Saponification Treatment Research Articles

Strategies and mechanisms for improving the detection accuracy of nonextractable residues of polycyclic aromatic hydrocarbons in soils

The methods that can accurately measure the concentrations of nonextractable residues (NERs) of hydrophobic organic contaminants (HOCs) in soil are still lacked in current studies. In this study, three methods, namely methanolic saponification treatment (MST), silylation treatment (ST), and acid deashing treatment (ADT), were investigated and then combined to extract the NERs of six types of polycyclic aromatic hydrocarbons (PAHs) from nine soil samples. The NER concentrations of PAHs obtained by ST (2.43–521.73 ng g−1) were comparable to or significantly higher than those obtained by MST (1.94–291.54 ng g−1), owing to the properties of soil and target compounds. Additionally, ADT could further release a considerable amount of PAH NERs (0.39–276.99 ng g−1) from the soils that had been treated with ST. The mechanism was that acid solution dissolved mineral components, significantly increasing the pore size of the soil matrices from 9.37–15.57 nm to 17.11–27.51 nm. The average percentage of each PAH obtained by ADT (the ratio of the amount obtained by ADT to the total NER content) exhibited a negative correlation with their ring numbers (R2 = 0.62, p < 0.05), whereas the percentage of targets recovered through ST increased linearly with their log KOW values (R2 = 0.75, p < 0.05). Moreover, there is a positive correlation (R2 = 0.73, p < 0.05) between the NER percentages of phenanthrene (obtained by ST–ADT) and the specific surface areas of soils, and the NER percentages of benzo(g,h,i)perylene is positively correlated to the content of total organic carbon (R2 = 0.62, p < 0.05). These results suggested that the amounts and locations of NERs were influenced by both the physicochemical characteristics of PAHs and soils. These findings provide some basic understandings of the entrapped mechanisms of PAH NERs, helping to establish strategies for improving their detection accuracy.

A Novel Fabrication of Heterogeneous Saponified Poly(Vinyl Alcohol)/Pullulan Blend Film for Improved Wound Healing Application.

In this study, a novel film of poly(vinyl alcohol) (PVA)/pullulan (PULL) with improved surface characteristics was prepared from poly(vinyl acetate) (PVAc)/PULL blend films with various mass ratios after the saponification treatment in a heterogeneous medium. According to proton nuclear magnetic resonance (1H-NMR), Fourier transform infrared, and X-ray diffraction results, it was established that the successful fabrication of saponified PVA/PULL (100/0, 90/10, and 80/20) films could be obtained from PVAc/PULL (100/0, 90/10, and 80/20) films, respectively, after 72 h saponification at 50 °C. The degree of saponification calculated from 1H-NMR analysis results showed that fully saponified PVA was obtained from all studied films. Improved hydrophilic characteristics of the saponified films were revealed by a water contact angle test. Moreover, the saponified films showed improved mechanical behavior, and the micrographs of saponified films showed higher surface roughness than the unsaponified films. This kind of saponified film can be widely used for biomedical applications. Moreover, the reported saponified film dressing extended the lifespan of dressing as determined by its self-healing capacity and considerably advanced in vivo wound-healing development, which was attributed to its multifunctional characteristics, meaning that saponified film dressings are promising candidates for full-thickness skin wound healing.

Targeting greens and yellows: A solar biorefinery analysis for the microalgae-based co-production of pigments, proteins, and fuel

Microalgae biorefineries can enable cost effective cascaded biomass use to produce multiple product and revenue streams (e.g., protein-rich foods & feeds, pigments, biomaterials and high-density liquid fuels). The aim of this work is to develop a multi-product microalgae biorefinery simulation that employs a green chemistry-based alkaline saponification treatment to extract proteins, chlorophyllins, and lutein from microalgal (Chlorella sp.) biomass and subject it to techno-economic evaluation for a 50-ha facility. Optimisation of the saponification parameters revealed that the most value-generating strategy is a sequential saponification in which the biomass is first treated at mild conditions (0.4 % NaOH, 45 °C, 0.5 h) to recover a high quality protein fraction (with a calculated extraction efficiency of 42.5 %), followed by a harsher treatment (4 % NaOH, 70 °C, 8.5 h) to extract carotenoids and recover chlorophyllins for the synthesis of copper chlorophyllin. Water-insoluble chlorophylls are usually not refined, but their water-soluble and stable copper chlorophyllin derivatives offer significant utility for materials science, nutrition, and biomedicine. The obtained protein fraction has a purity of 44 %. It contains high molecular weight proteins and has a relatively unchanged amino acid composition, making it competitive with common plant-based protein meals on the market. The purities of the obtained carotenoid (mainly lutein) and the copper chlorophyllin fractions are estimated to be 5.47 % and 10.9–13.6 %, respectively. The process also produced a low-nitrogen fuel feedstock that can be converted into renewable diesel using hydrothermal liquefaction. The techno-economic analysis results show that at a 10 % internal rate of return (IRR) competitive bioproduct valuation (7 US$·kg−1 for 5 % lutein, 16 US$·kg−1 for 10 % Cu-chlorophyllin, 3.28 US$·kg−1 for 44 % protein, and US$0.67 L−1 for renewable diesel) can be achieved, which shows promise for saponification as a major biomass fractionation process. Multi-product microalgae biorefineries will help achieve a circular bioeconomy.

Preparation of the Heterogeneous Saponified Poly(Vinyl Alcohol)/Poly(Methyl Methacrylate-Methallyl Alcohol) Blend Film.

For the first time, poly(vinyl alcohol) (PVA)/poly(methyl methacrylate–methallyl alcohol) (P(MMA-MAA)) (9:1, 7:3, 5:5) blend films were made simultaneously using the saponification method in a heterogeneous medium from poly(vinyl acetate) (PVAc)/poly(methyl methacrylate) (PMMA) (9:1, 7:3, 5:5) blend films, respectively. The surface morphology and characteristics of the films were investigated using optical microscopy (OM), atomic force microscopy (AFM), X-ray diffractometer (XRD), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Moreover, the effect of the PVAc content on the degree of saponification (DS) of the PVAc/PMMA films were evaluated and revealed that the obtained DS value increased with the increase in PVAc content in the PVAc/PMMA blend films. According to the OM results, the saponified films demonstrated increased surface roughness compared with the unsaponified films. The AFM images revealed morphological variation among the saponified PVAc/PMMA blend films with different mass ratios of 9:1, 7:3, and 5:5. According to the DSC and TGA results, all blend film types exhibited higher thermal property after the saponification treatment. The XRD and FTIR results confirmed the conversion of the PVAc/PMMA into PVA/P(MMA-MAA) films. Thus, our present work may give a new idea for making blend film as promising medical material with significant surface properties based on hydrophilic/hydrophobic strategy.

Tissue Microarrays to Visualize Influenza D Attachment to Host Receptors in the Respiratory Tract of Farm Animals.

The trimeric hemagglutinin-esterase fusion protein (HEF) of influenza D virus (IDV) binds 9-O-acetylated sialic acid receptors, which are expressed in various host species. While cattle are the main reservoir for IDV, the viral genome has also been detected in domestic pigs. In addition, antibodies against IDV have been detected in other farm animals such as sheep, goats, and horses, and even in farmers working with IDV positive animals. Viruses belonging to various IDV clades circulate, but little is known about their differences in host and tissue tropism. Here we used recombinantly produced HEF proteins (HEF S57A) from the major clades D/Oklahoma (D/OK) and D/Oklahoma/660 (D/660) to study their host and tissue tropism and receptor interactions. To this end, we developed tissue microarrays (TMA) composed of respiratory tissues from various farm animals including cattle, domestic pigs, sheep, goats, and horses. Protein histochemical staining of farm animal respiratory tissue-microarrays with HEF proteins showed that cattle have receptors present over the entire respiratory tract while receptors are only present in the nasal and pharyngeal epithelium of pigs, sheep, goats, and horses. No differences in tropism for tissues and animals were observed between clades, while hemagglutination assays showed that D/OK has a 2-fold higher binding affinity than D/660 for receptors on red blood cells. The removal of O-acetylation from receptors via saponification treatment confirmed that receptor-binding of both clades was dependent on O-acetylated sialic acids.

Impact of non-rubber components on the branching structure and the accelerated storage hardening in Hevea rubber

Natural rubber (NR) contains cis-1,4-polyisoprene as well as a small quantity of non-rubber components, affecting the physical properties of NR, especially the storage hardening via gel formation. The free and/or linked non-rubber components were removed from NR by various treatments. The origin of gel formation in NR mainly resulted from proteins, which could be removed by enzymatic deproteinisation, surfactant washing or saponification treatment, and partly from phospholipids linked to NR molecule via H-bonding, which were decomposed by saponification or polar solvent treatment. The effect of the non-rubber components in NR on storage hardening was investigated by an accelerated storage hardening test (ASHT). The crude NR (CNR) containing proteins and lipids clearly showed the increase of gel content, suggesting the formation of crosslink structure during storage, resulting in the high plasticity number and Mooney viscosity after the ASHT. The gel content in protein-free NR did not change significantly only in washed NR (WSNR), but increased in the enzymatic deproteinised NR (DPNR). This resulted from the presence of residual proteins, such as oligopeptides. Interestingly, the gel content also reduced in the acetone extracted CNR (AE-CNR) and there was no significant effect on the storage hardening after ASHT, like WSNR. These were supposed to be due to the interaction or the participation of proteins and free fatty acids in the branching formation. Although the saponification could be decomposed branching at both terminal ends of the NR molecule, the protein and lipid residues occluded in the saponified NR (SPNR) affected the storage hardening. However, the flocculant remaining in the SPNR coagulated with acid and flocculant (AF-SPNR) would obstruct both gel formation and storage hardening.

Chemical composition of lipophilic extractives from six Eucalyptus barks

Barks show a large diversity in chemical composition and are generally characterized by a substantial content of extractives. Today, these components are viewed with a renewed interest as valuable source of chemicals and bioactive compounds. The barks of six eucalypt species, Eucalyptus botryoides, E. camaldulensis, E. maculata, E. rudis, E. sideroxylon and E. viminalis, were studied in relation to their lipophilic extractives that represented between 0.1% (E. rudis) and 1.8% (E. viminalis) of the oven-dry bark. It is the first time that a detailed chemical composition is given for the lipophilic extracts from the barks of these eucalypt species. They showed a high content in triterpenes (between 3623.1 and 13,616.5 mg/kg of bark), especially triterpenic acids such as betulinic, ursolic, oleanolic and arjunolic acids. Sterols were also identified in considerable amounts (174.0–1736.7 mg/kg of bark). β-Sitosterol was the major sterol, with 1350.1 mg/kg of bark in E. maculata. Fatty acids C16–C28 existed in smaller amounts. A saponification treatment (MeOH/KOH) showed that fatty acids, sterols and triterpenes existed in both esterified and non-esterified forms. The presence of triterpenes represents a potential added value for the valorization of bark residues by production of bioactive or high-value compounds.

A Non-Enzymatic Pathway with Superoxide in Intracellular Terpenoid Synthesis.

Non-C5 -units terpenoids (norisoprenoids) with an acetonyl group are widely distributed in nature. However, studies on the biosynthesis of norisoprenoids are scarce. Now, the C33 norisoprenoid, (all-E)-farnesylfarnesylacetone, was identified from Bacillus spp. and it was elucidated for the first time that superoxide mediates the cleavage of menaquinones (vitamin K) to form norisoprenoids in saponification treatment. From in vivo experiments using gene-disrupted Bacillus subtilis strains targeted for enzymes responsible for menaquinone biosynthesis and for superoxide dismutase, it was suggested that the non-enzymatic cleavage (autoxidation) of menaquinone with superoxide resulted in norisoprenoid synthesis in Bacillus cells. Furthermore, the bioactive norisoprenoids, farnesylacetone and phytone, were produced in Bacillus cells by this novel synthesis system.

A Non‐Enzymatic Pathway with Superoxide in Intracellular Terpenoid Synthesis

AbstractNon‐C5‐units terpenoids (norisoprenoids) with an acetonyl group are widely distributed in nature. However, studies on the biosynthesis of norisoprenoids are scarce. Now, the C33 norisoprenoid, (all‐E)‐farnesylfarnesylacetone, was identified from Bacillus spp. and it was elucidated for the first time that superoxide mediates the cleavage of menaquinones (vitamin K) to form norisoprenoids in saponification treatment. From in vivo experiments using gene‐disrupted Bacillus subtilis strains targeted for enzymes responsible for menaquinone biosynthesis and for superoxide dismutase, it was suggested that the non‐enzymatic cleavage (autoxidation) of menaquinone with superoxide resulted in norisoprenoid synthesis in Bacillus cells. Furthermore, the bioactive norisoprenoids, farnesylacetone and phytone, were produced in Bacillus cells by this novel synthesis system.

Rheological Behavior Characterization of Natural Rubber Containing Different Gel

This research, natural rubber containing different gel contents were prepared by deproteinization and saponification treatment from high ammonium natural rubber latex. Deproteinization natural rubber was further treated as acetone extraction and then transesterification. It was founded that gel content and molecular weights of treated natural rubber were decreased and almost absented for transesterification treatment. Rheological respond on small amplitude oscillating shear (SAOS) and large amplitude oscillating shear (LAOS) deformation of treated natural rubber were captured by using rubber process analyzer (RPA 2000). Firs harmonic rheological properties, storage modulus, G and loss modulus, G decreased as gel content and molecular weight decreased. It was believed that gels, explicitly branching points, were destroyed after the natural rubber was deproteinized, transesterification, or saponification according to the molecular structure of natural rubber presumed by Tanaka et al, which functional groups contain protein and fatty acid are participated in branching to forming gel structure. It was concluded that gel content as the same as molecular structure of natural rubber could be characterized as rheological behavior.

Recovery of solanesol from tobacco as a value-added byproduct for alternative applications

Solanesol in the waste streams of a bioprocess designed for alternative applications of low-alkaloid tobacco was recovered using three different extraction methods. Compared to the conventional heat-reflux extraction (HRE) and ultrasound-assisted extraction (UAE), microwave-assisted extraction (MAE) using 1:3 hexane:ethanol (v/v) as the solvent after saponification treatment of tobacco biomass was found the most effective in terms of solanesol yield, processing time, and volume of solvent consumed. Quantification of solanesol was achieved by optimizing the mobile phase at 60/40 acetonitrile–isopropanol and lowering the oven temperature to 22 °C using a standard reverse-phase high performance liquid chromatography (RP-HPLC). The total solanesol recovered from tobacco biomass and chloroplast accounted for 30% (w/w) of the total solanesol in the fresh leaves. Since solanesol is the precursor of metabolically active quinones such as coenzyme Q10 and vitamin K analogues, extraction of solanesol from tobacco bioprocess waste is a feasible operation and could leverage the overall profitability of biorefining tobacco for alternative, value-added uses.

Analysis of Glomerular Anionic Charge Status in Children with IgA Nephropathy Using Confocal Laser Scanning Microscopy

Background: The proteinuria resulting from IgA nephropathy is secondary to altered charge-selective and/or size-selective properties of the glomerular capillary walls. However, the functional changes occurring within the glomerular capillary network which lead to proteinuria are still poorly understood. In this study, we analyzed the participation of charged components in the glomerular capillary and their role with respect to proteinuria in childhood IgA nephropathy. Methods: We examined glomerular anionic charge in renal biopsy specimens with confocal laser scanning microscopy using FITC-conjugated poly-L-lysine as a cationic tracer. The renal specimens investigated were from 9 children with IgA nephropathy (IgAN(+)) associated with detectable proteinuria in a morning urine specimen, 8 children with IgA nephropathy (IgAN(–)) and 11 children with thin basement membrane disease (TBMD) with no detectable proteinuria. Results: The labeling intensity of glomerular fixed anionic sites from IgAN(+) was significantly lower than that of IgAN(–) and TBMD. Staining the serial sections following methylation treatment revealed that the labeling intensity for fixed anionic sites in TBMD was significantly higher than that of both IgAN(+) and IgAN(–). On the other hand, saponification treatment resulted in significantly more intensive fluorescence in TBMD and IgAN(–) than in IgAN(+). Furthermore, statistical analysis demonstrated a significant correlation between 24-hour protein excretion and the intensity of fixed anionic sites in all patients with IgA nephropathy at pH 7.0 and following staining with saponification treatment. Conclusions: These findings suggest that a reduction of glomerular anionic charge might be causally associated with the development of proteinuria in childhood IgA nephropathy. Furthermore, sulfate components such as heparan sulfate proteoglycan might be involved initially followed by carboxyl components such as sialoglycoproteins in the glomeruli of patients with IgA nephropathy contributing to the occurrence of proteinuria. We suggest that this method represents a straightforward approach to dissect the participation of charged components in the pathogenesis of childhood IgA nephropathy and their relationship to the development of glomerular proteinuria.

Control in Both Backbone and Branch Segment Lengths of Poly(tetrahydrofuran) Polymacromonomers by Electrostatic Self-Assembly and Covalent Fixation

Polymacromonomers are a novel class of branched polymers, composed of a linear backbone segment with densely substituted side chains of either linear, flexible polymer segments1,2 or highly branched, dendritic segments (dendron-jacketed polymers).3-5 They are unique in forming anisotropic cylindrical three-dimensional structures, as observed directly by means of an AFM or SFM technique, where the otherwise flexible backbone segment is forced to adopt an extended rodlike form rather than its entropically favored random-coil form.6-10 In consequence, polymacromonomers can produce, through self-assembly, a variety of mesoscopically ordered structures. The precise control, therefore, over structural parameters in polymacromonomers such as the backbone segment length and the number of graft segments in addition to the graft segment length becomes an important prerequisite for the design and eventual modulation of the supramolecular structures achieved by them. Polymacromonomers of high branch numbers have so far been prepared by a radical homopolymerization process under rigorously controlled conditions.11 While the control over the number of branch segments (the DP of the product) has been difficult to achieve. Very recently, a living radical polymerization process has been applied, and uniform size polymacromonomers have been synthesized using macromonomer molecular weights of a few thousand.12 A macromolecular coupling reaction between a polyfunctional prepolymer and complemental end-functional polymer precursors, on the other hand, is an alternative means to produce a polymacromonomer with controlled structures, since both polymer precursors are, in principle, prepared by a living polymerization technique and fully characterized prior to the coupling reaction.13 In practice, however, polymer coupling processes by conventional reaction mechanisms have scarcely been applied because of the inefficiency by the low concentration of reactive groups located only at the chain end of a polymer precursor, as well as by the repulsive interaction and eventual macroscopic phase separation of two immiscible polymer precursors. We have proposed an effective macromolecular coupling reaction process by addressing the above-mentioned drawbacks.14,15 Thus, a series of poly(THF) polymacromonomers were prepared in high yields by use of poly(THF) having an azetidinium salt,16 as well as a tetrahydrothiophenium salt,17 as a single end group. A highly efficient ion-exchange reaction of the poly(THF) precursor was observed to occur with poly(sodium acrylate), by precipitation of the former into aqueous solution of the latter. During this process an ionically self-assembled product is presumed to be formed, and this has been assumed a critical intermediate for the exceptionally efficient polymer coupling reaction. In this particular reaction, however, the ionically self-assembled precursor could not be isolated, since the azetidinium (four-membered ammonium) group and the tetrahydrothiophenium (five-membered sulfonium) group undergo a quantitative ring-opening reaction by carboxylate anions in poly(acrylate) at ambient condition to produce amino-ester and thio-ester (thus covalent bond) groups, respectively. The isolation of the ionically self-assembled polymacromonomer precursor has subsequently been achieved by use of poly(THF) having a less strained N-phenylpyrrolidinium salt as a single end group.18 The relevant ion-exchange process with poly(sodium acrylate) could produce the ionically self-assembled and isolatable polymacromonomer precursor, and the subsequent heat treatment could convert the ion pair into covalent bond quantitatively to produce a polymacromonomer in high yield. In this relevance, a variety of noncovalently selfassembled, comb-shaped polymers and copolymers either by hydrogen bonds or by ionic interactions have also been reported to exhibit unique phase behaviors in bulk.19-21 As a further extension of our “electrostatic selfassembly and covalent fixation” process, we report herein an efficient synthesis of a series of poly(THF) polymacromonomers with controlled backbone segment length as well as graft segment length. Thus, uniform size poly(THF) having an N-phenylpyrrolidinium salt group was subjected to the coupling reaction with poly(sodium acrylate)s of defined DP values, prepared through the living polymerization of tert-butyl acrylate and subsequent saponification treatment.

Evaluation of 107 legumes for renewable sources of energy

One hundred and seven species of randomly-collected Leguminosae were evaluated for their potential as energy-producing crops. Whole plants, excluding roots, were chemically analyzed, and 11 species were identified as the more promising for future considerations based on a numerical rating system developed at this Center. Botanical, fiber, and protein characteristics of the more promising species that had ratings of less than 11 were considered excellent. Other characteristics, including contents of oil (1.7–3.2%; dry, ash-free, sample basis), polyphenol (5.4–16.5%), and hydrocarbon (0.3–0.6% for 10 species and 2.6% for one), were generally lower than those of promising species in other families previously analyzed. Of the 11 species, one contained principally rubber (polyisoprene) in the hydrocarbon fraction and 7 contained principally wax. Hydrocarbon fractions of 3 species with less than 0.4% were not examined. The oils of species with at least 3.0% oil were examined by thin layer chromatography (TLC) to determine classes of components and were given a saponification treatment to determine yields of unsaponifiable matter and fatty acids. The oil of one species was quantitatively analyzed for classes of compounds by TLC-flame ionization detection. Selected species with ratings greater than 10 are briefly discussed.

Surface modification of polyethylene by radiation-induced grafting for adhesive bonding. III. Oxidative degradation and stabilization of grafted layer

Vapor-phase mutual grafting of methyl acrylate (MA) onto polyethylene (PE) and subsequent saponification treatment produce a surface graft having a high adhesive bondability, which results from the presence of a hydrolized homopolymer layer (consisting of only monomer componenet) on an inner graft copolymer layer consisting of both PE and monomer components. The oxidative deterioration and the stabilization of the grated surface layer have been investigated to clarify the long-term stability of the adhesive bondability. The bondability rapidly disappears with accelerated weatherly followed by acetone extraction treatment, whereas it is kept unchanged during thermal-oxidative aging at 100/sup 0/C. Microscopic and attenuated total resonance (ATR) infrared spectroscopic observations of the degreaded surfaces show that the bondability loss is due to degradiative removal of the surface homopolymer layer. The addition of combinations of conventional antioxidants and ultraviolet absorbers stabilizes the grafted surface layer against thermal-oxidative and photo-oxidative degradation and thus extends the bondability rentention time. The stabilization is more effective in the grafts of carbon black-containing PE, where carbon black is present in the inner-graft copolymer layer.

Surface modification of polyethylene by radiation-induced grafting for adhesive bonding. I. Relationship between adhesive bond strength and surface composition

A number of vinyl monomers have been surface grafted onto a polyethylene sheet by the mutual irradiation in monomer vapor and by a trapped-radical technique. The surface composition of the grafted sheets has been determined by means of ATR infrared spectrophotometry and compared with the peel strength of the joints bonded with conventional structural adhesives. In the methyl acrylate grafts followed by a saponification treatment, only the surfaces having graft compositions of more than 80 mole-% methyl acrylate give a high peel strength. A similar relationship between peel strength and surface composition is found in the surface grafts of vinyl acetate, acrylic acid, acrylamide, and methylolacrylamide. It is concluded that the formation of a surface with such a high monomer content is a necessary condition for the strong adhesive bonding of grafted polyethylenes at bonding temperatures below the softening point. Moreover, the adhesive bondability of the highly modified surfaces with epoxy adhesives is significantly enhanced by the introduction of carboxy and carbamyl radicals.

The structure of branched polymers of diallyl phthalate

AbstractThe complete characterization of a branched polymer involves many factors, the most difficult to assess being the average number of elementary linear portions, or branches, of which the polymer is composed, the degree of polymerization of the branches and the extent of cyclic structure formation. A method of analysis of branched polymers is proposed which should be applicable to polymers of any polyfunctional monomer the unsaturated groups of which are separated by saponifiable links. The method is based on the measurement of degree of polymerization and residual unsaturation of the polymer followed by saponification and determination of degree of polymerization of the resulting polymer, and involves the assumptions that branching in the polymer occurs only by the sharing of a monomer unit by two or more linear portions or branches depending on the number of double bonds in the monomer and also that the average degree of polymerization of the branches remains unchanged by the saponification treatment. Evidence from experiments on the saponification and re‐esterification of poly(allyl acetate) and poly(allyl benzoate) indicates, that, in the case of diallyl esters, the above conditions are satisfied. The technique was therefore applied to three polymers of diallyl phthalate, and in each case the average number of chains and degree of polymerization of the chains were estimated. Evidence of considerable extents of cyclic structure formation was found, each individual branch in the polymers consisting of approximately fourteen diallyl phthalate units, six of which are doubly reacted. It is suggested that the existence of extensive formation of cyclic structures may be partly responsible for the poor correlation of predicted with actual degrees of conversion at gelation in polymerizations involving multifunctional monomers.