linolenic 18:3 8.8 1.2 0.7 56.6 0.6 7.8 — 0.99 a-elaeostearic acid — — — — — — — 84 — Average #DB/triglyceride. — 3.9 4.5 3.9 6.6 2.8 4.6 7.5 3.6 Reproduced with the permission from J Appl Polym Sci 2001; 82: 703 r John Wiley and Sons, Inc. [1]. #C stands for number of carbon atoms in chain and #DB stands for the number of double bonds in that chain. y Fish oils tend to contain a high double bond content; for example, the composition of a Norway fish oil examined in one study contained a fatty acid (ethyl ester) composition with 8.90% having no double bonds, 6.03% having four double bonds, 37.25% having EPA or DPA and 24.72% (DHA) having six double bonds [29]. 984 V. Sharma, P.P. Kundu / Prog. Polym. Sci. 31 (2006) 983–1008
V.Sharma.P.P.Kundu Prog.Polym.ScL.31(2006)983-1008 985 in Fig.2,describing the cross-linking of the with cyclohexane dicarboxylic acid.Scheme 2(b) unsaturated bacterial polyesters prepa red from shows the oligomerization with maleic acid,which soybean oily fatty acids.It is observed that cross- introduces more double bonds in the oligomers. linking occurs in at least two polyester chain double bonds.Scheme I describes the representative 2.Polymers from natural oils 2.1.Soybean oil polymers ctherate.Schem nodified acrylated epoxidized s bean oil (AESO) ed from s with reagents selected to stiffen the polymer chain. extensivelyinvestigated by Larock Scheme 2(a)shows the oligomerization of an AESO soybean oils are biodegradable vegetable oil,readily -CH- CH -CH-CH -3-0—H0 CH --0 with the permission from Polym 69 wwwCH-CHww modified initiato
in Fig. 2, describing the cross-linking of the unsaturated bacterial polyesters prepared from soybean oily fatty acids. It is observed that crosslinking occurs in at least two polyester chain double bonds. Scheme 1 describes the representative process of cationic copolymerization of the triglyceride oil with styrene and divinylbenzene in the presence of a modified boron trifluoride diethyl etherate. Scheme 2 shows the oligomerization of a modified acrylated epoxidized soybean oil (AESO) with reagents selected to stiffen the polymer chain. Scheme 2(a) shows the oligomerization of an AESO with cyclohexane dicarboxylic acid. Scheme 2(b) shows the oligomerization with maleic acid, which introduces more double bonds in the oligomers. 2. Polymers from natural oils 2.1. Soybean oil polymers 2.1.1. Unmodified soybean oil polymers Polymers derived from soybean oils have been extensively investigated by Larock et al. [10–15]; soybean oils are biodegradable vegetable oil, readily ARTICLE IN PRESS CH CH2 C O O CH CH2 C O O HC CH2 C O O CH CH2 C O O CH CH2 C O O CH CH2 C O O Fig. 2. The cross-linking process of bacterial polyester obtained from soybean oily fatty acids. Reprinted with the permission from Polym Bull 2001; 46: 393 r Springer-Verlag, Inc. [24]. CO2 CO2 CO2 CH CH CH CH CH CH + + m n H2 C O O C O CH CH C O C O CH2 CH HC CH CH CH CH2 CH CH2 CH m Scheme 1. The proposed process of cross-linking of natural oil with styrene and divinylbenzene in presence of modified initiator. Reprinted with the permission from J Appl Polym Sci 2003; 90: 1832 r Wiley Periodicals, Inc. [30]. V. Sharma, P.P. Kundu / Prog. Polym. Sci. 31 (2006) 983–1008 985
986 V.Sharma.P.P.Kundu/Prog.Polym.Sci.31(2006)983-1008 8 入入⑧入入 2.b t9e80ne。一 available in bulk;specification of soybean oils used various polymers. Cationic copolymerization of Larock group are reportec in regular soybean oil,low n o a trigly e struc. soybe The H NMR shown in Fig These makes them ideal monomers for the preparation of analysis (DMA).thermogravimetric analysis
available in bulk; specification of soybean oils used by the Larock group are reported in Table 2. Natural soybean oil possesses a triglyceride structure with highly unsaturated fatty acid side chains. The 1 H NMR spectra of some example oils are shown in Fig. 3. The unsaturation in these oils makes them ideal monomers for the preparation of various polymers. Cationic copolymerization of regular soybean oil, low saturated soybean oil or conjugated low saturated soybean oil with styrene and divinylbenzene leads to various copolymers. These copolymers have been characterized by various techniques, including dynamic mechanical analysis (DMA), thermogravimetric analysis ARTICLE IN PRESS Scheme 2. The modification of acrylated epoxidized soybean oil (AESO) shown using cyclohexane dicarboxylic anhydride or maleic anhydride. These AESOs were cured with styrene or other comonomers. Reprinted with the permission from J Appl Polym Sci 2001; 82: 707 r John Wiley and Sons, Inc. [1]. 986 V. Sharma, P.P. Kundu / Prog. Polym. Sci. 31 (2006) 983–1008
V.Sharma.P.P.Kundu Prog.Polym.Scl.31(2006)983-100 981 之ima时n al dteaihn ef op Soybean oil C==C Fatty acids" Type No.? C16.0 C180 C18:1 C18:2 C183 an oil 3品 Conjugated saturated soybean oil Conjugated 5.1 5.0 3.0 20.0 64.0 9.0 For example.C18:2 represent the fatty acid (ester)that possesses 18 carbons and 2 C==C bonds cu-C-and -CH-CC- 人人U 7.0 50 30 20 10 0. crpy t0m的DsO therma Th me anc of the sovbean oil with onon er initiated by bo on tri- reported in Table 3.The vield of the cross-linked fluoride diethyl etherate results in polymers rangir product depends on the concentration of the cross. from soft rubbers to hard thermosets,depending on linking agents,such as divinylbenzene.dicyclopen- the oil and the stoichiometry employed [10].It was tadiene.etc.As usual.cross-linking increases the found that the initiator was immiscible with these glass transition temperature of the polymer.Poly- mers from different soybean oils show was mo properties,and the on of soybean oil polymers c aeuedhravoh on trifluoride diethyl eth on o resulted in polymers with good mechanical proper. ties and thermal stability. extraction,with the results shown in Tables 4 and 5. It has been observed that the copolymerization of From these results.it was clear that the composition soybean oils with other comonomers results in a of the copolymer dictated the properties.For network.with a gelation time dependent on the example,the oily component of the copolymer
(TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and thermal mechanical analysis (TMA). Cationic polymerization of the soybean oil with divinylbenzene comonomer initiated by boron tri- fluoride diethyl etherate results in polymers ranging from soft rubbers to hard thermosets, depending on the oil and the stoichiometry employed [10]. It was found that the initiator was immiscible with these oils, but that miscibility was vastly improved when the initiator was modified with a norway fish oil ethyl ester. The copolymerization of soybean oil with styrene and norbornadiene or dicyclopentadiene initiated by boron trifluoride diethyl etherate resulted in polymers with good mechanical properties and thermal stability. It has been observed that the copolymerization of soybean oils with other comonomers results in a network, with a gelation time dependent on the stoichiometry and type of the triglyceride oil used [11]. The gelation time and yield for various copolymers prepared from varying concentrations of the oils, comonomers and modified initiators is reported in Table 3. The yield of the cross-linked product depends on the concentration of the crosslinking agents, such as divinylbenzene, dicyclopentadiene, etc. As usual, cross-linking increases the glass transition temperature of the polymer. Polymers from different soybean oils show different properties, and the cross-linking density of the bulk polymers considerably affected their thermophysical properties [12]. Several copolymers obtained from copolymerization of a soybean oil with divinylbenzene were characterized by DMA, TGA and soxhlet extraction, with the results shown in Tables 4 and 5. From these results, it was clear that the composition of the copolymer dictated the properties. For example, the oily component of the copolymer ARTICLE IN PRESS Fig. 3. The 1 H NMR spectra of different soybean oils. (a) regular soybean oil, (b) low saturated soybean oil and (c) conjugated low saturated soybean oil. Reprinted with permission from J Appl Polym Sci 2001; 80: 660 r John Wiley and Sons, Inc. [11]. Table 2 The composition of the soybean oils used for the preparation of copolymers Soybean oil CQQC Fatty acidsb Type No.a C16:0 C18:0 C18:1 C18:2 C18:3 Regular soybean oil Non-conjugated 4.5 10.5 3.2 22.3 54.4 8.3 Low saturated soybean oil Non-conjugated 5.1 5.0 3.0 20.0 64.0 9.0 Conjugated saturated soybean oil Conjugated 5.1 5.0 3.0 20.0 64.0 9.0 Reproduced with the permission from J Polym Sci: Part B: Polym Phys 2000; 38: 2722 r John Wiley and Sons, Inc. [12]. a The average number of carbon-carbon double bonds was calculated by 1 H NMR spectral analysis. b For example, C18:2 represent the fatty acid (ester) that possesses 18 carbons and 2 CQQC bonds. V. Sharma, P.P. Kundu / Prog. Polym. Sci. 31 (2006) 983–1008 987