New Developments in the Area of Solvent-Borne Acrylic Pressure-Sensitive Adhesives

Since their introduction half a century ago, acrylic pressure-sensitive adhesives have been successfully applied in many fields. In the last fifty years or so, acrylic pressure-sensitive adhesives (PSAs) have made tremendous strides from what was virtually a black art to what is now a sophisticated science. So much so that larger manufacturers of pressure-sensitive adhesives and even their polymer suppliers now use very expensive equipment to study pressure-sensitive adhesive behavior. The three properties which are useful in characterizing the nature of pressure-sensitive adhesives are tack, peel (adhesion) and shear (cohesion). The first measures the adhesive's ability to adhere quickly, the second its ability to resist removal by peeling, and the third its ability to hold in position when shear forces are exerted. The performances of pressure-sensitive adhesives, such as tack, peel and shear, based on polyacrylates synthesized through co-polymerization of acrylate monomers and formulated in organic solvents mixtures are, to a large degree, determined by the molecular weight of acrylic copolymer, polymerization method and especially by the type and quantity of the crosslinking agent added to the PSA. Newly developed solvent-borne PSAs are used in protective foils, removable and repositionable self-adhesive products, water-soluble PSAs and water-dispersible self-adhesive products, photoreactive UV-crosslinkable self-adhesive tapes, and dual-crosslinkable PSAs for self-adhesive tapes with post-crosslinking potential characterized by enhanced cohesion at higher temperatures. The mentioned water-soluble PSAs, water-dispersible self-adhesive products and photoreactive UV-crosslinkable self-adhesives are synthesized in organic solvents as solvent-borne acrylic PSAs.     

Odor and Structure

In contrast to previous hypotheses that there are a few primary odors, recent results show the existence of an extremely large number of receptors each capable of recognizing a small number of odorants. Although in principle enantiomers have different odors, in many cases the size of the difference is small or even zero. Minor structural change often has a major effect on the odor perceived. Detailed results of structure-odor relationship have been obtained with several classes of odorants. Most investigated are the classes of fatty aldehydes, degraded carotenoids, sandalwood odorants, ambergris and musk compounds. Various rules and correlations have been established. Despite numerous excellent studies during the last 30 years the area of structure-odor relationship remains rather confusing.     

Olfactory recognition of individuals by male cavies (Cavia aperea)

In one study, using a habituation procedure, male South American cavies,Cavia aperea, distinguished individual differences in odors collected from three sources: perineal gland secretions, urine, and supracaudal gland secretions. In a second study, male cavies spent more noninvestigatory time and rested more on the side of a cage containing the odor of a familiar subordinate male as compared to the cage side containing the odor of a familiar dominant male. Since the odor source was a glass plate which had been left in the home cage of the donor males for three days, the actual odorous cue to which the test males responded is not known. These studies demonstrate that male cavies distinguish odors of individuals, that individual differences in odors are found in at least three different sources, and that cavies use chemical cues to distinguish between known individuals.     

车用胶粘剂对车内空气质量的影响

以车用胶粘剂作为研究对象,重点探讨了其VOC(挥发性有机物)含量和气味性能对车内空气质量的影响,并提出了相应的改善措施。研究结果表明:焊装用胶的主要成分为丁基橡胶、加工油和炭黑,三者对VOC含量的影响依次为加工油>炭黑>丁基橡胶,其气味等级(3～4级)属于难闻和反感级别;涂装用胶的主要成分为糊状PVC(聚氯乙烯)树脂、DOP(邻苯二甲酸二辛酯)增塑剂和有机溶剂等,其对整车车内VOC含量影响较大,并且涂装用胶的气味等级(4级)属于反感级别;总装用胶的主要成分为异氰酸酯、聚醚多元醇等,其乙苯含量相对最高,对整车车内的VOC含量影响极大,并且总装用胶的气味等级(1级)属于无法忍受级别。     

Experience-Dependent Modification of Orientational Response to Olfactory Cues in Larvae of Spodoptera littoralis

In a behavioral dual-choice test the orientational response of third-instar larvae of Spodoptera littoralis to a certain odor could be increased, following a former experience of the odor. The odorants used were either the odor of a previously eaten host plant or a synthetic plant odor presented in conjunction with food. Inexperienced third-instar larvae were either neutral or demonstrated a weak attraction to the odors, whereas experienced larvae were highly attracted. Furthermore it was demonstrated that the larvae did not generalize between the odor previously experienced and a novel odor.     

Analysis of characteristic human female axillary odors: Qualitative comparison to males

Odors produced in the human female axillae are of both biological and commercial importance. Several studies have suggested that extracts from female underarm secretions can alter the length and timing of the female menstrual cycle. In addition, more than 1.6 billion dollars are spent annually on products to eliminate or mask the axillary odors. Our recent studies have determined that the characteristic axillary odors in males consist of C₆–C₁₁, saturated, unsaturated and branched acids, with (E)-3-methyl-2-hexenoic acid (3M2H) being the major compound in this mixture. The 3M2H appears to be carried to the skin surface bound to two proteins in the axillary secretions. Data reported here show that the same mixture of odorous compounds is found in female axillary secretions, with several minor qualitative differences. Separation of the female apocrine secretions into aqueous and organic soluble fractions demonstrated that 3M2H, and several other members of the acids in the characteristic odor, are released by hydrolysis with base. Electrophoretic separation of the proteins found in the aqueous phase of female apocrine secretions revealed a pattern identical to that seen in males. The qualitative similarity of the acidic constituents making up the characteristic axillary odors of both females and males as well as the proteins present in the aqueous phase suggest a similar origin for axillary odors in both sexes.     

Do Pine Voles (Microtus pinetorum) Use Numerous Types of Olfactory Cues to Discriminate Gender?

Olfactory cues can contain information for discrimination of gender that can affect subsequent social interactions. Social rodents are hypothesized to use more olfactory cues than nonsocial rodents to distinguish males from females. The generality of this hypothesis was tested using the pine vole (Microtus pinetorum), a social vole. We examined nine possible sources of odors. A slide containing an odor from a male and a female was presented to each test subject for 3 min. We recorded the amount of time each test subject spent investigating each odor. Females spent significantly more time investigating male urine and male anogenital odors; however, they did not use any other odor sources to discriminate gender. In contrast, males did not use any odor sources to discriminate gender. Our results do not support the hypothesis that all social rodents use numerous odor sources to discriminate gender. Instead, our results are consistent with the alternative hypothesis that use of odor sources to convey information about gender may differ in rodents that live in different microhabitats.     

Fruit Odor as A Ripeness Signal for Seed-Dispersing Primates? A Case Study on Four Neotropical Plant Species

Fleshy fruits contain a myriad of secondary metabolites that may fulfill various non-mutually exclusive ecological functions. Among them are defense against pathogens and herbivores, manipulation of frugivores’ gut retention time, or controlling the germination process. In addition, it has been suggested that aroma compounds may be used as fruit-selection cues by frugivores, and that plants may be under selection to provide a reliable signal for ripeness to seed-dispersal vectors through ripe fruit aroma. A previous project demonstrated that fruit odor of two Neotropical primate-dispersed plant species can be used by primates to identify ripe fruits. Here, we provide data supporting the hypothesis that olfactory conspicuousness of ripeness in these two species may be an evolved signal rather than a cue exploited by primates. We analyzed the odors of ripe and unripe fruits of the two species along with odors of two sympatric species whose main dispersal vector is passerine birds. We show that only primate-dispersed species significantly change their odor profiles upon ripening. Thus, odor of bird-dispersed species is not informative regarding their ripeness level and is likely to fulfill other functions. We discuss these data in light of the multiple hypotheses for the presence of fruit secondary metabolites, and we offer a roadmap for future studies to establish the hypothesis that fruit odor is an evolved signal for ripeness.     

Which Chemical Constituents from Dog Feces are Involved in its Food Repellent Effect in Sheep?

This study is an attempt to identity the active chemicals (signal) of the odor of dog feces that suppress feeding in domestic sheep. The repellent effects of the odors of dog, wolf, pig, and sheep feces (potential predator and nonpredator species) were assessed on sheep, using a food-choice situation. The odors of wolf and dog feces had the highest repellent effect. A total pentane extract of dog feces was split by micropreparative gas chromatography and the fractions obtained were analyzed and presented to sheep in a food-choice situation. The quantitatively major constituents of the pentane extract, identified by gas chromatography–mass spectrometry, are indole and fatty acids. In food repellency tests, indole had no repellent effect. The active odorous signal contained in dog feces appears to consist of fatty acids mixed with neutral compounds acting synergically. These experiments underline the complexity of this biological signal and constitute a first step in the development of a practical repellent for ungulates.     

Lack of Evidence for HLA-Linked Patterns of Odorous Carboxylic Acids Released from Glutamine Conjugates Secreted in the Human Axilla

Genetic factors within the major histocompatibility locus (MHC) have been shown to influence body odors in mice. MHC-dependent preferences for body odors also have been reported in humans. The axillary glands are a key odor-forming organ in humans, and it is assumed that they provide behaviorally relevant odors. Volatile carboxylic acids are the most diverse class of known axillary odorants, and the pattern of these acids is genetically determined. These acids are released by an N_α-acyl-glutamine-aminoacylase present in skin bacteria. We tested a hypothesis concerning whether or not the inherited individual-specific patterns of odorous acids are strongly influenced by polymorphic genes in the MHC. Axilla secretions were collected in 12 families, comprising 3 to 6 siblings, who had been typed for HLA-A, B, and DRB1 loci. The samples were treated with N_α-acyl-glutamine-aminoacylase, and the methyl esters of the released acids were analyzed with comprehensive two-dimensional gas chromatography (GC × GC) and time-of-flight mass spectrometry (ToF MS). The patterns of the analytes were compared by distance analysis. The distance was lowest between samples taken from the same individual, confirming the presence of donor-specific odor-prints. A much higher distance was observed between siblings, but there were no differences among siblings sharing none, one, or both HLA-A,B,DRB1 haplotypes. By applying principal component analysis, a clear clustering of samples taken from one individual was confirmed, but no clustering was observed for siblings sharing identical HLA-A,B,DRB1 alleles. Thus, the genetically determined pattern of N-acyl-glutamine conjugates of volatile carboxylic acids, secreted in the human axilla, appears not to be determined by genes residing in the HLA complex.     

Adhesives from Waste Paper by Means of Phenolation

Recently the effective use of woody materials has been of interest from the viewpoint of forestry preservation. Newsprint is one of the most abundant of woody materials which are discarded into the environment after use. They would be, however, easily recovered from the market.

The application of phenolation to cellulosic materials is one possibility for the utilization of waste papers. Phenolation is a newly-established method by which lignocellulosic materials are completely converted to substances soluble in some polar organic solvents.

Waste newsprint is subjected to phenolation in the presence of an acidic catalyst. The phenolated product was then methylolated in order to prepare alkaline curable adheisve resins. The chemical characteristics of the phenolated products were studied and the properties of plywood adhesives from them were evaluated. The results indicated that cellulose decomposed and reacted with phenol, producing complicated compound having a phenolic moiety during phenolation and that the compound reacted with formaldehyde, leading to resinous substance which could be thermoset.

The adhesives from the resins of phenolated newsprint provided comparable properties to a commercial phenolic resin in cure behavior, resin viscosity and tensile bond strength. The products of cellulose phenolation, therefore, are expected to be a source of wood adhesives comparable with phenolic resins.     

Chemical Identification of MHC-influenced Volatile Compounds in Mouse Urine. I: Quantitative Proportions of Major Chemosignals

The genes of the major histocompatibility complex (MHC) are highly polymorphic loci that encode cell surface proteins, class I and II molecules. They present peptide antigens to T cells and thereby control immunological self/nonself recognition. Increasing evidence indicates that MHC genes also influence odor and mating preferences; however, it is unclear how. Here we report the results of chemical analyses of male mouse urinary odors collected from a variety of mouse strains, including MHC-congenics, recombinants, mutants, and transgenics (i.e., beta2 microglobulin "knockouts," which lack class I expression, and transporters associated with antigen processing (TAP) knock-outs). After the identification of volatile odor components by gas chromatography/mass spectrometry, the odor profiles of urine samples were analyzed quantitatively by using stir bar sorptive extraction and gas chromatography/atomic emission detection. Results showed that MHC genes influenced the amounts of testosterone-mediated pheromones, sulfur-containing compounds, and several carbonyl metabolites. This is the first report to quantitatively link known mouse pheromones to classical, antigen-binding MHC loci. Surprisingly, these compounds were not influenced by TAP genes, even though these loci are MHC-linked and play a role in peptide presentation. Whereas identification of MHC-determined odorants does not reveal their metabolic origin, some constituents were also present in blood serum, and their levels were not altered by antibiotics.     

Flavors and odors of fish oils

Off odors and flavors in fish oils arise from contamination from metabolites, from the spoilage of fish protein, or from oxidation products of the oil itself. The resulting odors and flavors can render the oil less desirable for many applications. Odors or flavors in the flesh of animals or poultry fed fish oil come more from the polyunsaturated nature of the fish oil than from the oxidation products or flavor and odor of the oil that is fed. Odors and flavors can be removed by refining methods or in some cases, masked by use of certain additives. National Marine Fisheries Service, U.S. Department of Commerce.     

Analysis and removal of the stench emitted from indoor dust

The offensive odor produced from indoor dust accumulated inside a vacuum cleaner is quite unpleasant to the user. In this study, the odor of dust samples prepared under various conditions was examined using an olfactory method that employs the human sense of smell. In addition, the odorous compounds were analyzed by GC-MS. The odor intensity of the dust collected inside the vacuum cleaner increased in proportion to not only the humidity and temperature of the dust, but also to the cleaning period of the container where indoor dust was accumulated. GC/MS confirmed aldehydes to be the main odorous compounds. The dilution ratio at which the stench of the indoor dust was not detected was determined by using the triangle odor bag method.     

Pulsed Odors from Maize or Spinach Elicit Orientation in European Corn Borer Neonate Larvae

Lepidoptera larvae are capable of orienting towards or away from plants by using odors as cues but whether this attraction is innate or secondarily acquired remains unknown. We tested the hypothesis that European corn borer (ECB) neonate larvae express an innate attraction towards odors released from maize, and avoidance towards odors from spinach. Neonate larvae were placed on a locomotion compensator within a constant stream of humidified air that was loaded intermittently with airborne odors drawn from potted plants. The odor stream was delivered continuously or pulsed (1 to 10 sec pulses) at 40 ml/min. ECB larvae oriented toward maize odors pulsed at 2 to 6 sec but walked away from maize odors delivered at lower frequencies (9 and 10 sec pulses or to continuous ones). They consistently walked away from spinach odors, irrespective of the pulsing regime except at 1 sec pulses that did not elicit orientation. We further explored odor intensity on orientation towards maize odors by adjusting the odor stream intensity. At higher intensity (60 ml/min), the direction reversal started at the 6 sec half period, while at lower intensity (20 ml/min), it showed up only for the continuous stimulus. ECB larvae exhibit a striking ability to lock on to a direction, which they maintained despite gaps of up to 10 sec in the odor stream. Our results demonstrate that ECB neonate larvae express innate orientation preferences towards natural odors from plants. These reactions correlate well with the biological value of these plants for ECB: maize generally is accepted by ECB larvae and adults, while spinach represents a poor host because it produces (non-volatile) phytoecdysteroids that are toxic and deterrent.     

Field method for sampling chemicals released by active insects

An inexpensive, silent, maintenance-free suction/adsorption system is described for efficiently collecting submicrogram quantities of odors over a wide range of volatilities under field conditions. The samples can later be submitted to gas chromatographic-mass spectrometric analyses. An example is given with odors sampled from solitary bees engaged in digging and defensive behaviors at their nesting sites. Gas chromatograms of odor samples collected from known concentrations of synthetic chemicals are provided for standardization.     

Behavioral responses of sexually active mud snails: kariomones and pheromones

We postulated that kariomones and pheromones function to organize egg capsule deposition and breeding aggregations of mud snails (Ilyanassa obsoleta). Sexually active male and female mud snails were exposed to water-born odors from juvenile snails, nonaggregated female snails, oysters, egg capsule depositing snails, sexually active males, sexually active females, and copulating snails and tested for a follow response using a ring assay. Neither sex responded to juvenile odor or to odor of sexually inactive females. Snails turned and followed water born odors from oysters. when tested with the odors of sexually active males, sexually active females, and copulating pairs, we found sex-specific differences in responses. Sexually active females followed the odor of sexually active males and ignored sexually active female odor. Sexually active males followed the odor of sexually active females and ignored sexually active male odor. Both sexes followed the odor of copulating pairs and egg capsule depositing snails. Snail activities in breeding aggregations are organized by at least three pheromones and one kariomone, and reflect the multifunctionaLity of the aggregations.     

国内水性聚氨酯胶粘剂产品及应用现状

分析了国内水性聚氨酯胶粘剂应用现状,对国产水性聚氨酯胶粘剂与国外产品及溶剂型产品的使 用性能作了对比检测,指出国内产品的性能已经取得很大进步,完全可以满足使用要求,并对产品使用性能 的研究开发动向作了深入的讨论。     

Misidentification by wild rabbits,Oryctolagus cuniculus,of group members carrying the odor of foreign inguinal gland secretion

The experiments described in this paper are part of a series designed to clarify the behavioral function of the odor of the secretion from the inguinal glands of rabbits,Oryctolagus cuniculus. Results are presented of tests carried out on 48 mixed-sex groups consisting of 162 adult wild-type rabbits, 48 males and 114 females. The subordinate females of the groups were smeared with various odorous materials and the reactions of their pen-mates towards them recorded. Eight sources of natural rabbit odors and a commercial perfume were used in 198 tests. A high proportion (60%) of the subordinate females smeared with the inguinal gland secretions from unfamiliar males were attacked, mainly by the males, which were generally the most dominant individuals within the groups. The paper also presents statistical analyses of behavioral data collected during two earlier related experiments with single-sex groups involving 258 rabbits in 300 tests which have not previously been evaluated. The results throughout the whole study indicate clearly that the odor of the inguinal gland secretion of rabbits carries information which affects the acceptance of individuals by their companions in organized groups. Other sources of unfamiliar rabbit odor did not influence the attitude of groupmates toward the individuals smeared with them, or if they did, their effects were only marginal.