Cellulose blends

Most MF, UF, RO, and NF membranes are synthetic organic polymers. NF membranes are made from cellulose acetate blends, cellulose triacetate (CTA), or polyamide composites such as the RO membranes, or they could be modified forms of UF membranes such as sulfonated polysulfone [27]. On the other hand, poly(vinyl alcohol) (PVA) is a significant polymer for nonaqueous applications. Chemical stmctures of a few of the prominent polymers are shown in Figure 42.4. 

Esterification and Hydrolysis Importance of Hydroxyl Functionality Viscosity Blending Cellulose Acetate (CA)... 

Because of the ever-increasing demand of biodegradable products, different approaches have been made. One such method is the use of biomass as natural biopolymer for the production of biodegradable plastics. Khalid et al. [59] have reported a work done by using cellulose derived from oil palm empty fruit bunch fiber (EFBF). The composites were prepared by blending cellulose and EFB fibers... 

Uses Flame retardant plasticizer for PVC, PVB, PS, ABS-PC blends, cellulosics, rubber, coatings petroleum anti-surface ignition agents in food-pkg. adhesives Regulatory FDA 21CFR 175.105 Manuf/Distrib. Bayer Chem Service FMC Velsicol Trade Names Disflamoll DPK... 

Based on current standard testing methods and specifications, several renewable resource polymers may be considered biodegradable, the foremost being starch blends, cellulosic derivatives, polyhydroxyalkanoates and poly(lactic acid). Several new and old condensation polymers based on monomers obtained from fossil resources, such as polycaprolactone and the Bionolle series from Japan (Showa High Polymers) based on suucinic acid, are also acceptable by current standards, as are there blends with natural polymers such as starch. 

Nylon apparel Nylon bearings Nylon blends Nylon-cellulose Nylon-clay hybrid Nylon-cotton Nylon-cotton blends Nylon engineering Nylon fibers Nylon hollow fibers Nylon-6,1 [25722-07-0]... 

Cotton linters or wood pulp are nitrated using mixed acid followed by treatment with hot acidified water, pulping, neutralization, and washing. The finished product is blended for uniformity to a required nitrogen content. The controlling factors in the nitration process are the rates of diffusion of the acid into the fibers and of water out of the fibers, the composition of mixed acid, and the temperature (see Cellulose esters, inorganic esters). 

Triphenyl phosphate [115-86-6] C gH O P, is a colorless soHd, mp 48—49°C, usually produced in the form of flakes or shipped in heated vessels as a hquid. An early appHcation was as a flame retardant for cellulose acetate safety film. It is also used in cellulose nitrate, various coatings, triacetate film and sheet, and rigid urethane foam. It has been used as a flame-retardant additive for engineering thermoplastics such as polyphenylene oxide—high impact polystyrene and ABS—polycarbonate blends. 

Polymer Blends. The miscibility of poly(ethylene oxide) with a number of other polymers has been studied, eg, with poly (methyl methacrylate) (18—23), poly(vinyl acetate) (24—27), polyvinylpyrroHdinone (28), nylon (29), poly(vinyl alcohol) (30), phenoxy resins (31), cellulose (32), cellulose ethers (33), poly(vinyl chloride) (34), poly(lactic acid) (35), poly(hydroxybutyrate) (36), poly(acryhc acid) (37), polypropylene (38), and polyethylene (39). 

Other blends such as polyhydroxyalkanoates (PHA) with cellulose acetate (208), PHA with polycaprolactone (209), poly(lactic acid) with poly(ethylene glycol) (210), chitosan and cellulose (211), poly(lactic acid) with inorganic fillers (212), and PHA and aUphatic polyesters with inorganics (213) are receiving attention. The different blending compositions seem to be limited only by the number of polymers available and the compatibiUty of the components. The latter blends, with all natural or biodegradable components, appear to afford the best approach for future research as property balance and biodegradabihty is attempted. Starch and additives have been evaluated ia detail from the perspective of stmcture and compatibiUty with starch (214). 

Blends of polyester with cotton (qv) or viscose are first dyed with disperse dyes, then with sulfur dyes (see Fibers, polyester Fibers, regenerated CELLULOSics). Disperse and sulfur dyes can also be appHed simultaneously in a pad—dry—thermofix/chemical reduction pad—steam sequence. In this case, the sulfur dyes cannot be used in thein reduced form because of the effect of the sodium sulfide on the disperse dye. Therefore, this method is confined to the solubilized sulfur dyes or sulfur dyes in the dispersed form. 

A number of after-treatments with polyester copolymers carried out after sodium hydroxide processing are reported to produce a more hydrophilic polyester fabric (197). Likewise, the addition of a modified cellulose ether has improved water absorbency (198). Other treatments used on cotton and blends are also effective on 100% polyester fabrics (166—169). In this case, polymeri2ation is used between an agent such as DMDHEU and a polyol to produce a hydrophilic network in the synthetic matrix (166—169). 

Determination of the thermal decomposition temperature by thermal gravimetric analysis (tga) defines the upper limits of processing. The tga for cellulose triacetate is shown in Figure 11. Comparing the melt temperature (289°C) from the dsc in Figure 10 to the onset of decomposition in Figure 11 defines the processing temperature window at which the material can successfully be melt extmded or blended. 

The phosphonic acid reactive dyes were appHed to cellulose under slightly acid pH rather than alkaline pH required for other ceUulosic reactive dyes. This feature made them especially attractive for one bath appHcation with disperse dyes to cotton/polyester blends. A review of these dyes appears ia Refereace 5. 

The polyester alkyd moulding compositions are also based on a resin similar to those used for laminating. They are prepared by blending the resin with cellulose pulp, mineral filler, lubricants, pigments and peroxide curing agents on... 

Table 11 Synergistic behavior of Nitrogen Compounds on Cellulose-PCP blends...

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