polyurethane refers to a polymer containing a carbamate chain end (-nh-coo-) in the molecular structure, but the carbamate chain segment is not in the polymer not the dominant segment. they are the product of the stepwise polymerization reaction of hydroxyl-terminated polymers such as polyether polyols or polyester polyols with isocyanates. due to the variety of raw material sources, it is usually not possible to represent all polyurethanes in a general empirical way.
most of the polyurethanes currently produced are foamed plastics. there are soft, semi-rigid and rigid foam products. in addition, there are various polyurethane products such as elastomers, coatings, adhesives, fibers, films, etc.
polyurethane foam can be classified according to raw materials, production process and product performance.
according to the type of polyol used, it can be divided into polyether type, polyester type and so on. due to factors such as raw material source, price and performance, polyether foam currently accounts for more than 90% of the total soft foam, and is the dominant type. polyester foam is still reserved in some special applications due to its excellent solvent resistance and other properties. with a market share of 5%-10%.
from the perspective of product load-bearing performance, polyurethane soft foam can be divided into ordinary type and high load-bearing type and high resilience type three categories, in addition to slow rebound, self-skinning, super soft, hydrophilic foam, network foam and other special foams.
if it is divided by the isocyanate used, there are mainly three types: tdi, mdi and tdi/mdi mixed type. at present, tdi is still mainly used as raw material in the production of block foam, but in recent years, the all-mdi type high-resilience soft foam block has shown a strong growth momentum; and in molded foam, tdi/mdi mixed isocyanate and all mdi has been widely adopted and is on the rise.
from the perspective of synthesis process, most of them adopt one-step method, and only in a few special occasions, pre-polymerization method (two-step method) or semi-prepolymerization method is used.
from the perspective of production methods, there are continuous and batch methods. the continuous method is the main production process of slab foam. at present, more than 80% of the soft foam is produced by this method, and the slab foam is cut and processed into the required foam parts. the batch molding process is mainly used in the occasions where the foam parts of the desired shape are directly foamed in the mold, and the molding process is particularly necessary when producing foams with complex geometric shapes. box-type foam is a form of molding process. due to the flexible and changeable products, it is still widely used in our country at present.
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supplier
市 polyurethane material co., ltd.
®more products
zf-10: efficient low odor blowing catalyst,� type used in the preparation of low-odor polyurethane foam products
zr-50: low odor gel catalyst, providing excellent balance, can be used in polyurethane molded high resilience foam
z-131:response type low odor gel amine catalyst compound
z-130: low odor gel catalyst, balance gel/foaming
zr-70: low odor catalyst for packaging foam and molding foam on vinyl skin good balance of foam and gel
zr-40 (pentamethyldipropylenediamine): especially effective for cold molded high resilience foam , a catalyst with low odor gel and foaming balance
le-310: a low-odor reactive gel catalyst for large sponges, a new lowvoc amine gel catalyst, amine content exceeds 95%
le-530:response type gel catalyst for various polyurethane foam products
dpa: low odor condensation glue catalyst, outstanding balance and versatility to provide good fluidity
tap 1-methyl-4-(2-dimethylaminoethyl)piperazine: excellent trimerization catalyst for improved fluidity
dmdee (2,2′-dimorpholine diethyl ether): strong foaming catalyst, providing a stable pre-set polymer system
dmaee: low density full hydraulic foam and low-density semi-rigid foam
bdmaee bis-(2-dimethylaminoethyl) ether: efficient foaming catalyst
bdma (n,n-dimethylbenzylamine): polyurethane rigid foam catalyst, epoxy accelerator
dmea (n,n’-dimethylethanolamine): neutralize acid in some hard foam systems,
pmdeta (pentamethyldiethylenetriamine): especially effective for hcfc/water-blown hard foam, similar to pc5
