ISSN:0032-3888    

DOI:10.1002/pen.760170502

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractThe protein collagen is a major constituent of mammalian tissue. Treatment of calfskin with an enzyme under acid conditions simultaneously solubilizes much of the collagen and removes non‐helical telopeptides which are believed to contribute to immune response. Then, the solid collagen can be reconstituted by precipitating the solubilized material with weak alkali. Films from the enzyme‐treated, acid‐soluble collagen are strengthened by cross‐linking with glutaraldehyde. Composite films are made by coprecipitating collagen (from a solution) with an acrylic resin (from a latex). In one example, an acrylic resin to collagen ratio of 1:3 gives a wet‐tensile strength about 30 percent higher than that for collagen alone. The tensile strength range of these wetted films (20 to 30 megapascals) is typical of the upper range for such limp films as polyethylene. On the other hand, ‘bone‐dry’ collagen has a higher strength similar to that of glassy polymers such

ISSN:0032-3888    

DOI:10.1002/pen.760170503

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractTen polyfunctional vinyl‐type monomers were graft polymerized with butyl acrylate or methyl methacrylate onto chromium‐tanned collagen in a redox initiated, emulsion‐type system. The thickness of the grafted leathers showed an increase ranging from 9 to 159 percent. The regression of total polymer on thickness gave a better fit than did bound polymer, the correlation coefficient being 0.774. The tensile load at break increased in all but one case, with a maximum increase of 70 percent over the control. Since the thickness increase was usually greater than the load increase, the tensile strength usually decreased. The changes, in tensile elongation were not always in agreement with those anticipated from crosslinked bulk polymers. In addition to these physical effects, inclusion of the polyfunctional comonomers generally reduced the amount of extractable polymer. A hypothesis is proposed to explain some of the observed ef

ISSN:0032-3888    

DOI:10.1002/pen.760170504

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractPolystyrene 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 vulcan

ISSN:0032-3888    

DOI:10.1002/pen.760170505

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractEthylene/ethyl acrylate/carbon monoxideterpolymers (E/ EA/CO) can exhibit a very high degree of miscibility with poly(vinyl chloride) as determined from dynamic mechanical measurements. The blends yield transparent films and show a large amorphous phase which exhibits only one major glass transition. However, some crystallinity can be detected and has been measured by differential, scanning calorimetry. Residual crystallinity is at least partially due to the somewhat non‐uniform nature of the terpolymerization. The acrylate monomer exhibits faster polymerization rates than the other two constituents. By contrast, ethylene/ethyl acrylatcopolymers are not miscible with poly(vinyl chloride). The addition of carbon monoxide to the termpolymer structure is believed to yield miscibility with poly(vinyl chloride) via specific interaction of the ketone carbonyl of the terpolymer (proton acceptor) and the tertiary hydrogen of poly(vinyl chloride) (proton donor). This specific interaction allows for a broad range of terpolymer compositions which retain miscibility with polyvinyl chloride. Similar results are also observed with ethylene/vinyl acetate/carbon monoxide (E/VA/CO) as well as ethylene/2‐ethylhexyl acrylate/carbon monoxide termpojymers. The vinyl acetate terpolymers (and their blends) display a lower degree of crystallinity than the E/EA/ CO. This is consistent with the more uniform nature of the E/VAJCO terpolymerizat

ISSN:0032-3888    

DOI:10.1002/pen.760170506

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractPulp mill wood residue was tested for its suitability as a filler for polyolefins. Samples of wood residue (residue from screened chips) were obtained from three southern kraft pulp mills. Screen analysis of the residues indicated that from 2 to 10 percent, by weight, passes a 48 mesh screen. The aspect, or length to diameter, ratio of the wood residue varied from 3 to over 19, compared to 2.5 for commercial wood flour. While the ash content of the residue was high, its lower cost and higher aspect ratio compared to wood floor indicated potential as a polymer filler. Composites of polyethylene and polystyrene with the wood residue were extruded and then injectionmolded into tensile bars. The results indicate little difference in extrusion torque, tensile modulus, or drop‐ball impact strength between composites containing wood residue and wood flou

ISSN:0032-3888    

DOI:10.1002/pen.760170507

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractA series of starch graft copolymers and one cellulose graft copolymer were prepared containing 40‐50 percent synthetic polymer. The monomers used (styrene, methyl methacrylate, methyl acrylate, and butyl acrylate) were chosen to give grafted synthetic polymers with varying glass transition temperatures (Tg). These graft copolymers were extruded, in the absence of any added thermoplastic homopolymer, to give strong, continuous polysaccharide‐filled plastics which are biodegradable and which exhibit little or no die swell. Properties of plastics varied with the Tgof the thermoplastic portion. Starch‐g‐polystyrene and starch‐g‐poly(methyl methacrylate) were hard and brittle, while graft copolymers prepared from methyl and butyl acrylate were more flexible and leathery. The graft Uopolymers with lower Tggrafts required less torque and could be extruded at lower temperatures. In the methyl acrylate series, a graft copolymer prepared from gelatinized starch was more easily extruded than one prepared from granular starch, and addition of water produced a water‐filled extrudate of excellent quality. The surprising feature of these results is that the matrix polymers, starch and cellulose, are rigid, nonsoftening materials. Grafting of a thermoplastic polymer to these matrix polymers would not be expected to give an extrudable product. The results are explained as powder flow followed by fusion or sintering of the graft polymers under the temperature and pressure conditio

ISSN:0032-3888    

DOI:10.1002/pen.760170508

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractA new type of interlaced mat made of heavy denier nylon monofilaments has been developed, and has been under evaluation for the past few years. Due to its combination of unique properties—high strength, great porosity, chemical stability—it is finding uses in many varied applications. Its current greatest use is in soil erosion control, where the product, when placed on steep banks, traps soil particles caused by runoff water, thus preventing erosion and providing a good seed bed for grasses and other ground cover. Placed under turf and sods, the structure provides a porous, open structure which holds moisture and enhances root growth, while the mechanical strength of this material reduces packing of the soil, thus making a superior base for athletic fields and playgrounds. The product, its properties, and its applications are descri

ISSN:0032-3888    

DOI:10.1002/pen.760170509

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractThis paper briefly reviews the technological status of civil engineering fabrics used for ground stabilization and drainage applications. The theory of how such fabrics work is used to illustrate the advantages of fabric‐containing designs over conventional construction techniques. A drainage project which could not have been completed except at an exorbitant cost without the use of a properly designed filter fabric is detailed, and the economic benefits of using fabrics under ordinary circumstances are also documented. Because fabrics work and because they save money, the outlook for civil engineering fabrics is extremely brigh

ISSN:0032-3888    

DOI:10.1002/pen.760170510

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractMortar specimens were impregnated with methyl methacrylate, n‐butyl acrylate, styrene, and crosslinking agents in various combinations. After polymerization of the monomers in situ, studies of mechanical properties such as Young's modulus and compressive strength were made. In one experiment, various ccpolymers of methyl methacrylate and n‐butyl acrylate were prepared and tested as a function of temperature. Excellent reinforcement was obtained with any combination of monomers as long as the resulting polymer was at a temperature below its glass transition temperature. This suggests that the modulus of the reinforcing polymer is crucial, glassy behavior being required. The addition of crosslinking agents such as TMPTMA increased the high temperature strength, howe

ISSN:0032-3888    

DOI:10.1002/pen.760170511

出版商:Society of Plastics Engineers, Inc.    

年代:1977

数据来源: WILEY