摘要:
Disclosed are polymeric additives for concrete formed of a polyoxymethylene (POM) copolymer. POM copolymers can be utilized to form fibrous additives for concrete, i.e., microfibers and/or macrofibers. The POM copolymers can include one or more chemical groups, e.g., end groups and/or pendant groups that can increase the polarity of the POM and increase the hydrophilicity of the formed fibers, which can improve miscibility of the fibers in wet concrete. Chemical groups of the POM copolymers can bond with components of the concrete or can hydrolyze to form groups that can bond with components of the concrete, e.g., form covalent or noncovalent (e.g., electrostatic or ionic) bonds with one or more components of the concrete binder.
摘要:
A process for the preparation of polyoxymethylene copolymers, wherein 1,3,5-trioxane is polymerized with generally known comonomers in the presence of a strong protonic acid initiator and in the presence of a formaldehyde dialkyl acetal, and wherein the initiator is dissolved in the formaldehyde dialkyl acetal before admixing to the trioxane and the comonomers.
摘要:
The present invention relates to a process for the preparation of oxymethylene polymers as well as oxymethylene polymers obtainable therefrom. The process includes polymerization of a monomer, which forms —CH2—O— units in the presence of an acetal of formaldehyde or a polyhydric alcohol and an initiator for cationic polymerization. The initiator may be a heteropoly acid or an acid salt thereof which is dissolved in an alkyl ester of a polybasic carboxylic acid.
摘要:
A powder containing a polyoxymethylene polymer for coating metallic substrates is described. The polymeric particles are made from a polymeric composition containing a polyoxymethylene polymer having functional terminal groups. The polyoxymethylene polymer is blended with at least one functional additive. The functional additive can decrease the stiffness of the polyoxymethylene polymer, can decrease the shrinkage properties of the polyoxymethylene polymer and/or increase adhesion of the polymer to metal surfaces.
摘要:
Disclosed are polymeric additives for concrete formed of a polyoxymethylene (POM) copolymer. POM copolymers can be utilized to form fibrous additives for concrete, i.e., microfibers and/or macrofibers. The POM copolymers can include one or more chemical groups, e.g., end groups and/or pendant groups that can increase the polarity of the POM and increase the hydrophilicity of the formed fibers, which can improve miscibility of the fibers in wet concrete. Chemical groups of the POM copolymers can bond with components of the concrete or can hydrolyze to form groups that can bond with components of the concrete, e.g., form covalent or noncovalent (e.g., electrostatic or ionic) bonds with one or more components of the concrete binder.
摘要:
A process for the preparation of polyoxymethylene copolymers, wherein 1,3,5-trioxane is polymerized with generally known comonomers in the presence of a strong protonic acid initiator and in the presence of a formaldehyde dialkyl acetal, and wherein the initiator is dissolved in the formaldehyde dialkyl acetal before admixing to the trioxane and the comonomers.
摘要:
A powder containing a polyoxymethylene polymer for coating metallic substrates is described. The polymeric particles are made from a polymeric composition containing a polyoxymethylene polymer having functional terminal groups. The polyoxymethylene polymer is blended with at least one functional additive. The functional additive can decrease the stiffness of the polyoxymethylene polymer, can decrease the shrinkage properties of the polyoxymethylene polymer and/or increase adhesion of the polymer to metal surfaces.
摘要:
The present invention relates to a process for the preparation of oxymethylene polymers as well as oxymethylene polymers obtainable therefrom. The process includes polymerization of a monomer, which forms —CH2—O— units in the presence of an acetal of formaldehyde or a polyhydric alcohol and an initiator for cationic polymerization. The initiator may be a heteropoly acid or an acid salt thereof which is dissolved in an alkyl ester of a polybasic carboxylic acid.