Polymerization of 2-allyl-1-methylenecyclohexane by the cyclic polymerization mechanism

2-Ally-1-methylenecyclohexane is a compound which is functionally capable of undergoing polymerization by the alternating intra-intermolecular propagation mechanism to produce poly[1,8-methylene[4.3.0] bicyclononane]. This monomer was synthesized and its polymerization through use of cationic and Ziegler-type initiators was studied. Synthesis of the monomer was accomplished by the following reaction sequence: (1) conversion of cyclohexanone to 2-allycyelohexanone by reaction wtih allyl bromide and sodium amide and (2) conversion of 2-allycyclohexanone to the desired monomer by reaction with the phosphorane derived from methyltriphenylphosphonium bromide. Polymerizaton was accomplished by use of boron trifluoride resulting in 44% conversion to polymer, of which 94% was soluble. Through use of infrared and nuclear magnetic resonance techniques, the soluble portion of the polymer was shown to contain 54% of bicyclic units and the remainder to be non-cyelized monomer units in which the residual unsaturation was composed predominantly of allyl groups.     

Allyl esters and allyl epoxy esters from crambe oil

Room temperature transesterification of crambe oil with allyl alcohol gave allyl esters previously prepared by hydrolysis of the oil and reesterification of the mixed acids at elevated temperatures. Treating the esters with m-chloroperbenzoic acid in the presence of sodium bicarbonate resulted in the selective epoxidation of ethylenic bonds and suppression of side reactions. Bifunctional allyl epoxy esters produced in 88% overall yield by this method contain 5.08% oxirane oxygen and an unsaturation equivalent to 91% allyl group; they are prospective monomers for various types of polymerization.     

The Copolymerisation of Vinyl Chloride with Allyl Chloride

The kinetics of copolymerisation of vinyl chloride with allyl chloride in chlorobenzene and in dichloroethane solvent have been studied by a dilatometric method. The compositon of the copolymers was determined by reduction with tributyltin hydride followed by infrared examination. Molecular weights obtained by g.p.c. enable as estimate of the transfer constant for degradative transfer to allyl chloride to be made for both the chlorobenzene and dichloroethane solvent systems. The results show that allyl chloride retards vinyl chloride polymerisation by degradative transfer and that the resulting radicals combine with the growing polymer chains. The dependence of copolymer composition on the composition of the monomer feed reveals that one of the pair of reactivity ratios associated with this reaction in either solvent has a negative value.     

Radiation induced ionic polymerisation and grafting of vinyl monomers

Some special aspects of the radiation induced ionic polymerisation and grafting of vinyl monomers will be described. In particular the effects of solvents on the cationic polymerisation of the vinyl ethers will be discussed in detail. The unequivocal free ion nature of the polymerisation makes such information of considerable general interest. Estimates of the propagation rate constants with free cation polymerisation in solvents of different dietectric constants and solvation powers will be presented. Finally, some observations on the radiation induced graft polymerisation of ethyl vinyl ether to poly (vinyl chloride) and to polypropylene will be presented.     

Emulsion Polymerisation of Styrene and Vinyl Acetate

Kinetic data on the emulsion polymerisation of styrene are discussed in the light of the Smith-Ewart theory as modified by Gardon. It is shown that at least in the beginning of the reaction serious discrepances exist between experimental results and the theoretical concept. An electrolytic effect in cationic emulsifier systems was found. Emulsion polymerisation of vinyl acetate was investigated and the mechanism is discussed. The polymerisation of vinyl acetate in aqueous solution without added emulsifier begins as a true solution polymerisation but very soon changes to a suspension polymerisation. The latex particles formed are an order of magnitude larger than those obtained in the emulsion polymerisation and have a very narrow size distribution. There seems to be a very short period of particle formation in this system.     

Ionically conducting networks derived from PEO containing aziridine groups

Aziridine‐modified poly(ethylene oxide)s (PEOs) were obtained via 1,3‐dipolar addition of α,ω‐unsaturated PEO onto 3,3′‐diazidodiphenyl sulfone. The unsaturated telechelic functions used were allyl and methacrylate. To establish the structure of the condensation products, unsaturated model compounds of low molecular weight were also reacted with the same azide. The formation of a mixture of aziridine and triazoline functionalized compounds was proved when the unsaturation was of allylic type. Only aziridine function was detected in the case of methacrylate‐type unsaturation. The polymers containing aziridine functions were crosslinked by cationic ring opening polymerization of the aziridine units. The introduction of nitrogen‐containing heterocycles into the poly(ethylene oxide) backbone and their transformation into amine bridges induced an increase of the glass transition temperature (Tg) of the modified linear and crosslinked polymers as compared to the unmodified PEOs. Reciprocal Tg was shown to increase linearly when lithium trifluoromethanesulfone imide was introduced into the networks. Conductivity measurements were carried out and a maximum ionic conductivity of 6.10⁻⁶Scm⁻¹ at O/Li = 20 at room temperature was achieved. © 1999 Society of Chemical Industry     

Rapid polymerisation and cross-linking reactions in thin film (1) the stopped-flow rotational viscometer: Construction and preliminary studies

The design and construction of a stopped flow rotational viscometer is described. This novel technique enables rapid polymerisation reactions in thin films to be studied in a controlled environment over a range of temperatures. The apparatus enables two components of a polymerisation system (typically monomer/solvent and initiator/solvent) to be separately and rapidly delivered to the sample cavity of a cone and plate viscometer. The flow of the components can be simultaneously arrested and the viscosity of the resultant monomer/initiator/solvent mixture monitored as a function of time. The system was designed for the study of cyclo olefin-based polymerisation and cross-linking reactions in the development of metal coating systems capable of high cross-linking rates. An initial evaluation was however carried out using the well characterised free radical polymerisation of styrene and the cationic polymerisation of styrene catalysed by boron trifluoride etherate in toluene.     

Radiation-induced and electroinitiated polymerisation of 1, 2-Epoxy-4-epoxyethylcyclohexane

Liquid state radiation-induced and electroinitiated cationic polymerisation of 1,2-epoxy-4-epoxyethylcyclohexane (EECH) have been investigated. Soluble and cross-linked polymers were obtained during the radiation-induced polymerisation of EECH, depending upon the radiation dose. Electroinitiated polymerisation of the monomer yielded cross-linked polymers on the surface of the anode. The expected polyether structure was observed for i.r. data. The polymerisation propagates via opening of the epoxy rings as indicated by n.m.r. spectra. X-Ray analyses showed that the products obtained by both methods are amorphous.     

Diacetoxyiodobenzene and bis(trifluoroacetoxy)iodobenzene as photoinitiators for cationic polymerisations

Summary It is shown that i-butyl vinyl ether, tetrahydrofuran, epichlorhydrin and cyclohexene oxide, which undergo typically cationic polymerisation, are polymerised by UV-irradiation in the presence of diacetoxyiodobenzene or bis(trifluoroacetoxy)iodobenzene.     

Effect of chemical structure of allyl ethers on polymerization and properties of multifunctional acrylate systems

Allyl ether resins with various chemical structures and degrees of functionality were used as promoters and cross-linkers for polymerization of acrylic oligomers at room temperature in air. Thin films were prepared to allow monitoring of polymerization via disappearance of acrylate and allylic unsaturation by FTIR. The effect of air upon curing of films was investigated; excluding air from the surface of the film had a much greater effect than did addition of allyl ether. In air, the curing rate and extent of cure were found to be dependent upon molecular weight M_n and degree of functionality of the allyl compounds. At high allyl monomer concentrations, homopolymerization of the allyl groups occurred. The mechanical properties (tensile strength, Young's modulus, and elongation at break) of films were evaluated on an Instron, whereas viscoelastic properties, transition temperatures, and cross-link densities of polymer bars were studied by dynamic mechanical analysis and relaxation measurements. The study showed that addition of highly functional allyl ethers combines the advantages of an air-curable system with those of highly cross-linked materials, allowing ultimate properties to be tailored.     

Influence of moisture on the photochemically induced polymerisation of epoxy groups in different chemical environment

The influence of atmospheric humidity on the photochemically induced cationic polymerisation of epoxy groups in different chemical environments is shown. With increasing humidity, the polymerisation rate of glycidylethers decreases, whereas for epoxides with endocyclic epoxy groups the rate of polymerisation increases and the rate for epoxides with exocyclic epoxy groups is nearly not influenced. The reasons for the different behaviour are energetic differences for the reactions between the positively charged chain ends with water and the following proton transfer. Furthermore the reaction rate is influenced by the different stereochemistry of the attack of the next monomer.     

Alkyd Resins from Polymerised Rubberseed Oil

Abstract

Rubberseed oil (RSO) was thermally polymerised at different temperatures. It was also polymerised at the same temperature using various percentage of benzoyl peroxide (BPO) and Azobisisobutyronitrile (AIBN) as free radical catalysts. During polymerisation, the free fatty acid content increased as revealed by increasing acid value and unsaturation decreased as indicated by decreasing iodine value. The FFA, unsaturation, viscosity and refractive index of the polymerised oil samples were determined.

Alkyd resins were prepared from as it is and polymerised rubberseed oil samples. The physical properties and air dried and baked film properties of these alkyd resins were studied and compared.     

Effect of allylic halides on catiomic polymerization of 1,3-pentadiene

Summary The cationic polymerization of 1,3-pentadiene (PD) initiated by AlCl₃ in n-hexane was carried out in the presence of allylic halides, i.e., 3-chloro-1-butene, allyl chloride, and allyl bromide. All these allylic halides strongly hindered crosslinking which is a major side reaction during PD cationic polymerization. Cyclization, another side reaction, was also reduced by the addition of the allylic halides. The influences of these halides on polymer yields and molecular weights are also discussed.     

Molecular weight distribution of fractionated poly (hexamethylene Oxide)

Poly(hexamethylene oxide) obtained by two routes, polycondensation and cationic polymerisation, is fractionated and its molecular weight distribution is analysed by using well known data treatment methods namely those of Beall, Wesslau, Tung and Saiz and Horta. The results are compared and discussed showing that the polycondensated sample has a lower molecular weight and wider distribution than the cationic one.     

Simultaneous construction of polymer backbone and side chains by terpolymerization. Synthesis of polyethers with the allyl side chains from dialdehydes, alkylene bis(trimethylsilyl) ethers, and allyltrimethylsilane

Polyethers with allyl side chains were synthesized by the simultaneous acid-catalyzed reaction of dialdehydes (1), alkylene bis(trimethylsilyl) ethers (2), and allyltrimethylsilane (3). The reactions of 1, 2 and 3 were carried out in the presence of 10 mol% of triphenylmethyl (trityl) perchlorate at −55°C to yield polyethers having allyl groups in the side chains. When the dialdehyde having the ester moieties as 1, ethylene bis(trimethylsilyl) ether and 1,4-bis(trimethylsiloxy)cyclohexane as 2 were used, high molecular weight polymers were obtained. In the polymerizations at ambient temperature, the polymer was precipitated during the reaction because of crosslinking between the aromatic rings via a trityl perchlorate assisted Friedel-Crafts reaction. The soluble polyether with the allyl side chains reacted with 1,2-ethanedithiol in the presence of a radical initiator in benzene at 60°C to yield a crosslinked polymer quantitatively within 1 h. This polymer synthesis is unusual in that it concurrently constructs both the polymer backbone and the functional side chains from three monomers.     

The influence of poly(vinyl alcohol) suspending agents on suspension poly(vinyl chloride) morphology

The requirements for PVC suspension resin have changed considerably in the last few years, so much so that few companies have products on their ranges that are more than 4 or 5 years old. The suspending agent has a crucial influence on the morphology of the resin, so the changes in resin characteristics have largely been achieved by changes in the suspending agent systems. After a brief review of the mechanism of PVC suspension polymerisation, the properties of polymers made using PVOH suspending agents are related to changes in the latter. The effect of variations in PVAc degree of hydrolysis and viscosity are related to changes in surface tension. Methods of achieving higher porosity by using low hydrolysis co-suspending agents are described. It is shown that higher bulk densities can be achieved by delayed addition of the PVOH. Levels of conjugated unsaturation and copolymer distributions are also shown to have important influences.     

Epoxy coatings containing clays and organoclays: Effect of the filler and its water content on the UV-curing process

UV-cured coatings were prepared by photoinitiated cationic ring-opening polymerisation of epoxides in the presence of natural montmorillonite and different organically modified clays (5 wt%). The curing was monitored by FTIR in real time while irradiating the formulations by UV light. Significant changes of both the rate of curing and the final conversion were found. Only in the presence of a suitable montmorillonite and after a suitable pre-treatment, the process showed the same polymerisation rate, guaranteed a higher conversion than the neat epoxide and the formation of intercalated nanostructured coatings.     

二苯基碘鎓氟硼酸盐引发AGE阳离子光聚合与光交联的研究

用合成的二苯基碘钅翁氟硼酸盐作为光敏引发剂 ,研究了含乙烯基和环氧基两种不同官能基的烯丙基缩水甘油醚 ( AGE)的阳离子光聚合和聚合前后微观结构的变化 ,讨论了其阳离子光聚合的特征和机理 ,测定了光聚合引起光交联的凝胶转化率曲线     

Synthesis and photo‐curing behaviors of silicon‐containing (vinyl ether)–(allyl ether) hybrid monomers

A series of silicon‐containing (vinyl ether)–(allyl ether) hybrid monomers used in nano‐imprint lithography resists were synthesized and subjected to photo‐initiated polymerization. The surface energies of the monomers and the resulting polymer films were then investigated. The surface energies of the monomers were very low at less than 15 mJ m^–2. The photo‐curing behaviors of the five hybrid monomers were investigated using real‐time Fourier transform infrared spectroscopy. The monomers were sequentially initiated with cationic (PAG201) and mixed (cationic initiator PAG201, radical initiator ITX or TPO) initiators. The vinyl ether double bond polymerized both rapidly and completely, whereas the allyl ether double bond remained when PAG201 was used as the photo‐initiator and polymerized completely with mixed initiators. The different double bonds of the silicon‐containing (vinyl ether)–(allyl ether) hybrid monomer increased the efficiency of the polymerization and overcame the intrinsic limitations of the free radical and cationic polymerization processes, including strong oxygen inhibition, large volume shrinkage and high humidity sensitivity. The five monomers with low viscosity, low surface energy, good thermal stability and good photo‐polymerization properties were suitable for nano‐imprint photoresists. © 2013 Society of Chemical Industry     

二苯基碘(钅翁)氟硼酸盐引发AGE阳离子光聚合与光交联的研究

用合成的二苯基碘(钅翁)氟硼酸盐作为光敏引发剂,研究了含乙烯基和环氧基两种不同官能基的烯丙基缩水甘油醚(AGE)的阳离子光聚合和聚合前后微观结构的变化,讨论了其阳离子光聚合的特征和机理,测定了光聚合引起光交联的凝胶转化率曲线.